Current Concepts in ACL Injury, Surgery, and

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Current Concepts in ACL Injury, Surgery, and Rehabilitation Zakariya H. Nawasreh, Elizabeth A. Wellsandt, David S. Logerstedt

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Current Concepts in ACL Injury, Surgery, and Rehabilitation

By Zakariya H. Nawasreh, BS, MS Elizabeth A. Wellsandt, DPT David S. Logerstedt, PT, PhD, MPT, MA, SCS 4 clock hours will be awarded upon successful completion of this course.

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ABOUT THE AUTHOR Zakariya H. Nawasreh, BS, MS, graduated with a bachelor of science degree in physical therapy from Jordan University of Science and Technology in 2006 and a master of science degree in health and rehabilitation sciences from the University of Pittsburgh in 2011. He has worked as a teaching assistant and supervised students’ clinical training in the applied medical sciences at Jordan University of Science and Technology. He is pursuing a doctorate in biomechanics and movement science at the University of Delaware, with a focus on operative and nonoperative ACL intervention and outcomes. Elizabeth A. Wellsandt, DPT, received her doctorate in physical therapy and bachelor of science degree in medicine from the University of Nebraska Medical Center, Omaha, in 2009. From 2009 to 2011, Dr. Wellsandt worked as a physical therapist in multiple outpatient orthopedic clinics across the United States, providing care to patients with ACL injuries – both those with access to standard medical treatment and those in medically underserved communities where nonoperative treatment was their only option. She is currently pursuing her doctorate in biomechanics and movement science at the University of Delaware, with a focus on operative and nonoperative ACL intervention and outcomes. David S. Logerstedt, PT, PhD, MPT, MA, SCS, graduated with a bachelor of science degree in health and human performance from the University of Montana and a master of arts degree in exercise physiology from the University of North Carolina. He earned a master’s degree in physical therapy from East Carolina University and a doctorate in the interdisciplinary program of biomechanics and movement science from the University of Delaware. He completed a postdoctoral research position in knee osteoarthritis and total knee arthroplasty with Drs. Lynn SnyderMackler and Joseph Zeni, Jr. Dr. Logerstedt is currently a research assistant professor and interim academic director of the sports residency in the department of physical therapy at the University of Delaware. Dr. Logerstedt has been a practicing rehabilitation specialist for more than 15 years and is board certified in sports physical therapy. He was a physical therapist at the athletes’ Olympic Village polyclinic at the 2002 Salt Lake City Winter Olympics. He has presented his research on ACL and knee disorders at national and international conferences and has published in prestigious sports medicine journals on ACL injuries. The authors have disclosed that they have no significant financial or other conflicts of interest pertaining to this course book. ABOUT THE PEER REVIEWER Trevor A. Lentz, PT, SCS, CSCS, is a physical therapist at the University of Florida Health Orthopaedics and Sports Medicine Institute in Gainesville. He received his master’s degree in physical therapy from the University of Florida and completed a postgraduate sports residency through the University of Florida Health Shands Rehab/University of Florida Clinical Residency Program in 2007. He specializes in the rehabilitation of sports https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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related orthopedic knee and shoulder injuries. Mr. Lentz has authored and coauthored numerous peerreviewed publications and abstracts, as well as presented nationally on the topic of ACL reconstruction outcomes and psychosocial factors in rehabilitation. He currently serves as a reviewer for the Journal of Orthopaedic & Sports Physical Therapy and has been a guest lecturer for the musculoskeletal practice curriculum in the Department of Physical Therapy at the University of Florida. Trevor A. Lentz has disclosed that he has no significant financial or other conflicts of interest pertaining to this course book. Physical Therapy Planner: Julie Heinrichs, DPT The planner has disclosed that she has no significant financial or other conflicts of interest pertaining to this course book. Copy Editor: Diane Hinckley, BA Indexer: Mary Kidd Western Schools’ courses are designed to provide healthcare professionals with the educational information they need to enhance their career development as well as to work collaboratively on improving patient care. The information provided within these course materials is the result of research and consultation with prominent healthcare authorities and is, to the best of our knowledge, current and accurate at the time of printing. However, course materials are provided with the understanding that Western Schools is not engaged in offering legal, medical, or other professional advice. Western Schools’ courses and course materials are not meant to act as a substitute for seeking professional advice or conducting individual research. When the information provided in course materials is applied to individual cases, all recommendations must be considered in light of each case’s unique circumstances. Western Schools’ course materials are intended solely for your use and not for the purpose of providing advice or recommendations to third parties. Western Schools absolves itself of any responsibility for adverse consequences resulting from the failure to seek medical, or other professional advice. Western Schools further absolves itself of any responsibility for updating or revising any programs or publications presented, published, distributed, or sponsored by Western Schools unless otherwise agreed to as part of an individual purchase contract. Products (including brand names) mentioned or pictured in Western Schools’ courses are not endorsed by Western Schools, any of its accrediting organizations, or any state licensing board.

COPYRIGHT© 2014—Western Schools. All Rights Reserved. No part(s) of this material may be reprinted, reproduced, transmitted, stored in a retrieval system, or otherwise utilized, in any form or by any means electronic or mechanical, including https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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photocopying or recording, now existing or hereinafter invented, nor may any part of this course be used for teaching without written permission from the publisher.


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INTRODUCTION

COURSE OBJECTIVES After completing this course, the learner will be able to: 1. Identify the major components of the anterior cruciate ligament (ACL) and its relationship to arthrokinematics of the knee. 2. Discuss the etiology and clinical course typically seen after ACL injury and reconstruction. 3. Identify the risk factors associated with noncontact ACL injury. 4. Describe the components of a comprehensive clinical examination for patients with a suspected ACL injury. 5. Classify patients as potential copers or noncopers to assist in decision making regarding management following ACL injury. 6. Formulate a treatment progression using clinical strategies and evidencebased interventions after ACL injury and reconstruction. 7. Recognize the clinical outcomes after ACL injury and reconstruction.

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njury to the anterior cruciate ligament (ACL) can be devastating. An estimated 80,000 to 250,000 ACL injuries occur each year in the United States. ACL injuries are the most prevalent of internal knee lesions and can result in shortterm physical impairments and longterm joint morbidity. The purpose of this intermediatelevel course is to provide physical therapists and physical therapist assistants with an overview of the etiology and risk factors of isolated ACL injuries; to discuss pertinent clinical examination, classification, and prognosis after ACL injuries and reconstruction; and to review interventions relevant to successful outcomes after injury or surgery. With the modifications and advancements in ACL surgical procedures and the proliferation of research on interventions and outcomes, many clinicians find it difficult to keep apprised of the latest evidence and integrate into their clinical practice new information that could have a direct impact on patient outcomes. Decisions regarding which patients are appropriate for nonoperative management of an ACLdeficient knee, how to safely progress patients through a criterionbased guideline, and when to provide recommendations for safe return back to sports after ACL injury or reconstruction are challenging. Physical therapists and physical therapist assistants will be able to use the knowledge and skills outlined in this course with their patients immediately after ACL injury or https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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surgery in order to maximize patients’ response to exercise at their current functional level while minimizing risk of injury to the healing tissue.


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CURRENT CONCEPTS IN ACL INJURY, SURGERY, AND REHABILITATION INCIDENCE

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njury to the anterior cruciate ligament (ACL) is the most prevalent of internal knee lesions, with upwards of 250,000 ACL injuries occurring each year in the United States (Frank & Jackson, 1997; Griffin et al., 2000; Majewski, Susanne, & Klaus, 2006). More than 127,000 ACL reconstructions are performed annually, making it the sixth most common ortho pedic procedure in the United States (Hughes & Watkins, 2006; Kim, Bosque, Meehan, Jamali, & Marder, 2011). A tear is most likely to occur in the midsubstance of the ACL during lowimpact injuries, as seen in sporting activities (Kennedy, Hawkins, Willis, & Danylchuck, 1976; Noyes, DeLucas, & Torvik, 1974). Research shows that 20.3% of all athletic knee injuries sustained over a 10year period were ACL injuries (Majewski et al., 2006). Approximately 30% of all ACL injuries are contact in nature (Hewett, Stroupe, Nance, & Noyes, 1996). The incidence of noncontact ACL injuries is greater in sports that require multidirectional activities, such as rapid deceleration, pivoting, cutting, and landing from jumps (Griffin et al., 2006). Sports activities account for 88% of injuries to the ACL, although ACL injuries from motor vehicle accidents and mishaps at work have also been reported (Magnussen et al., 2010). In the United States, most ACL injuries occur in young athletes (Wojtys & Brower, 2010) and those of various ages who participate in basketball, soccer, football (Magnussen et al., 2010), and downhill skiing (Pujol, Blanchi, & Chambat, 2007).

FUNCTIONAL ANATOMY

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he ACL originates on the medial side of the lateral femoral condyle and runs through the intercondylar fossa to insert onto the medial tibial eminence (Figure 1). It can be divided into 2 functional bands, the anteromedial and postero lateral bundles (Petersen & Zantop, 2007). These 2 bands play different roles depending on the degree of knee flexion. The anteromedial bundle remains taut throughout the full degree of knee range of motion, with increased tightening near full flexion (Amis & Dawkins, 1991; Sapega, Moyer, Schneck, & Komalahiranya, 1990). The posterolateral bundle is taut in full extension and in deep flexion but slackens throughout the midrange of motion. The ACL is the primary restraint to anterior translation of the tibia relative to the femur and a major secondary restraint to internal rotation, particularly when the joint is near full extension (Duthon et al., 2006). Normal knee arthrokinematics is maintained with the ACL, along with the posterior cruciate ligament (PCL), through the https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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fourbar linkage system (Muller, 1983). The fourbar linkage system is a model of the knee in which the ACL and PCL are depicted as rigid bars connecting to the femur and tibia. The restraints of these ligaments help to control roll and glide in the knee joint throughout a full range of motion. Damage to the ACL can disrupt this system, resulting in aberrant motion during activity. FIGURE 1: KNEE ANATOMY

Note: Retrieved from http://publications.usa.gov/USAPubs.php?PubID=5713

MECHANISM OF INJURY

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amage to the ACL can result from a contact or a noncontact injury. An estimated 70% of ACL injuries result from noncontact mechanisms (Hewett, Myer, & Ford, 2006). Injuries are often reported during activities involving cutting, changing direction, or landing from a jump; landing on the foot instead of toes and being perturbed before landing both increase the risk of ACL injury (Griffin et al., 2006). Shimokochi and Shultz performed a systematic review of studies published through 2007 examining the mechanics of noncontact ACL injury (Shimokochi & Shultz, 2008). They concluded that noncontact ACL injuries are likely to happen during deceleration and acceleration motions with excessive https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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quadriceps contraction and reduced hamstring cocontraction at or near full knee extension. ACL loading was higher during these situations: the application of a quadriceps force when combined with knee internal rotation; a valgus load combined with knee internal rotation; or excessive valgus knee loads applied during weightbearing, decelerating activities (Shimokochi & Shultz, 2008). Patients with a noncontact mechanism of injury may demonstrate increased dynamic knee instability compared with those suffering contact injuries (Hurd, Axe, & SnyderMackler, 2008b).

CLINICAL COURSE

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he sequelae of ACL injury include quadriceps strength deficits, neuromuscular dysfunction, biomechanical maladaptations, and the development of knee osteoarthritis (Daniel et al., 1994; Lohmander, Ostenberg, Englund, & Roos, 2004; von Porat, Roos, & Roos, 2004). However, because individuals do not respond uniformly to an acute ACL injury, outcomes can vary. Most of those who have suffered such an injury decrease their activity levels both in the short and longterm (Ageberg, Pettersson, & Friden, 2007; Ageberg, Thomee, Neeter, Silbernagel, & Roos, 2008; Muaidi, Nicholson, Refshauge, Herbert, & Maher, 2007; Neeter et al., 2006; Tagesson, Oberg, Good, & Kvist, 2008; Tsepis, Vagenas, Ristanis, & Georgoulis, 2006). Nonoperative management of patients with ACL deficient knees can be effective for those who are willing to avoid highrisk activities (Beynnon, Johnson, Abate, Fleming, & Nichols, 2005). However, between 23% and 42% of ACL patients choose to return to highlevel activities after nonoperative rehabilitation (Hurd, Axe, & SnyderMackler, 2008a; Kostogiannis et al., 2007). The standard of care followed by the majority of surgeons for ACL injury in the United States for young, active individuals is early ACL reconstruction (Delay, Smolinski, Wind, & Bowman, 2001; Dye, Wojtys, Fu, Fithian, & Gillquist, 1999). Epidemiological studies have found that patients who are male, younger, Caucasian, of higher socioeconomic status, and who possess private health insurance are more likely to have ACL reconstruction than nonoperative treatment (Collins, Katz, DonnellFink, Martin, & Losina, 2013). Athletes who wish to return to highlevel sports involving pivoting activities are often advised to undergo early ACL reconstruction because of the assumed inevitable knee instability with sportsrelated activities (Johnson, Maffulli, King, & Shelbourne, 2003; Marx, Jones, Angel, Wickiewicz, & Warren, 2003; Myklebust & Bahr, 2005). However, some patients are able to postpone surgery following a period of intense rehabilitation in order to finish out the athletic season or a busy season of work without further episodes of giving way (Fitzgerald, Axe, & Snyder Mackler, 2000a). ACL reconstruction has the most to offer those people with recurrent instability who must perform multidirectional activity as part of their https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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occupation or sport (Arroll et al., 2003). However, surgical reconstruction of the ACL does not ensure a return to previous levels of activity or prevent future joint degeneration (Ardern, Webster, Taylor, & Feller, 2011a, 2011b; Gobbi, Domzalski, Pascual, & Zanazzo, 2005; Nakayama, Shirai, Narita, Mori, & Kobayashi, 2000). Many people may continue to exhibit knee instability, pain, quadriceps strength deficits, or reduced range of motion that may make them unable to return to or maintain a high level of competition (de Jong, van Caspel, van Haeff, & Saris, 2007; Hartigan, Axe, & SnyderMackler, 2010; Keays, BullockSaxton, Keays, & Newcombe, 2001). The risk of developing knee osteoarthritis is the same whether a person chooses nonoperative management or ACL reconstruction (Lohmander et al., 2004; Myklebust, Holm, Maehlum, Engebretsen, & Bahr, 2003; von Porat et al., 2004). A review by Oiestad and colleagues reported that the prevalence of knee osteoarthritis after isolated ACL injury was as high as 13%, with higher rates (21% to 48%) in patients with medial collateral ligament or meniscal injuries (Oiestad, Engebretsen, Storheim, & Risberg, 2009). Therapists should counsel patients that the risk of developing knee osteoarthritis is similar whether they have surgery or choose nonoperative management of an ACL injury.

RISK FACTORS

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n the past 15 years, a greater emphasis has been placed on determining the risk of an ACL injury and recognizing the factors that may increase that risk. Identifying the risk factors that contribute to an initial or second ACL injury allows clinicians to develop risk profiles, screen individuals to identify those at the greatest risk for injury, and develop targeted interventional strategies to potentially reduce the risk of injury (Cameron, 2010). Risk factors may be categorized as nonmodifiable or modifiable (Table 1). Although nonmodifiable risk factors such as female sex, narrow femoral notch width, or increased joint laxity cannot be altered, their identification does permit clinicians to counsel athletes on the inherent risk of injury, thus enabling them to make informed decisions regarding sports participation. Female athletes have a substantially greater rate of injury compared to their male counterparts (Arendt & Dick, 1995). Other risk factors for women are joint laxity, knee recurvatum, increased posterior tibial slope, and hormonal changes (Griffin et al., 2006).


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The identification of modifiable factors, such as neuromuscular control, biomechanics, muscle strength, and movement patterns, allows physical therapists and physical therapist assistants to tailor rehabilitations to lower the risk of an ACL injury. Neuromuscular imbalances in the lower extremity have been associated with ACL injury mechanisms during landing from a jump. Four underlying neuromuscular factors have been identified: ligament dominance, quadriceps dominance, leg dominance, and trunk dominance (Hewett, Torg, & Boden, 2009; Myer, Ford, Khoury, Succop, & Hewett, 2010). Ligament dominance results from the insufficient absorption of the ground reaction forces by the surrounding musculature, causing the knee joint and ligamentous structures to absorb the high force levels. The bony architecture and static stabilizers of the knee must mitigate these high ground reaction forces over a short time period. Quadriceps dominance results from repeated use of the quadriceps muscles to stabilize the knee joint, thereby reducing the amount of knee flexion during activities such as landing from a jump. This action causes an anterior shear force to the tibia and ACL. Leg dominance results from an individual’s continual favoring of one leg over the other, often due to underlying limbtolimb asymmetries. These limbtolimb asymmetries can increase the risk of future ACL injury (Hewett et al., 2005). Finally, trunk dominance is the lack of precision trunk control. Neuromuscular control and instability in the trunk may create increased lateral positioning of the trunk during cutting or landing. Increased lateral positioning can result in increased loads at the knee. Lack of https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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precision trunk control contributes to the increased risk of ACL injuries (Zazulak, Hewett, Reeves, Goldberg, & Cholewicki, 2007). Multiple training programs that aim at reducing ACL injury risk by improving dynamic neuromuscular control through conditioning have been proposed (Hewett, Ford, Hoogenboom, & Myer, 2010; Steffen et al., 2013). For example, Hewett and colleagues have developed a training program to address each of the four underlying neuromuscular factors in an attempt to reduce the risk of initial ACL injury (Hewett et al., 2010). Other modifiable neuromuscular factors are predictive of a second injury once athletes have returned to their sporting activities after ACL reconstruction. Paterno and colleagues found that 23.2% of patients sustained a second ACL injury after ACL reconstruction. These researchers were able to identify factors that place athletes at risk for a retear of the ACL graft or the contra lateral ACL (Paterno et al., 2010). Neuromuscular control deficits of the hip external rotators, force absorption asymmetries by the quadriceps muscles, and involved limb singlelegged balance deficits were able to predict second ACL injury risk with a high degree of sensitivity (92%) and specificity (88%). Developing targeted interventions to address these abnormal and altered asymmetries will allow physical therapists to ensure a safer return to sports.

EXAMINATION Demographics Patient demographics have important implications for functional outcomes following ACL reconstruction. Patients with a bodymass index (BMI) greater than 30 kg/m2 have decreased odds of success following ACL injury, as do those with a history of smoking (Ahldén et al., 2012; Kowalchuk, Harner, Fu, & Irrgang, 2009; Uhorchak et al., 2003). It is also important to consider the age and sex of the patient because these factors may affect the course and outcome of treatment. The average age of those who choose to undergo reconstructive surgery is 23 (Magnussen et al., 2010). However, age has been shown to have a weak relationship with scores on selfreported functional measures following surgery (Möller, Weidenhielm, & Werner, 2009). Middleaged adults are more likely to demonstrate dynamic knee instability following ACL injury (Hurd et al., 2008b). Females have an increased risk of ACL injury, with 6 to 8 times greater incidence compared to their male counterparts (Hughes & Watkins, 2006; Mihata, Beutler, & Boden, 2006). Females are also 16 times more likely to reinjure the same ACL following reconstruction (Paterno, Rauh, Schmitt, Ford, & Hewett, 2012). Many possible causes for this gender disparity have been reported, including differences in neuromuscular control, knee laxity, lower limb flexibility and strength, jumping technique, hormone levels, and lower extremity anatomy and biomechanics, including a greater Qangle and smaller inter condylar notch often present in women (Uhorchak et al., 2003; Wild, Steele, & Munro, 2012). However, the exact mechanisms are not fully understood. In addition to higher risk of ACL injury, https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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poor dynamic knee stability is also more common in females than males following ACL injury, which can lead to inferior patient outcomes (Hurd et al., 2008b). Finally, the patient’s previous activity levels, including sports participation or occupation, can be useful in developing an individualized and effective plan of care.

History and Subjective Examination Important components of initial documentation include a complete patient history, with the length of time from initial injury or onset of symptoms, mechanism of injury, frequency and duration of symptoms, pain patterns, presence of any mechanical symptoms (e.g., recurrent clicking or catching), previous history of lower extremity injuries, current use of medications, and reports of any previous diagnostic testing or imaging. Patients can often recall the exact time and activity when injury occurred, usually reporting a “pop” with associated pain and effusion, indicating possible ligamentous injury. However, some patients may deny any pain or swelling but rather may report an increasing frequency of knee instability and giving way. Most patients will present with complaints of pain following injury (Magnussen et al., 2010; Thomee et al., 2007), although the levels are highly variable depending on the extent of joint effusion and concomitant injuries. Patients report that pain levels influence their current level of knee function regardless of the phase of rehabilitation, especially when pain levels are high (Chmielewski et al., 2008). For patients undergoing ACL reconstruction, pain levels are typically highest immediately after surgery (Brewer et al., 2007). Different origins of knee pain may be present, each of which may alter patient progress through rehabilitation. Because anterior knee pain may come from several paingenerating tissues, it is essential to determine the source early in order to implement appropriate treatment techniques, given the relationship of pain to outcomes. For example, Heijne and colleagues found that anterior knee pain was an important predictor in patientreported outcomes 12 months after ACL reconstruction (Heijne, Ang, & Werner, 2009). Patients should employ a visual analogue or numeric pain rating scale to assess their pain, both at rest and with activity levels. Worst and least pain ratings over the previous days or weeks may also be measured. Patients often report knee joint effusion shortly after initial ACL injury. Joint effusion is an excessive accumulation of fluid within a joint capsule, indicating inflammation or irritation (Sturgill, SnyderMackler, Manal, & Axe, 2009). Effusion is different from swelling and edema, which refer to increased fluid within the soft tissues outside of the joint capsule. Hemarthrosis causes acute joint effusion, while effusion developing 8 to 24 hours following injury results from synovial swelling (Magee, 2002). Knowing the time of onset of knee effusion may provide valuable information in the diagnostic process. For example, unlike ACL injuries, meniscal injuries often do not demonstrate immediate bloody effusion, due to the mostly avascular nature of the menisci (Magee, 2002). Knee joint effusion levels may reflect the irritability of the joint, and can increase following physical activity, https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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especially when knee instability is present. Monitoring joint effusion is thus useful in determining the correct progression of therapeutic exercises and activity, and can be an indicator of patient progress (Sturgill et al., 2009). The loss of static and dynamic stability following ACL injury may lead to patient reports of knee instability with activity levels as simple as walking. When ligamentous support is diminished following ACL injury, dynamic knee stability must be achieved via neuromuscular adaptations. These neuromuscular adaptation patterns, however, can differ among individuals (Hurd et al., 2008a). Patients may report episodes of giving way (dynamic knee instability), defined as buckling or subluxation of the tibiofemoral joint since the time of initial ACL injury, resulting in further pain and joint effusion (Fitzgerald et al., 2000a; Fitzgerald, Axe, & SnyderMackler, 2000b, 2000c). These episodes of knee joint instability may present as the primary contributor to decreased functional activity levels, and persistent subjective knee instability has a negative influence on outcomes, whether nonoperative or operative treatment is obtained (Meunier, Odensten, & Good, 2007). Knee instability is a common reason patients cite in their decision to undergo surgical reconstruction.

Physical Examination Observation and Palpation In addition to a thorough patient history, a physical examination that includes observation and palpation can provide further information for formulating an accurate diagnosis. Posture should be assessed in both the seated and standing positions, and any deviations from normal posture that could affect the function of the knee should be noted, including excessive thoracic kyphosis or lumbar lordosis, pelvic obliquities, femoral or tibial torsion, genu valgum or varum, genu recurvatum, abnormal patellar positioning, and excessive foot pronation. Posture should likewise be assessed during movement such as squatting or stair climbing to determine if these deviations are present during dynamic activities, or if additional postural deviations are presented that were not observed during static postural assessment. For example, the patella may be positioned normally in a static standing position, but normal superior migration of the patella may be decreased during an activity involving knee flexion, which could indicate possible patellofemoral joint hypomobility. Palpation and inspection of the knee joint and surrounding structures can further assist in the diagnostic process. Most structures can be easily palpated with the knee in an extended position, although the medial and joint lines are best palpated with the knee flexed to 90° (Magee, 2002). Point tenderness should be documented, along with any erythema, swelling, or bruising. While not a common sequela of acute ACL injury, superficial bruising may be indicative of extraarticular ligament or tendon damage, especially to the medial collateral ligament. Inspection of any quadriceps atrophy is important because quadriceps weakness can develop quickly following ACL injury (Williams, Buchanan, Barrance, Axe, & SnyderMackler, 2005). Quadriceps atrophy may be more easily assessed during a https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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quadriceps set, which also allows for assessment of quality of quadriceps activation and control. Patellar joint mobility should be assessed in all directions, as patellofemoral joint hypomobility can affect knee flexion and extension range of motion (ROM). If previous scars are present, assessing scar tissue can provide information on the patient’s typical healing processes. Gait Patients will often demonstrate an antalgic gait pattern following ACL injury. A joint stiffening strategy consisting of decreased peak knee flexion and increased cocontraction of the quadriceps and hamstrings during stance phase may be present (Chmielewski, Hurd, Rudolph, Axe, & Snyder Mackler, 2005). Decreased stance time on the involved limb and knee extension at heel strike may also develop secondary to feelings of knee instability and pain. Increased hip joint excursion, but with decreased peak hip flexion of the involved limb compared to the uninvolved limb, may be observed, and is more likely to be present in women than in men (Di Stasi & SnyderMackler, 2012).

Clinical Tests Quadriceps Strength Quadriceps strength deficits are common and significant following ACL injuries, often occurring rapidly after injury (Williams et al., 2005). Quadriceps strength can be objectively measured using handheld dynamometry; however, accuracy of testing is low if the examiner is unable to provide greater resistance than the maximal force of the patient’s quadriceps muscle. Manual muscle testing of knee flexors and extensors can be performed to assess for possible weakness or pain secondary to the external resistance applied, but only when compared to the uninvolved limb. Assessing extensor lag during a straight leg raise can be an easy clinical measure of functional quadriceps strength; absence of an extensor lag leads to better postoperative outcomes (Shelbourne, Freeman, & Gray, 2012). Isokinetic dynamometry may be used to measure quadriceps strength following ACL injury. However, this method is generally not preferred at slower speeds in an ACLdeficient knee immediately following acute injury because of the large shearing forces experienced by the knee joint in the terminal ranges of knee extension. Isokinetic dynamometry is, however, a safe and reliable method of testing quadriceps strength in the later stages of rehabilitation following ACL reconstruction (Brosky, Nitz, Malone, Caborn, & Rayens, 1999). Another technique used by clinicians to measure quadriceps strength is the burst superimposition technique during a maximal voluntary isometric contraction (MVIC) (SnyderMackler, Delitto, Stralka, & Bailey, 1994). During testing, a burst superimposition of electrical stimulation is delivered to the quadriceps muscle while the patient is completing a quadriceps MVIC. Quadriceps muscle activation is then calculated as the ratio of force https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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produced during MVIC to the force produced with addition of the electrical stimulation, which can be used as a measure of arthrogenic muscle inhibition or the inability to fully activate a muscle due to structural changes in a joint (Lynch, Logerstedt, Axe, & SnyderMackler, 2012). Testing is completed on each limb until 95% quadriceps activation is achieved, activation levels plateau, or the patient fatigues. After completing testing on each limb, a quadriceps index (QI) can be calculated as the quotient of the involved limb to the uninvolved limb multiplied by 100. The QI provides information on the strength of the quadriceps of the involved limb in comparison to the contralateral limb. The burst superimposition technique is superior to handheld dynamometry because the patient completes an MVIC into a stationary structure that records quadriceps muscle force generation; thus, the assessment is not dependent on the ability of the examiner to provide sufficient resistant force for testing. Also, unlike handheld dynamometry, the burst superimposition technique allows for measurement of quadriceps muscle activation, providing information on the patient’s ability to volitionally activate the quadriceps and whether progression of activity can be recommended. Arthrogenic muscle inhibition, measured by decreased quadriceps muscle activation (Lynch et al., 2012), can limit effective rehabilitation following knee injuries and thus delay return to previous activity levels (Rice & McNair, 2010). Quadriceps activation failure is common following ACL injuries and reconstruction, and is often observed bilaterally (Chmielewski, Stackhouse, Axe, & SnyderMackler, 2004; Hart, Pietrosimone, Hertel, & Ingersoll, 2010; SnyderMackler, Delitto, Bailey, & Stralka, 1995; Williams et al., 2005). For patients who choose to undergo ACL reconstruction, it is essential to regain preoperative quadriceps muscle strength following injury. Preoperative quadriceps strength deficits predict poor quadriceps strength and low selfreported function after surgery (Eitzen, Holm, & Risberg, 2009; Logerstedt, Lynch, Axe, & SnyderMackler, 2012a). Eitzen and colleagues suggest that ACL reconstruction should not be performed until the QI is at least 80%. Quadriceps strength is of equal importance to patients who choose nonoperative treatment because it may help prevent early onset osteoarthritis (OA) (Ageberg et al., 2008). Whichever technique is used to measure strength, it is important to consider the validity of the muscle strength measurement, because knee pain during testing may decrease the force production capability of the muscle being tested and provide inaccurate information regarding quadriceps muscle strength. Range of Motion Acute loss of knee flexion and/or extension ROM may be present secondary to increased pain and joint effusion after ACL injury and ACL reconstruction. Regaining full knee ROM following ACL injury is crucial because chronic loss of as little as 3° of extension ROM can lead to significant impact on both subjective and objective patient outcomes (Shelbourne & Gray, 2009). Full knee joint ROM can be difficult to define secondary to large population variance. Magee describes full knee flexion as equal to 135° and knee extension as equal to 0°; however, https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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hyperextension up to 15° is recognized as common, especially in women (Magee, 2002). Shelbourne and colleagues recommend comparing the involved knee joint ROM to the uninvolved knee in order to determine “normal” motion for each individualized patient case (Shelbourne, Freeman, & Gray, 2012). The International Knee Documentation Committee (IKDC) criteria for normal knee ROM are knee extension within 2° and knee flexion within 5° of the contralateral knee (AOSSM, 2009). Knee ROM is important to monitor because a change can lead to altered biomechanics with functional tasks and limited activity levels (Millett, Wickiewicz, & Warren, 2001). The incidence of ROM loss after ACL reconstruction is reported to be between 2% and 11% (Millett et al., 2001). For patients planning to undergo ACL reconstruction, ROM measurements using goniometry are useful for determining the timing of surgery. The use of goniometry for measuring ROM is highly valid and reliable both within and between examiners (Phisitkul, James, Wolf, & Amendola, 2006). Full preoperative knee extension ROM has been linked to better postsurgical outcomes (Shelbourne, Wilckens, Mollabashy, & DeCarlo, 1991). Mauro and colleagues reported that 25% of patients had knee extension deficits one month after ACL reconstruction, and these deficits were associated with preoperative knee extension range of motion, time from injury to surgery, and use of autograft (Mauro, Irrgang, Williams, & Harner, 2008). Chronic loss of ROM can lead to increased risk of future osteoarthritis at the knee joint (Shelbourne, Freeman, & Gray, 2012). Knee Joint Effusion Joint effusion is an elevated level of fluid within the joint capsule that is often present following ACL injury and reconstruction and contributes to impairments in ROM and to pain. It had been thought that knee joint effusion led to inhibition of the quadriceps muscle (PalmieriSmith, Kreinbrink, AshtonMiller, & Wojtys, 2007; Spencer, Hayes, & Alexander, 1984); however, recent literature suggests that quadriceps activation failure following ACL injury may not be the result of knee joint effusion alone (Lynch et al., 2012). Acute knee joint effusion is also present following ACL reconstruction, and may become chronic in nature despite use of an appropriate effusion management program. Knee joint effusion is important to assess through the nonoperative, preoperative, and postoperative time periods. Knee joint effusion is usually based on clinical observation, and accurately assessing the volume of effusion can be difficult (Wright & Luhmann, 1998). The fluctuation test and patellar tap test have either positive or negative grades, but they lack a quantified scaling system and are unreliable (Fritz, Delitto, Erhard, & Roman, 1998). The fluctuation test is performed by placing one palm on the suprapatellar pouch and the other palm on the anterior knee and then pressing down with palms in an alternating pattern. Fluctuation of fluid under the examiner’s hands indicates a positive test (Magee, 2002). The patellar tap test is performed with the patient’s knee extended or flexed to discomfort, followed by slight pressure over the patella. A positive test is present when the examiner feels floating https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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of the patella (Magee, 2002). Circumferential measurements using a tape measure can assess joint swelling but may reflect increases in girth beyond those caused only by knee joint effusion. Another method used to measure knee joint effusion is the modified stroke test, which has been shown to be reliable in a clinical setting (Sturgill et al., 2009). The test quantifies knee joint effusion using a 5point scale, and begins by the examiner stroking any fluid upward at the medial tibiofemoral joint line 2 or 3 times. If the swelling does not immediately return, the examiner then strokes downward along the distal lateral thigh and observes for any return of fluid at the medial sulcus. The test is graded as follows: Grade 0: No wave was produced with the downward stroke Grade Trace: Small wave of fluid returns at the medial sulcus with the downward stroke Grade 1+: Larger return wave of fluid produced at the medial knee Grade 2+: Swelling returns without the downward stroke Grade 3+: Inability to move the effusion out of the medial sulcus Knee Joint Laxity Tibiofemoral joint laxity is commonly tested via anterior tibial translation when an ACL injury is suspected. There are several special tests and tools for assessing tibiofemoral joint laxity, including the anterior drawer test, Lachman test, pivot shift test, and arthrometry. The anterior drawer test is performed with the patient lying supine with 90° of knee flexion and 45° of hip flexion. An anterior translation force is applied to the proximal tibia while the foot is stabilized, with a soft end feel and increased anterior tibial translatory excursion indicating a positive test (Magee, 2002). The anterior drawer test is considered abnormal with a 6 to 10 mm difference of anterior tibial translation compared to the uninvolved tibiofemoral joint and severely abnormal with greater than 10 mm difference according to IKDC 2000 criteria (AOSSM, 2009). The Lachman test is performed while the patient lies supine with the knee flexed 20° to 30°. The examiner stabilizes the distal femur with one hand while providing an anterior force to the proximal tibia with the other hand (Magee, 2002). A soft end feel compared to the contralateral side constitutes a positive test, and the same grading system used for the anterior drawer test is also applied to the Lachman test (AOSSM, 2009). The pivot shift test is performed while the patient is in the supine position with the knee started in an extended position. The examiner internally rotates the tibia with one hand at the ankle while providing a valgus force with the other hand at the proximal tibia while simultaneously flexing the knee. A positive test is present when anterolateral tibial subluxation is reduced as the knee moves into increased flexion (Benjaminse, Gokeler, & van der Schans, 2006). The pivot shift test is graded between limbs as equal, glide (+), clunk (++), or gross (+++) (AOSSM, 2009). https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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The Lachman test is the most accurate for detecting ACL tears, with a sensitivity of 85% and specificity of 94% (Benjaminse et al., 2006). The pivot shift test demonstrates very high specificity at 98% but poor sensitivity at 24% (Benjaminse et al., 2006). The anterior drawer test can be useful in chronic conditions, with a sensitivity of 92% and a specificity of 91%, but is not as accurate in acute conditions (Benjaminse et al., 2006). When acute ACL injury is suspected, Benjaminse and colleagues recommend performing the Lachman test along with the pivot shift test to assist in diagnosis (Benjaminse et al., 2006). In addition to using special tests during clinical assessment of tibiofemoral joint laxity, instrumentation may also be used as an adjunct in confirming ACL injuries. The KT1000 arthrometer is a device that has been validated to measure the amount of anterior tibial translation relative to the femur (Pugh, Mascarenhas, Arneja, Chin, & Leith, 2009). A review by Arneja and Leith indicates that a diagnostic test indicating ACL involvement is positive when 2 to 3 millimeters difference in maximal tibial anterior translation between involved and uninvolved limbs is present. The authors do not recommend testing the involved limb only (Arneja & Leith, 2009). While KT1000 arthrometry may be useful in developing a diagnosis of ACL tear, there is only a weak correlation between knee joint laxity and knee function following ACL reconstruction (Ross, Irrgang, Denegar, McCloy, & Unangst, 2002). Neuromuscular Control Neuromuscular adaptations are present following both ACL injury and reconstruction. These adaptations can result from affected mechanoreceptors in the ACL and joint capsule which influence somatosensation, muscle activation, muscle strength and atrophy, balance, and gait biomechanics (Ingersoll, Grindstaff, Pietrosimone, & Hart, 2008). Afferent information sent to the central nervous system can be affected by some of these neuromuscular changes, sometimes leading to impairments in bilateral lower extremities, as seen in some patients with bilateral quadriceps activation failure (Ingersoll et al., 2008). Changes in neuro muscular control patterns may lead to chronic biomechanical changes at the lower extremities, increasing the risk of future osteoarthritis at the involved knee joint (Hurd & SnyderMackler, 2007; Ingersoll et al., 2008; Rudolph, Axe, Buchanan, Scholz, & SnyderMackler, 2001). Although many neuromuscular adaptations affecting the knee joint can be detected only in a laboratory setting, examination of balance and muscle activation patterns can be used to clinically assess neuromuscular control following ACL injury and reconstruction. Differences in singleleg balance tasks, with eyes open and with eyes closed, have been detected in the involved limb following ACL injury compared to controls; however, differences may not be present between limbs (Lysholm, Ledin, Odkvist, & Good, 1998). Abnormal muscle activation patterns, such as increased activation of the hamstrings, may be seen, indicating cocontraction strategies to achieve knee stabilization (O’Connell, George, & Stock, 1998). When assessing balance, it is important to include perturbations rather than https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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static challenges only, because they may better represent demands required during different activity levels (O’Connell et al., 1998). Reaction times to perturbations may be greater in the involved limb than in the uninvolved limb (Lysholm et al., 1998). The Star Excursion Balance Test is performed by standing on one leg and reaching maximally with the other leg in eight different directions. During single leg activities on the involved limb, this test has demonstrated deficiencies in dynamic postural control following ACL injuries in four of the directions tested (anterior, lateral, posteromedial, and medial). However, caution is needed; differences were also present in the medial and lateral directions between the uninvolved limb and controls (Herrington, Hatcher, Hatcher, & McNicholas, 2009). Neuromuscular training based on findings during examination should be integrated into the patient’s rehabilitation program, as it leads to improvements in limb symmetry prior to and after ACL reconstruction (Hartigan, Axe, & SnyderMackler, 2009).

Functional Testing Biomechanical limbtolimb asymmetries during gait are present following ACL injury and reconstruction (Di Stasi, Logerstedt, Gardinier, & SnyderMackler, 2013; Hurd & SnyderMackler, 2007; Ingersoll et al., 2008; Rudolph et al., 2001; Rudolph, Eastlack, Axe, & SnyderMackler, 1998), and these abnormalities become exaggerated with the increased demands of jogging and running (Ingersoll et al., 2008). Abnormal movement patterns, which may limit performance during stair ascent and descent, lateral step up tasks, and vertical jump tasks, are also present and important to examine (Ingersoll et al., 2008). Following ACL rupture, multiple episodes of giving way may occur during activities of daily living (ADLs) (Daniel et al., 1994; Eastlack, Axe, & Snyder Mackler, 1999). Recurring episodes of giving way place patients at increased risk of further knee joint damage, and help predict whether patients may succeed with nonoperative treatment (Fitzgerald et al., 2000a). Singlelegged hop tests are often used as a measure of activity limitations following ACL injury and reconstruction (Grindem, Eitzen, Moksnes, SnyderMackler, & Risberg, 2012; Logerstedt, Grindem, et al., 2012; Logerstedt, Lynch, Axe, & SnyderMackler, 2012b; Noyes, Barber, & Mangine, 1991; Reid, Birmingham, Stratford, Alcock, & Giffin, 2007), and can be used to predict dynamic knee stability (Fitzgerald, Lephart, Hwang, & Wainner, 2001; Grindem et al., 2011; Logerstedt, Grindem, et al., 2012). Although preoperative singlelegged hop tests cannot predict postoperative outcomes, testing at 6 months following ACL reconstruction is effective at predicting selfreported knee function at 1 year following ACL reconstruction (Logerstedt, Grindem, et al., 2012). Singlelegged hop tests can also differentiate between patients who are able to return to previous activity levels following ACL injury and reconstruction and those unable to do so (Ardern et al., 2011b; Fitzgerald et al., 2000a). The most common singlelegged hop tests are a series of four hops, including a single hop for distance (single hop), crossover hop for distance (crossover hop), triple hop for distance (triple hop), and 6meter timed hop (6m timed hop) (Barber, Noyes, Mangine, McCloskey, & Hartman, 1990; https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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Daniel et al., 1982; Noyes et al., 1991) (Figure 2). These tests can be used to assess a combination of muscle strength, neuro muscular control, confidence in the injured limb, and ability to complete sportspecific activities (Reid et al., 2007). The singlelegged hop tests are completed along a 6 meter strip on the floor 15 cm wide, with each test completed 2 times for each leg. For the single hop, the patient stands on the leg to be tested and hops as far as possible, landing on the same leg. The crossover hop is completed by the patient hopping three consecutive times on the same leg, alternately crossing over the 15cm strip on each hop with total distance measured. For the triple hop, the patient completes three consecutive hops on the same leg as far as possible in a linear direction, with total distance measured. The single hop, crossover hop, and triple hop must be completed with a controlled landing on the leg being tested without additional hops or assistance of the contralateral leg to achieve balance, or the trial is redone. The 6m timed hop is completed by the patient hopping on one leg as fast as possible along the 6meter distance. Using a stopwatch, the examiner measures the time from when the patient’s heel leaves the ground to the time the 6meter mark is reached. Each hop test is completed on the uninvolved limb first, with 2 practice trials of each hop test completed prior to the 2 measured trials to ensure understanding of the task and decrease anxiety about hopping on the injured limb. The score is assessed by calculating the average of the 2 measured trials. Hops are completed on each leg in order to calculate interlimb differences. The single hop, crossover hop, and triple hop are calculated as a ratio of the involved limb’s mean distance over the uninvolved limb’s mean distance, multiplied by 100, while the timed hop is calculated as a ratio of the uninvolved limb’s mean time over the involved limb’s mean time, multiplied by 100. All 4 singlelegged hop tests are valid and reliable (Reid et al., 2007; Ross, Langford, & Whelan, 2002). Minimal detectable change indexes after ACL reconstruction have been reported that enable clinicians to assess whether hop scores calculated at 2 different time points likely represent a true change in patient function or whether they may be due to measurement error. These are 8.09% for the single hop 12.25% for the crossover hop 10.02% for the triple hop 12.96% for the 6m timed hop (Reid et al., 2007; Ross, Langford, et al., 2002).


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FIGURE 2: SINGLELEGGED HOP TESTS

To avoid risk of further injury, singlelegged hop tests should not be completed if pain is present during inplace unilateral hopping, QI is less than 70% during preoperative or nonoperative rehabilitation, QI is less than 80% during postoperative rehabilitation, the patient is less than 12 weeks from the time of ACL reconstruction, or the modified stroke test grade of effusion is greater than a trace. Completion of singlelegged hop tests allows determination of limbtolimb differences in function, allows assessment of patient progress throughout rehabilitation, and provides useful information to direct patient intervention (Myer et al., 2010; Paterno, Myer, Ford, & Hewett, 2004).

Participation Restrictions Following ACL injury, many patients demonstrate decreased activity levels (Daniel et al., 1994; Fitzgerald et al., 2000a; Grindem et al., 2012), and for patients undergoing ACL reconstruction, activity limitations often continue following surgery (Hartigan et al., 2010; Logerstedt, Lynch, et al., 2012b). Factors affecting activity level after initial ACL injury include perceived knee pain, reduced knee ROM, decreased quadriceps strength, increased knee joint effusion, knee joint instability, patientperceived https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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decreased knee function, and fear of reinjury. Many patients decrease participation and intensity of activity levels to avoid episodes of giving way and further impairments, including pain and effusion (Eastlack et al., 1999; McCullough et al., 2012); however, some individuals demonstrate the ability to maintain their preinjury activity levels without instability (Daniel et al., 1994; Eastlack et al., 1999; Hurd et al., 2008a; SnyderMackler, Fitzgerald, Bartolozzi, & Ciccotti, 1997). Individual assessment of each patient regarding participation restrictions is indicated to develop an individualized plan of care because patients present with varying impairments following ACL injury, concomitant injuries, preinjury activity levels, goals for return to activity levels, and responses to targeted intervention (Fitzgerald et al., 2000a; Hartigan et al., 2010; Hurd et al., 2008a).

PatientReported Outcomes Patientreported outcome measures are an important component in providing effective care following ACL injury and reconstruction because selfreport of current perceived function and activity levels assists in developing functional, patientdirected goals and establishing an individualized plan of care. Patientreported outcome measures can also be used to monitor progress throughout the rehabilitative process. While many patientreported outcome measures exist, including general health questionnaires, kneespecific questionnaires, and activity scales, it is important to understand what each measure is evaluating in order to choose the most appropriate and relevant measures for a patient following ACL injury. General Health Questionnaires The Medical Outcomes Study Short Form36 (SF36) is a general measure of health status used for both acute and chronic conditions (Shapiro, Richmond, Rockett, McGrath, & Donaldson, 1996). It measures eight dimensions of health, including measures of physical function, role limitations due to physical problems, bodily pain, general health, vitality, social function, role limitations due to emotional problems, and mental health (Irrgang et al., 2001). Scores from the eight categories are combined to produce a physical and mental component, and the SF36 is valid and reliable across its scales in a variety of diverse patient populations (McHorney, Ware, Lu, & Sherbourne, 1994). Within the ACLinjured population, the SF36 can discriminate between acute and chronic injuries, as patients with acute ACL injuries score lower than those with chronic injuries, while both groups score significantly lower than norms for the general population (Shapiro et al., 1996). By assessing the general health of a patient, the SF36 provides information on factors beyond impaired knee function that may impact patient response to rehabilitation. KneeSpecific Questionnaires


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The International Knee Documentation Committee Subjective Knee Form (IKDC 2000) is a kneespecific measure of symptoms, function, and sports activities used to assess patientperceived function for a variety of knee conditions scored on a scale from 0 to 100 calculated from 18 items, with higher scores indicating higher selfreported levels of knee function (AOSSM, 2009). The IKDC 2000 can be used to categorize patients via their current physical activity levels and assist with determining knee function by comparing current levels to preinjury levels, with level I representing sports that involve cutting and pivoting (e.g., soccer, basketball, and football), level II representing activities with lateral movements but less jumping (e.g., skiing, hockey, racquet sports, and manual labor occupations), level III representing light activities (e.g., running, low impact aerobics, and weight lifting), and level IV representing sedentary activities (e.g., housework and activities of daily living; Daniel et al., 1994; Hefti, Muller, Jakob, & Staubli, 1993).The IKDC 2000 is reliable and is positively correlated to the physical component of the SF36 (Irrgang et al., 2001). It is also responsive and able to detect clinically meaningful change, with a change score of 11.5 indicating improved selfperceived knee function (Irrgang et al., 2006). The Knee Outcome SurveyActivities of Daily Living Scale (KOSADLS) is a patientreported measure of impairments and functional limitations experienced during activities of daily living within a population possessing a wide variety of knee pathologies and impairments (Irrgang, SnyderMackler, Wainner, Fu, & Harner, 1998). It is reliable and uses an ordinal scaling system, with the overall score out of a possible 70 points represented as a percentage (Irrgang et al., 1998). A score of 100% represents the absence of knee impairments or functional limitations with activities of daily living (Irrgang et al., 1998). The Knee Injury and Osteoarthritis Outcome Score (KOOS) consists of five subscales assessing patient symptoms, complaints of pain, function in daily life, function during sports and recreational activities, and kneerelated quality of life designed for patients with ACL injury, meniscus injury, or post traumatic knee osteoarthritis (Roos, Roos, Lohmander, Ekdahl, & Beynnon, 1998). The score for each subscale ranges from 0 to 100, with increased scores indicating higher subjective knee function (Roos et al., 1998). All subscales of the KOOS are reliable within the population for which they were developed (Roos et al., 1998). Higher correlations are seen between the KOOSADL and KOOS Sport and Recreation Function subscales with the physical function scales of the SF36, compared to mental health components of the SF36 (Roos et al., 1998). Although the usefulness of each of the subscales – except for Sport and Recreation Function – has been questioned for the acute ACL injury and ACLreconstructed populations (van Meer et al., 2013), the measure is widely used in these populations (Ahldén et al., 2012; Frobell et al., 2013; Maletis, Granan, Inacio, Funahashi, & Engebretsen, 2011; Wright et al., 2011). The Global Rating Scale of Perceived Function (GRS) consists of a single question that evaluates a patient’s current overall subjective knee function on a scale from 0 to 100. Zero represents the inability to perform any activity, and 100 indicates the level of knee function prior to injury (Logerstedt, Lynch, et al., 2012b). An analogue GRS was found to be https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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reliable in the ACL population, demonstrating good repeatability, with a minimal detectable change of 6.49 representing true change in patient reported function (Hopper et al., 2002). Psychological Questionnaires The ACLReturn to Sport after Injury (ACLRSI) scale is a patient reported measure that assesses emotions, confidence in performance, and risk appraisal associated with returntosport activities following ACL reconstruction (Webster, Feller, & Lambros, 2008). The ACLRSI score ranges from 0 to 100, representing an average of the scores on 12 questions, with lower scores indicating more negative psychological responses in regard to returning to sport (Webster et al., 2008). Scores on the ACLRSI have been shown to increase with time after ACL reconstruction, with a minimal detectable change of 19, and patients who have returned to preinjury sports activity levels score significantly higher on the ACLRSI (Kvist et al., 2012; Langford, Webster, & Feller, 2009). The ACLRSI has been shown to be reliable and valid, as patients with increased ACLRSI scores also score higher on all the KOOS subscales. Another scale that assesses fear of movement and reinjury from involvement in physical activity is a modified version of the Tampa Scale for Kinesiophobia known as the TSK11. (Please note, however, that this scale is not specific to patients with knee pathology.) The TSK11 includes 11 items and has a range of possible scores from 11 to 44. Lower scores indicate lower levels of fear of movement and reinjury. The scale is reliable and demonstrates both construct and predictive validity (Woby, Roach, Urmston, & Watson, 2005). TSK11 scores have been shown to be elevated following ACL reconstruction, and relate to lower selfreport of function and rate of return to preinjury activity levels (Chmielewski et al., 2008; Kvist, Ek, Sporrstedt, & Good, 2005; Lentz et al., 2009). While scores on the TSK11 decrease with time following ACL reconstruction, they are associated with knee function only after 6 months following surgery, corresponding to the time frame when return to sports activities is often allowed (BarberWestin & Noyes, 2011; Chmielewski et al., 2008). Lower scores on the TSK11 have been associated with increased ACLRSI scores (Kvist et al., 2012). A reduction of four points on the TSK11 maximizes the likelihood of correctly identifying patients who have reduced their fear of movement and reinjury (Woby et al., 2005). The Knee SelfEfficacy Scale (KSES) is a reliable instrument consisting of 22 items designed to measure how certain respondents are that they can perform various physical activities (Thomee et al., 2006). KSES scores are generally higher in males, individuals who have higher baseline physical activity levels, and younger individuals (Thomee et al., 2007). Improvements in selfefficacy over the first 12 weeks following ACL reconstruction have been associated with improvements in pain and function during that same time frame (Chmielewski et al., 2011). Patients’ scores for selfefficacy of knee function preoperatively have also been shown to predict symptoms, muscle function, and return to acceptable levels of physical activity 1 year after ACL reconstruction (Thomee et al., 2008). https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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Activity Scales Beyond patient selfreport of general health and kneespecific impairment and function, activity scales provide further information regarding intensity and frequency of patient activity levels. The IKDC 2000 activity scale, as previously described, can be used to categorize patients according to sports or work demands (Daniel et al., 1994; Hefti et al., 1993). The Tegner Activity Level Scale is an 11point grading scale for work and sports activities (Tegner & Lysholm, 1985). The scale rates activity level from 0 (sick leave or disability pension because of knee problems) to 10 (competitive sports such as soccer, football, or rugby at the national or elite level). The scale was initially developed to measure activity following knee ligamentous injury and has been validated for use following ACL injury. The Tegner Scale has demonstrated acceptable testretest reliability (ICC = .80) after ACL reconstruction and is sensitive to change up to 2 years following ACL reconstruction, with a minimally detectable change of 1 indicating true change in patient report (Briggs et al., 2009). The Marx Activity Rating Scale (Marx) is a 4item patientreport questionnaire that assesses the frequency of activities such as running, cutting, decelerating, and pivoting, but is not intended to assess outcomes following intervention or surgery (Marx, Stump, Jones, Wickiewicz, & Warren, 2001). The scale was developed to use in a population with a variety of knee disorders, but is useful in the ACL population to assess whether patients have returned to preinjury activities at previous frequency levels. The Marx Activity Rating Scale is scored from 0 to 16, with a score of 0 indicating completion of the four activity items less than one time per month and 16 indicating completion of the four activity items at least four times per week (Marx et al., 2001). The Marx scale is reliable and inversely correlated with age (Marx et al., 2001). It is important to select an outcome measure according to the construct it measures in relation to what information the therapist is attempting to gather. The IKDC 2000 is a more useful measure of knee impairment and function than the KOOS following ACL injury and reconstruction (van Meer et al., 2013). The ACLRSI may be a more useful tool for measuring psychological influences on return to sport activities than the TSK11 because it was developed specifically in relation to return to sport following ACL injury, whereas the TSK11 was developed to assess painrelated fear of movement and reinjury not specific to the ACL population (Kvist et al., 2012) The SF36 is an important measure to use in assessing a patient’s general health status and the comorbidities that may impact progress through rehabilitation following ACL injury or reconstruction.

DIFFERENTIAL DIAGNOSIS AND CONCOMITANT INJURIES

I

njury to the ACL often occurs concomitantly with damage to other static knee joint structures, and differential diagnosis can be difficult. Meniscus, articular cartilage, and medial collateral ligament (MCL) pathology is common in combination with ACL injuries. Incidence rates of https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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injury to the PCL (1.4%) and lateral collateral ligament (LCL) (2.2%) with ACL injury is low, with these injuries usually resulting from traumatic events involving knee joint dislocation (Fanelli, Orcutt, & Edson, 2005; Majewski et al., 2006). Injury to the ACL, MCL, and medial meniscus is referred to as the “unhappy triad” (O’Donoghue, 1950). Damage to this trio of structures often occurs secondary to the common biomechanical positioning during ACL injuries, with excessive knee valgus and tibial internal rotation, which places increased tension on the MCL; because the MCL is attached to the medial meniscus, it is also at increased risk of injury (Schein et al., 2012).

Medial Collateral Ligament Concomitant medial collateral ligament (MCL) injury (30.3%) is more common than LCL injury (2.2%) with ACL rupture (Majewski et al., 2006). Seventyfour percent of patients who sustain a complete tear to the MCL also sustain an ACL injury (Fetto & Marshall, 1978). MCL injuries are often treated nonoperatively regardless of severity and whether ACL reconstruction is performed. If ACL reconstruction is performed, it is typically postponed until the MCL has had the opportunity to heal, as valgus instability is detrimental to optimal graft healing. Following ACL rupture, patients with grade III MCL injuries treated surgically demonstrate no difference in impairmentbased or functional outcomes from those treated conservatively 2 years following injury (Halinen, Lindahl, Hirvensalo, & Santavirta, 2006). However, if chronic valgus instability is present following standard rehabilitation, surgical repair of the MCL may be warranted (Grant, Tannenbaum, Miller, & Bedi, 2012).

Meniscus Meniscus injuries negatively impact patientreported functional outcomes, with higher rates of knee arthrosis following ACL reconstruction compared to patients without meniscal damage (Cohen et al., 2007; Eitzen et al., 2009). While previous literature has reported that the odds of meniscus injury being present at the time of ACL reconstruction increase as time increases from initial injury (Fok & Yau, 2013; Granan, Bahr, Lie, & Engebretsen, 2009; O’Connor, Laughlin, & Woods, 2005), and the risk of secondary meniscal tear is reduced after ACL reconstruction (Kessler et al., 2008), no differences have been shown in rates of meniscal surgery with ACL reconstruction in patients who chose an early or delayed surgical date (Frobell et al., 2013). It is estimated that 50% to 65% of patients choosing ACL reconstruction demonstrate meniscal tears at the time of surgery (Granan et al., 2009; Magnussen et al., 2010; Majewski et al., 2006). The current most common approach to meniscal injuries in the United States is surgical resection (meniscectomy) during ACL reconstruction, followed by meniscus repair or observation only (Magnussen et al., 2010). However, the frequency of surgical meniscal repair is expected to increase as a result of improving surgical techniques and increasing evidence of higher risk of osteoarthritis following meniscectomy (Noyes & BarberWestin, 2012).


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Articular Cartilage Nearly 50% of ACL injuries also result in damage to the articular cartilage (Magnussen et al., 2010), and patients with articular cartilage lesions have an increased likelihood of meniscal injuries, and vice versa (Fok & Yau, 2013; Granan et al., 2009). For patients who undergo ACL reconstruction, older age and time from injury to surgery increase the odds of having cartilage lesions in the involved knee at the time of surgery (Fok & Yau, 2013; Granan et al., 2009; O’Connor et al., 2005). ACL injuries in combination with articular cartilage damage are associated with complaints of more frequent and intense episodes of pain (Fok & Yau, 2013), along with poorer patientreported outcomes (Kowalchuk et al., 2009). Cartilage debridement (chondroplasty) is the most common surgical technique employed during ACL reconstruction to treat cartilage lesions, but microfracture surgery and observation are also used (Magnussen et al., 2010). Microfracture surgery is a procedure in which small subchondral holes or fractures are created to stimulate cartilage repair (Mithoefer et al., 2005).

Osteoarthritis Patients are at increased risk of knee osteoarthritis following ACL injury, with more than 50% of athletes demonstrating radiographic changes 10 years after surgery (Meuffels et al., 2009). Altered gait biomechanics are a suspected risk factor for the development and progression of knee osteoarthritis in the ACL population (Andriacchi & Mundermann, 2006; Butler, Minick, Ferber, & Underwood, 2009; Webster, McClelland, Palazzolo, Santamaria, & Feller, 2012); however, the exact mechanisms are not yet known. Additionally, there are no differences in the incidence of knee osteoarthritis whether early or delayed ACL reconstruction is chosen (Frobell et al., 2013). Although time from ACL injury to ACL reconstruction does not affect the incidence of osteoarthritis, rates of osteoarthritis are higher in patients following ACL reconstruction in comparison to nonoperative treatment (Kessler et al., 2008), and the risk of knee osteoarthritis is even higher if a meniscectomy is also performed (Claes, Hermie, Verdonk, Bellemans, & Verdonk, 2013).

PSYCHOSOCIAL FACTORS

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ollowing ACL injury, 60% of athletes who have been cleared for return to sport have not returned to full competition at 1 year from surgery, and half of patients are not participating in preinjury activity levels 3 to 4 years following ACL reconstruction (Kvist et al., 2005; Lentz et al., 2012; Webster et al., 2008). Despite these poor results, 90% of patients demonstrate normal or nearnormal knee function when assessed using impairmentbased outcomes within this same time frame (Ardern et al., 2011a). This apparent disparity may result from the influence of psychosocial factors – including fear of reinjury, decreased selfefficacy, and emotional factors – on the ability to return to preinjury activity levels. https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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Fear of movement and reinjury decreases as rehabilitation progresses after surgery, but can continue to impact function during returntoactivity time frames (Chmielewski et al., 2008). Although patient activity levels may decrease for social reasons that include decreased organized sports opportunities, patients who have not returned to preinjury activity levels several years following ACL reconstruction demonstrate greater fear of re injury as measured by the TSK11 (Kvist et al., 2005). In addition to the TSK11, the ACLRSI can be used to measure the emotions, confidence, and risk appraisal associated with return to sport (Webster et al., 2008). It is important to use the ACLRSI to assess psychological preparedness so that appropriate interventions can be implemented to allow for timely return to competitive sport levels (Langford et al., 2009). Selfefficacy is the judgment of one’s potential ability to carry out a task regardless of ability to perform the task or actual performance of the task (Bandura, 1977). Levels of selfefficacy are often low following ACL injury and ACL reconstruction, but improve during the course of rehabilitation. It is important to discuss selfefficacy with patients throughout rehabilitation because poor selfefficacy can negatively affect progress toward achieving rehabilitation goals. Preoperative KSES scores have been found to predict kneerelated quality of life and return to intensity and frequency of preinjury activity levels 1 year following ACL reconstruction (Thomee et al., 2008). Emotional factors such as depression may also affect patient progress following ACL injury; patients with ACL injury score higher on depression scales compared with uninjured controls (Mainwaring, Hutchison, Bisschop, Comper, & Richards, 2010).

MEDICAL DIAGNOSIS

D

iagnosis of an ACL injury can be made with reasonable certainty when a patient presents with clinical findings involving a mechanism of injury of deceleration/acceleration motions with dynamic valgus load, hearing or feeling a “pop” at the time of initial injury, hemarthrosis within 2 hours of initial injury, and a positive Lachman or pivot shift test (Logerstedt, SnyderMackler, Ritter, Axe, & Godges, 2010).

IMAGING

A

rthroscopy is the gold standard in diagnosis of knee pathology. Magnetic resonance imaging (MRI) is also valid in diagnosis of ACL injuries (Galea, Giuffre, Dimmick, Coolican, & Parker, 2009; Kocabey, Tetik, Isbell, Atay, & Johnson, 2004; Madhusudhan, Kumar, Bastawrous, & Sinha, 2008). For diagnosis of ACL tears, the mean sensitivity and specificity of MRI are 78% to 80% and 100%, respectively (Van Dyck et al., 2013). However, clinical examination has been reported to have comparable or better diagnostic accuracy than MRI, especially with ACL injury (Kocabey et al., 2004; Madhusudhan et al., 2008). Therefore, MRI is most useful as an adjunct to physical examination when clinical diagnosis is indefinite. https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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OPERATIVE VERSUS NONOPERATIVE MANAGEMENT

T

he ultimate goal of rehabilitation or surgical management of ACL deficiency is to restore patients’ dynamic knee stability so they can return to their desired activity level. Patients with ACL deficiency may be managed with operative or nonoperative treatment depending on their functional impairments and desired level of activity (Eitzen, Moksnes, SnyderMackler, & Risberg, 2010; Magnussen et al., 2010). In the United States, ACL reconstructive surgery is recommended for individuals presenting with knee instability during simple functional tasks. Surgical intervention is more likely to be recommended for those patients who intend to return to multidirectional activities and to their preinjury activity levels (Beynnon, Johnson, et al., 2005; Eitzen, Moksnes, SnyderMackler, & Risberg, 2010; Hartigan et al., 2010). However, reconstructive surgery does not guarantee returning to preinjury functional level (de Jong et al., 2007; Logerstedt, Lynch, et al., 2012b; Lohmander et al., 2004; von Porat et al., 2004). Over the past decade, a classification system has been developed to provide therapists with a tool to assist in decisionmaking for patient education, management, and rehabilitation interventions.

CLASSIFICATION

B

ecause of the poor association between passive and dynamic knee stability, not all patients who suffer an ACL injury choose to undergo reconstruction. A decisionmaking algorithm was published by Fitzgerald and colleagues in 2000 that allows clinicians to determine which individuals with an ACL rupture have the highest likelihood of returning to a high level of functioning without surgical intervention in the short term (Fitzgerald et al., 2000a). Movement coordination impairments are examined to classify patients as either potential copers or potential noncopers (Fitzgerald et al., 2000a). Potential copers exhibit good dynamic knee stability and compensate well shortly after injury, whereas potential noncopers exhibit poor dynamic knee stability and have less potential for compensation (Hartigan et al., 2009). This classification system is especially useful for clinicians developing rehabilitation programs for patients not undergoing ACL reconstructive surgery and those awaiting ACL surgery (Hurd et al., 2008a). Based on the screening of 93 patients with acute unilateral ACL ruptures, Fitzgerald and colleagues developed a screening examination that is used to classify patients as either potential copers or potential noncopers (Table 2) (Fitzgerald et al., 2000a).


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This screening examination consists of the singlelegged 6m timed hop, selfreported number of episodes of the knee giving way from time of initial injury, KOSADLS score, and the GRS score (Fitzgerald et al., 2000b). Patients are classified as potential copers if they demonstrate a single legged 6m timed hop index of 80% or higher between limbs, no more than one episode of the knee giving way since initial injury, KOSADLS score of 80% or higher, and GRS score of 60% or higher (Fitzgerald et al., 2000b). Individuals who do not meet any one of these criteria are classified as potential noncopers. Descriptive statistics from studies comparing potential copers to potential noncopers demonstrate no differences in quadriceps strength or anterior knee joint laxity outcome measures between groups (Hurd et al., 2008a). Also, a larger percentage of patients are classified as potential noncopers than as potential copers, and these individuals are more likely to be women, middleaged adults, and patients with a noncontact mechanism of ACL injury (Hurd, Axe, & SnyderMackler, 2008c). Patients classified as potential copers may be successful in returning to a short period of preinjury activity levels following nonoperative rehabilitation to finish out an athletic or work season without further meniscus or articular cartilage damage or episodes of the knee giving way (Fitzgerald et al., 2000b; Moksnes, SnyderMackler, & Risberg, 2008). Individuals who are able to return to preinjury sport levels without giving way for at least 1 year are defined as true copers, while true noncopers are those unable to return to preinjury activity levels without multiple episodes of giving way (SnyderMackler et al., 1997).

REHABILITATION CONSIDERATIONS Nonoperative Rehabilitation Programs


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The effectiveness of nonoperative management depends largely on the decisionmaking criteria used for selecting appropriate candidates and the incorporation of perturbation training techniques into the nonoperative rehabilitation program (Fitzgerald et al., 2000a). Regardless of classification, all patients with acute ACL injury are advised to go through 10 sessions of an exercise therapy program (including progressive strengthening training augmented with perturbation training) for a period of 5 to 6 weeks after initial impairments are resolved and before the final decision for either ACL reconstruction or nonoperative management is made (Eitzen, Moksnes, SnyderMackler, & Risberg, 2010). Currently, operative management is recommended for those patients who experience episodes of knee instability during simple activities and who intend to return to activities that involve jumping, cutting, and pivoting movements. The focus of nonoperative treatment is on perturbation training, strengthening, and neuromuscular and agility training. Perturbation Training Rehabilitation programs that include perturbation training, compared to standardized rehabilitation without perturbation training, result in higher rates of return to preinjury activity levels with fewer episodes of giving way for patients classified as potential copers (Fitzgerald et al., 2000c). Perturbation training that includes purposeful destabilization stimuli applied to movable surfaces is incorporated into the rehabilitation program. Perturbation training can consist of 3 techniques: roller board with a stationary platform, roller board, and tilt board (Figure 3). Perturbation training progresses in a similar manner for each technique, with each training session consisting of all 3 techniques. Early in the training, the patient stands on the movable surfaces with 2limb support and the therapist provides verbal cues of the direction of the perturbation stimulus, so the patient can become familiar with the training. Patients are progressed to singlelimb support on the injured limb in the first training session. During sessions 1 through 4, unidirectional perturbation stimuli should be administered at small amplitude and low frequency to allow the patient to become familiar with the training (Fitzgerald et al., 2000c). Once the patient feels comfortable with the training, the therapist begins to progress the training by removing verbal cues and administering the perturbation stimuli in random directions at mild to moderate amplitude and higher frequency. In addition, unidirectional destabilizing stimuli are replaced with 2directional and multidirectional stimuli depending on the patient’s tolerance (Fitzgerald et al., 2000c). Sportspecific activities are incorporated during the last 4 perturbation sessions to develop neuromuscular responses that might be carried over to activity (Fitzgerald et al., 2000c). Sportspecific activities can be initiated when patients demonstrate minimal balance disturbance on the tilt board and minimal co contraction responses on the roller board/stationary platform (Fitzgerald et al., 2000c). During sportspecific performance, sport activities are incorporated according to the patient’s sport practice. For example, basketball players may receive and throw the ball to the therapist, whereas soccer players might kick the ball with their https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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feet. During the last 3 training sessions, the destabilizing stimuli are administered at large amplitudes and multiple directions that include rotations and high frequency, so the subjects may elicit specific muscular cocontraction in the lower extremity (Eitzen, Moksnes, SnyderMackler, & Risberg, 2010; Fitzgerald et al., 2000c). FIGURE 3: PERTURBATION TRAINING

Perturbation training with a roller board and platform is generally initiated first, since this technique provides a more stable base of support. With this technique, the patient stands with one foot on the roller board and the other foot on the platform. The therapist asks the patient to stand with the knee flexed and to place equal weight on each foot during the training. During roller board/platform exercises, the patient is instructed to maintain the roller board in a steady position once the therapist starts moving it. While the therapist provides destabilizing force to the roller board, the patient is encouraged to develop muscle force that counteracts the destabilizing force. In addition, patients are discouraged from overcoming the applied force and from cocontracting the thigh and leg muscles to maintain the roller board in one place. In addition, the therapist observes the patient’s thigh and leg muscles to ensure that the selective muscle contractions occur during training. Clinicians use their clinical reasoning skills to make decisions concerning the progression in difficulty throughout the perturbation training. The progression is guided by the patient’s tolerance to the activity and the presence of adverse responses such as muscle soreness and joint effusion (Table 3).


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To provide a more unstable surface, the stationary platform may be removed. During the rollerboardonly perturbation training, the patient stands with singlelimb support on the injured limb and the therapist moves the roller board in multiple directions to disturb the patient’s standing balance. The therapist moves the board in a random pattern and at different magnitudes according to the patient’s responses, with small displacement amplitudes for patients with poor balance responses and large amplitudes for patients demonstrating a minimal loss of balance. The therapist instructs the patient on the roller board to maintain his or her balance. The final technique is tilt board training. During the first 3 training sessions, the patient stands on a tilt board and the therapist applies anteriorposterior and mediallateral oriented perturbation stimuli at random to challenge the patient’s balance. After the third training session, anterior posterior perturbation stimuli are replaced with diagonal stimuli by moving the tilt board into a diagonal position. During tilt board exercises the therapist instructs the patient to maintain balance during each of the destabilizing stimuli. Muscle Strengthening


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Patients receive a progressive exercise program to restore muscle strength that is required for participation in highlevel activities (Eitzen, Moksnes, SnyderMackler, & Risberg, 2010). The goal of the strengthening program is to maximize the quadriceps force production by utilizing high intensity and low repetition principles. Strengthening programs should include singlelimb exercise for the injured limb, including knee extension, knee flexion (leg curl), and leg press exercises. In addition, patients may also perform singlelimb squats, 2limb support squats with weights, and lateral and forward stepdowns using different step heights. Fitzgerald and colleagues provided a nonoperative ACL rehabilitation program with guidelines for resistance levels (Fitzgerald et al., 2000c). Parameters for resistance training consist of 2 sets of 10 repetitions at 50% of a 1repetition maximum (1RM) resistance, 2 sets of 8 repetitions at 75% of 1RM, and 2 sets of 5 repetitions of maximum volitional effort. The American College of Sports Medicine (ACSM) guidelines for the resistance training progression to induce muscle hypertrophy in healthy individuals recommend that loads corresponding to 112 RM be used (with emphasis on the 612 RM zone) in a periodized fashion using 1 to 2minute rest periods between sets at a moderate velocity (Kraemer et al., 2002). Resistance progression follows a “+2 principle,” which dictates that if the patient is able to perform an extra 2 repetitions above the target repetition, then the load will be increased in the next training session (Eitzen, Moksnes, SnyderMackler, & Risberg, 2010). For those patients who fail to restore quadriceps strength to the injured limb within 80% of the uninjured limb, strength training may be augmented with neuro muscular electrical stimulation (NMES) training (Fitzgerald et al., 2000c; SnyderMackler et al., 1995). The therapist must consider the patient’s sport and occupational needs, and individualize strengthening programs for each patient accordingly. Additionally, patients are encouraged to start a fitness strengthening program once they finish their rehabilitation program. The aims of the fitness strengthening program are to maintain muscular strength and to minimize quadriceps strength asymmetry between limbs. Agility Training Agility training is used to improve neuromuscular coordination of the muscles of the lower extremities and to increase patients’ ability to quickly change running directions (Fitzgerald et al., 2000c). This training should be initiated following successful completion of perturbation training and in the absence of patientreported knee instability. It is also suggested that effusion and ROM limitations be minimized prior to initiation of an agility program. Agility techniques include moving laterally, carioca, forward and backward running with quick start and stop, figureeight running, and 45 degree cutting and sprinting. Patients should start performing agility training at 35% to 50% of their maximum effort and progress to fulleffort training. Agility progression is based on the patient’s tolerance for activity and the presence or absence of knee pain and effusion. Sportspecific skills (basketball dribbling, ball throwing, ball kicking) may also be integrated into agility training when the patient is able to tolerate fulleffort training without pain or swelling. https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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Operative Management Patients with ACL deficiency who are classified as noncopers or those who experience multiple episodes of knee instability and impaired knee function following conservative rehabilitation are ideal candidates for ACL reconstruction. Furthermore, evidence shows that a torn ACL will not heal spontaneously with nonoperative rehabilitation (Barrack, Bruckner, Kneisl, Inman, & Alexander, 1990). Therefore, ACL reconstruction is the standard of care for those patients who intend to undergo surgery (Grontvedt et al., 1996). The goals of ACL reconstruction surgery are to restore mechanical knee stability, protect against further knee joint damage, and increase the likelihood of returning to preinjury sport levels (Hartigan et al., 2010; Myklebust & Bahr, 2005). Graft Type There are many surgical graft options for ACL reconstruction, including the type of graft (autograft or allograft), the donor site (patellar tendon or hamstring tendons), and the morphology of the new ligament (single, double, or quadruple bundles; LealBlanquet, AlentornGeli, Tuneu, Valenti, & Maestro, 2011). Patellar tendon and hamstring tendons (semitendinosus and gracilis; STG) are the most common graft sources used in ACL reconstruction surgery (Kartus, Movin, & Karlsson, 2001; LealBlanquet et al., 2011). In the past, patellar tendon autografts were the graft of choice for younger, active patients who desired to return to a high level of functional activity (Haut Donahue, Howell, Hull, & Gregersen, 2002), while STG autografts were recommended for older, inactive patients (Kartus et al., 2001; Reinhardt, Hetsroni, & Marx, 2010). However, there is currently no consensus on the best graft type to use (Foster, Wolfe, Ryan, Silvestri, & Kaye, 2010; Reinhardt et al., 2010). Patellar tendon autografts are easy to harvest and provide improved knee joint stability compared to STG autografts (LealBlanquet et al., 2011; Marrale, Morrissey, & Haddad, 2007; Reinhardt et al., 2010; Li et al., 2011). However, using a patellar tendon autograft is associated with quadriceps strength deficits and pain caused by donor site morbidity (Keays, BullockSaxton, Keays, Newcombe, & Bullock, 2007; LealBlanquet et al., 2011; Pinczewski et al., 2007), which can pose challenges to therapists when choosing quadriceps strengthening exercises. During rehabilitation following a patellar tendon autograft, the therapist should be aware of exercises and activities, such as overly aggressive quadriceps strengthening exercises and activities in the kneeling position, that may result in patellar tendon pain (Spindler et al., 2004). STG autografts provide slightly fewer postoperative complications compared to patellar tendon autografts (Keays et al., 2007; LealBlanquet et al., 2011; Li et al., 2011). Furthermore, the remnant parts of hamstring tendons eventually regenerate and strength improves to within normal limits between 6 and 12 months after ACL reconstruction (Krych, Jackson, Hoskin, & Dahm, 2008; Williams, SnyderMackler, Barrance, Axe, & Buchanan, 2004). Some advanced surgical techniques use quadruple bundle semitendinosus graft and doublebundle STG for ACL reconstruction. Studies have shown that using double or quadruplebundle https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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grafts results in decreased anterior and rotational knee joint laxity (Ardern, Webster, Taylor, & Feller, 2010; Siebold, Dehler, & Ellert, 2008). When an STG autograft is used, hamstringsstrengthening training is delayed to allow softtissue healing and to minimize irritation of the hamstrings donor site (Adams, Logerstedt, HunterGiordano, Axe, & SnyderMackler, 2012). Regardless of the source of the autograft tissue that has been harvested, donor site morbidity exists (Foster et al., 2010). A metaanalysis comparing functional outcomes between patellar tendon and STG autografts has failed to show any significant longterm differences (Biau, Tournoux, Katsahian, Schranz, & Nizard, 2006). Allograft tissues are less commonly used in ACL reconstruction surgery for highly active patients (Cohen & Sekiya, 2007). The advantages of allografts include a low risk of donor site morbidity, preservation of knee extensor and flexor muscle strength, and a lower incidence of arthrofibrosis (Foster et al., 2010; Marrale et al., 2007). However, there has been concern regarding potential allograft complications such as graft elongation and graft failure over time (Pinczewski et al., 2007). Metaanalysis studies have compared the results of the autograft and allograft tissues in term of their functional outcomes, failure rates, and stability. Autografts were favored over patellar tendon allograft, as patients who received autograft tissue experienced a lower rate of graft rupture and demonstrated higher performance on hop tests when compared to those patients who received allograft tissue. However, when irradiated and chemically processed grafts were excluded, results were not significantly different between the graft types (Krych et al., 2008; Tibor et al., 2010). Functional outcomes have been shown to be similar between autografts and allografts (Foster et al., 2010; Reinhardt et al., 2010). Because each graft type has advantages and disadvantages, there is no identified graft source that is clearly superior. Instead, graft type is often chosen based on the individual needs of the patient.

ImpairmentBased Interventions While ACL reconstruction is performed in the attempt to restore knee joint stability, many patients continue to present with poor functional performance after ACL surgery (Lohmander et al., 2004; Lynch et al., 2012; von Porat et al., 2004). It has been estimated that up to 60% of patients fail to return to preinjury activity levels following ACL reconstruction due to the presence of postoperative impairments (Ardern et al., 2011a; Chmielewski et al., 2011). Postoperative impairments may include pain secondary to surgery and at the donor site (Kartus et al., 2001), quadriceps strength deficits (Chmielewski et al., 2004; Hartigan et al., 2009), neuromuscular dysfunction (Hewett, Myer, Ford, & Slauterbeck, 2007), knee joint effusion, limited range of motion (especially into knee extension; Millett et al., 2001), and altered gait patterns (Rudolph et al., 1998). Pain Control and Effusion Management


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Knee pain related to the surgical incision or donor site morbidity is common after ACL reconstruction, especially in those patients who have received patellar tendon autograft. Though anterior knee pain is common following ACL reconstruction, it is not restricted to those patients with patellar tendon autograft. Evidence suggests that patients with STG autograft may also experience moderate anterior knee pain after ACL reconstruction (Yunes, Richmond, Engels, & Pinczewski, 2001). A study by Corry and colleagues reported that there are no significant differences between anterior knee pain with patellar tendon and hamstring autografts; however, pain with kneeling is commonly associated with patellar tendon autograft (Corry, Webb, Clingeleffer, & Pinczewski, 1999; Li et al., 2011). Most patients complain of local anterior knee pain described as pinpoint pain, while others complain of diffuse pain. Cryotherapy and electrical stimulation may be applied in an attempt to alleviate joint or anterior knee pain. Noxious electrical stimulation (2,500 Hz, 50 bursts/second, 12 on/8 off) for 10 to15 minutes can be used to manage localized pain (Manal, 2001). The noxious stimulation device has 2 pads (2 × 3 cm) that can be placed on the painful area with 1 to 2 cm between the pads to prevent current flow. The therapist instructs the patient that the treatment will be painful (noxious), with an initial tingling sensation progressing to noxious pain. In addition, patients are instructed to inform the therapist if the noxious stimulation feels like a hot poker or if it causes a burning sensation. In cases of more diffuse pain, a transcutaneous electrical nerve stimulation (TENS) can be used (4,500 Hz, 50 bursts/second, continuous [set off time to 0]) for 15 to 20 minutes (Bjordal, Johnson, & Ljunggreen, 2003). The TENS device has the option of a configuration of either 2 or 4 pads, depending on the size of the painful area. However, most individuals after the first 1 or 2 weeks following surgery have minimal pain and should not require extensive pain management modalities. Patellar taping may also be effective in managing anterior knee pain during exercise (Whittingham, Palmer, & Macmillan, 2004). Knee joint effusion is one of the most predominant symptoms of ACL injury and reconstruction surgery and is frequently encountered as an adverse effect during training. Cryotherapy has been found to significantly decrease pain and effusion, especially when augmented with massage, compression wraps, and elevation (Raynor, Pietrobon, Guller, & Higgins, 2005). Cryotherapy can be administered to the target tissue as a cold pack for 10 to 15 minutes or as an ice massage for 5 to 8 minutes. The use of cryotherapy is recommended as long as pain and effusion persist, in order to avoid ROM deficits, quadriceps inhibition, altered gait patterns, and a prolonged rehabilitation process (Cascio, Culp, & Cosgarea, 2004; Rice & McNair, 2010). Furthermore, cryotherapy is fairly inexpensive, easy to use, and rarely has adverse effects (Raynor et al., 2005; Rice, McNair, & Dalbeth, 2009). Other therapeutic techniques used for reducing effusion are compression wraps and elevation. The therapist teaches the patient to wrap the knee using an elastic bandage and fabric pad, also known as a donut cushion. Patients start wrapping by placing the donut cushion on the top of the knee and then wrapping the elastic bandage from the lower leg up to the thigh using a figure8 pattern (Figure 4). Patients are instructed to keep https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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the knee wrapped and elevated as long as possible to improve fluid re absorption, especially during the first week after injury or surgery. Patients are also instructed to unwrap the knee every 2 hours to prevent blocking circulation to the lower leg and foot. By reducing impairments, cryotherapy can enhance rehabilitation and improve the functional outcomes in patients with ACL deficiency and ACL reconstruction. FIGURE 4: FIGURE8 COMPRESSION WRAP

ROM Deficit Management ROM deficits are common impairments after ACL reconstruction and are associated with poor knee functional outcomes (Benum, 1982; Shelbourne, Urch, Gray, & Freeman, 2012). Moreover, some patients continue to walk with asymmetrical knee angles for long periods of time after ACL reconstruction (Roewer, Di Stasi, & SnyderMackler, 2011). Walking with a stiff knee may place an excessive load on the articular cartilage and aggravate osteoarthritis processes in the joint. Persistent knee extension motion deficit may also cause anterior knee pain, quadriceps weakness, and increased risk of knee osteoarthritis (Shelbourne, Patel, & Martini, 1996; Shelbourne, Urch, et al., 2012). ROM deficits may result from several factors, including preoperative motion loss (Mauro et al., 2008; Shelbourne & Johnson, 1994), length of time between the injury and surgery (Kwok, Harrison, & Servant, 2013), surgical techniques (including improper surgical techniques; Harner, Irrgang, Paul, Dearwater, & Fu, 1992; Millett et al., 2001), and prolonged post operative immobilization (Cosgarea, Sebastianelli, & DeHaven, 1995). Knee extension deficits are common following ACL reconstruction in patients with bonepatellartendonbone autografts. Many authors suggest that arthrofibrosis scar nodules, also https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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known as cyclops lesions, may develop within the joint when a patellar tendon autograft is harvested (Harner et al., 1992; Logerstedt & Sennett, 2007; Millett et al., 2001). During knee extension motion, the scar nodule impinges underneath the femoral notch and blocks the terminal knee motion. Arthroscopic debridement has been effective in improving knee extension ROM when arthrofibrosis is the cause of knee extension deficits (Jackson & Schaefer, 1990). One of the goals of ACL rehabilitation is to restore full knee extension early after ACL injury and ACL reconstruction. Loss of knee extension ROM immediately following ACL reconstruction is common (Adams et al., 2012). Early emphasis on restoring knee extension is paramount in maximizing short and longterm outcomes. The use of a knee brace locked in full extension is suggested in the immediate post operative stage following ACL reconstruction to reduce the likelihood of developing knee extension ROM deficits. The patient with persistent knee extension deficits beyond the second postoperative week can begin stretching exercises – such as prone hangs and bag hangs with weights – that use lowload and longduration principles to achieve full knee extension (Figure 5; Adams et al., 2012; Wilk, Reinold, & Hooks, 2003). In persistent cases of knee extension ROM loss or knee flexion contracture, dropout casting may be used to resolve extension ROM deficits. Dropout casting maintains the length of the connective tissues by applying constant load over long periods of time (Adams et al., 2012). In order to restore knee flexion ROM, various techniques, such as wall slides, stationary biking, and patellar mobilization, can be used immediately after ACL reconstruction; however, these techniques must be used with care within the constraints of protective ROM to avoid stressing the newly harvested graft tissue and disrupting the incision site stitches. Flexion ROM exercises may be limited by concomitant surgical procedures such as meniscal repair or MCL reconstruction. Between 3 to 5 weeks after ACL reconstruction surgery, the therapist may also begin applying anterior to posterior tibiofemoral mobilizations at different knee joint angles to facilitate flexion ROM gains. ROM exercises should be continued with patients until ROM in the surgically repaired knee is equal to ROM in the contralateral knee. FIGURE 5: KNEE STRETCHING TECHNIQUES


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Bracing Patients will typically use a knee immobilizer such as a droplock knee brace while walking and sleeping in the immediate postoperative phase (Adams et al., 2012). Once patients are able to perform straight leg raises without lag and knee joint effusion is minimized, the knee immobilizer may be replaced with a functional knee brace (Adams et al., 2012; Chew, Lew, Date, & Fredericson, 2007; Wright & Fetzer, 2007). However, the use of a functional knee brace is surgeondependent and becoming less routine. Although functional knee bracing is also often recommended for patients with ACLdeficient knees (Logerstedt et al., 2010; Swirtun, Jansson, & Renstrom, 2005), evidence suggests that current functional bracing technologies do not sufficiently restore normal biomechanics to the ACL deficient knee, protect the reconstructed ACL, or improve longterm patient outcomes (Smith, LaPrade, Jansson, Årøen, & Wijdicks, 2013). Functional bracing does not result in superior functional or patientreported outcomes, and has not been shown to reduce risk of reinjury following surgery (Birmingham et al., 2008). While the standard of care in the past has been to prescribe functional knee bracing following ACL reconstruction for return to sports (Marx et al., 2003), knee bracing is now less common. Quadriceps Strengthening Quadriceps muscle strength deficits, ranging from 15% to 40%, and atrophy of the involved limb are the predominant impairments after ACL rupture and can persist for years after ACL reconstruction (Chmielewski et al., 2004; de Jong et al., 2007; Feller & Webster, 2003; Hartigan et al., 2009). Strength deficits, often attributed to quadriceps activation failure after ACL injury or surgery, have a negative impact on knee joint function (Chmielewski et al., 2004; de Jong et al., 2007; Hartigan et al., 2009). Quadriceps activation failure is the result of intraarticulate changes in the knee joint, a condition called arthrogenic muscle inhibition (Hart et al., 2010; Lynch et al., 2012). Early initiation of neuromuscular electrical stimulation (NMES) after surgery has been found to be effective in improving quadriceps muscle activation and strength (Lynch et al., 2012; Snyder Mackler et al., 1994). In addition to NMES, quadriceps strength training may include the use of high intensity, low repetition weightbearing (WB), nonweightbearing (NWB), and eccentric exercises. These strengthening techniques may be augmented with NMES. Progression through quadriceps strength training is based on criterionbased guidelines to maximize the quadriceps strength. The following are the most commonly used quadriceps strengthening exercises in rehabilitation programs. Neuromuscular Electrical Stimulation


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NMES is commonly used for strengthening the quadriceps muscles following ACL injury and ACL reconstruction (Lynch et al., 2012). This technique is most beneficial when quadriceps weakness is due to arthrogenic muscle inhibition (Lynch et al., 2012; Rice & McNair, 2010). Therefore, early incorporation of NMES into the treatment program after ACL injury or reconstruction surgery is recommended to avoid quadriceps muscle inhibition, which is considered a barrier to effective rehabilitation (Rice & McNair, 2010). NMES training is recommended as an adjunct treatment for patients whose injured limb quadriceps muscles exert a maximum voluntary isometric force of less than 80% of the uninjured limb (Adams et al., 2012; Delitto et al., 1988; SnyderMackler et al., 1995; SnyderMackler et al., 1994). A recent systematic review suggests that a stimulus waveform of 1.0 to 2.5kHz frequency alternating current, with a 2 to 4millisecond burst, may yield the best torque output with the least patient discomfort (Kim, Croy, Hertel, & Saliba, 2010). A commonly used NMES protocol consists of 10 electrically stimulated isometric contractions of the quadriceps muscles, with 10 seconds on and 50 seconds off, with a 2,500 Hz stimulus delivered at 75 bursts per second (Fitzgerald, Piva, & Irrgang, 2003; SnyderMackler et al., 1994). The electrical current amplitude for NMES must be equivalent to the electrical current needed to produce 50% of maximum voluntary isometric contraction of the injured limb’s quadriceps muscle in order to improve the quadriceps muscle strength (Fitzgerald et al., 2003). NMES training can be performed on a dynamometer with the knee positioned between 60° to 85° of knee flexion (Figure 6; Delitto et al., 1988; SnyderMackler et al., 1995). NMES training should be incorporated the first few days after injury or surgery in conjunction with a progressive quadriceps strengthening program to avoid quadriceps strength deficits and activation failure (Rebai et al., 2002). Patients with patellar tendon autograft may experience donor site pain during forceful quadriceps contractions at high knee flexion angles. If a dynamometer is unavailable, a modified NMES protocol can be used to produce similar results (Fitzgerald et al., 2003). The modified NMES protocol places the patient in a supine position with the knee in full extension. The NMES stimulus is the same as previously described. The intensity is set to maximum patient tolerance once a full, sustained, tetanic contraction (sustained muscle contraction without an interval of relaxation) of the quadriceps is achieved. One advantage of NMES is that it does not require delaying the training program until impairments have been resolved and can be used regardless of the presence of joint effusion or ROM limitation to restore normal quadriceps activation (Lynch et al., 2012). Once quadriceps muscle strength of the injured limb is greater than 80% of the uninjured limb, NMES can be discontinued and patients may continue with their progressive strengthening program (Adams et al., 2012). All patients are recommended to participate in a progressive strengthening program to maximize quadriceps strength and restore normal limb symmetry in quadriceps strength. Applying NMES in combination with highintensity progressive quadriceps strengthening exercises results in greater strength improvement in ACLdeficient and ACL reconstructed patients when compared with standard exercise alone (Kim et al., 2010). https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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FIGURE 6: NEUROMUSCULAR ELECTRICAL STIMULATION TO QUADRICEPS MUSCLES USING A PORTABLE DEVICE

Weightbearing and NonWeightbearing Exercises Weightbearing (WB) and nonweightbearing (NWB) exercises, also known as closed chain and open chain exercises, respectively, are used in rehabilitation programs for patients following ACL injury and ACL reconstruction surgery to improve quadriceps strength and dynamic knee stability (Escamilla, Macleod, Wilk, Paulos, & Andrews, 2012; Escamilla et al., 2009; Fleming, Oksendahl, & Beynnon, 2005). During the first few weeks after ACL reconstruction surgery, patients begin loading their operated knee as tolerated to manage pain and to protect the healing tissue. Biological incorporation of soft tissue grafts such as STG requires more time (typically 8 to 12 weeks) when compared to grafts incorporating bone plugs (Buckwalter & Grodzinsky, 1999). Therefore, rehabilitation following ACL reconstruction may be modified according to the time frame https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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of biological healing and graft remodeling (Kvist, 2006). Exposing the new graft tissues – which are undergoing remodeling and maturation processes – too early to an excessive and uncontrolled load may cause graft rupture or graft failure (Mikkelsen, Werner, & Eriksson, 2000). Therefore, WB and NWB exercises should be properly incorporated into the rehabilitation program to avoid the adverse impact of overloading the immature graft (Escamilla et al., 2012; Mikkelsen et al., 2000; Perry, Morrissey, King, Morrissey, & Earnshaw, 2005). Current, researchbased thinking is that WB exercises at low knee flexion ROM (0° to 60°) should be implemented early after ACL reconstruction because WB exercises are safe and place less shear force on the new graft when compared to NWB exercises (Glass, Waddell, & Hoogenboom, 2010). WB exercises are considered safe and beneficial because they involve more than one muscle group and joint simultaneously, as is the case with squats, leg presses, and stepup and stepdown techniques (Figure 7) (Escamilla, 2001; Escamilla et al., 2012). Although overloading the reconstructed graft may cause graft rupture or failure, unloading the graft may delay recovery and weaken the graft strength (Buckwalter & Grodzinsky, 1999). Thus, early resumption of activities that place controlled load onto the healing tissue enhances graft tissue strength and function (Buckwalter & Grodzinsky, 1999). On the other hand, NWB exercises have adverse effects on the healing graft when they are performed at a range between 0° to 45° of knee flexion (Mikkelsen et al., 2000; Perry et al., 2005). Several studies report that early initiation of NWB exercises at small knee flexion angles induces anterior shear forces in the knee joint. Evidence shows that anterior knee shear force is harmful because it causes increased tension on the healing graft and fixation (Escamilla et al., 2012; Fleming et al., 2005). However, administration of WB and NWB exercises (Figure 8) as part of an ACL rehabilitation program resulted in higher quadriceps strength and return to sports when compared to WB exercises alone (Mikkelsen et al., 2000). It is currently recommended that a combination of WB exercises between 0° to 45° of knee flexion and NWB exercises from 90° to 45° be initiated in the early postoperative phase (Escamilla et al., 2012; Escamilla et al., 2009; Fleming et al., 2005; Perry et al., 2005). Exercising within the defined ROM for each exercise results in less strain applied on the healing graft as well as enhanced strengthening of quadriceps and other lower extremity muscles (Mikkelsen et al., 2000). After the first 6 weeks following ACL reconstruction, which is considered to be within the initial biological healing time frame, patients may begin to gradually progress WB and NWB exercises throughout full knee range of motion to improve quadriceps strength (Mikkelsen et al., 2000).


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FIGURE 7: WEIGHTBEARING EXERCISE

FIGURE 8: NONWEIGHTBEARING EXERCISE

Eccentric Muscle Strengthening


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In an ACL rehabilitation program, the goal of eccentric training is to resolve muscular impairments by providing interventions that can safely and effectively overload the quadriceps muscle to increase the muscle size and to improve the muscle strength. Particular consideration is given to the type, frequency, and magnitude of strength training due to concern for increasing the anterior tibia translation and shear force that is applied to the healing graft (Beynnon, Uh, et al., 2005). In addition to the NMES and WB/NWB exercises, eccentric exercises are used to improve the quadriceps strength and force generation after ACL injury and reconstruction surgery. Generally, muscle force production is greatest when an external load exceeds a muscle’s force capacity and when the muscle fibers are lengthening eccentrically. Eccentric contraction occurs when the muscle fibers are lengthening, as in lowering a weight through a range of motion. During eccentric training, the contractile forces generated by the muscle are less than the external load, which causes the muscle to lengthen. The tension developed in the muscle fibers during the lengthening phase of muscle contraction is considerably greater than the tension developed when muscle fibers are shortening, as in a concentric contraction (Lorenz & Reiman, 2011). Eccentric training for the quadriceps muscles is considered safe and effective (Beynnon, Uh, et al., 2005; Gerber et al., 2007). Application of eccentric resistance training as early as 3 weeks after ACL reconstruction surgery increases the crosssectional area and strength of the quadriceps muscle without compromising the tissue of the new graft (Gerber, Marcus, Dibble, Greis, & LaStayo, 2006). Evidence suggests that incorporation of eccentric resistance training into ACL rehabilitation programs during the first 15 weeks following ACL reconstruction induces greater increases in muscle volume, strength, and knee functional measures when compared to ACL rehabilitation without eccentric resistance training (Gerber et al., 2006). A metaanalysis study comparing eccentric to concentric training reported that eccentric training is more effective than concentric training in increasing muscle strength, muscle mass, and rate of force development (Faulkner, 2003). Eccentric training elicits greater changes in neural activation and muscle hypertrophy (LaStayo et al., 2003). Eccentric training may be incorporated into WB or NWB activities. Therapists instruct the patient to initiate eccentric training at lower intensities and progress to highintensity exercises that involve exercisespecific machines such as the leg press and squat rack (Lorenz & Reiman, 2011). During squats, patients lower themselves down on the reconstructed limb and then raise themselves back up with the assistance of the nonoperated limb. In leg press, patients straighten the nonoperated knee concentrically and follow by flexing the reconstructed knee eccentrically. Patients may start as early as the third postoperative week with light resistance for 20 to 30 repetitions and progress to more challenging resistance for 30 to 60 repetitions after 12 weeks. Executing strengthening exercises throughout the entire knee flexion ROM early after ACL reconstruction may be problematic because these exercises place tension on the new graft; therefore, patients begin performing WB eccentric training in a limited ROM of knee flexion (0° to 40°). Early after ACL reconstruction, patients can perform NWB eccentric training on a limited knee flexion ROM (90° to 45°). https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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At 6 weeks following surgery, patients may perform both WB and NWB eccentric exercises at larger knee flexion ROM (0° to 90°) to maximize quadriceps strength (Lorenz & Reiman, 2011). The ultimate goal of strength training is to restore quadriceps strength symmetry between limbs, and thus to minimize the potential risk of reinjury of the reconstructed limb and contra lateral limb. Once patients finish their rehabilitation programs, they are encouraged to start strength training at a gym to improve and maintain their quadriceps strength. In addition, patients are instructed to expand their strength exercises to include strengthening of the uninvolved limb when symmetric quadriceps strength has been achieved. Currently, the integration of controlled eccentric training as part of rehabilitation programs following ACL injury or reconstruction is highly recommended to maximize quadriceps muscle strength and patient outcomes. Neuromuscular Training Rehabilitation programs that focus only on restoring joint motion, increasing quadriceps muscle strength, and improving agility skills do not optimize return to all previous activity levels. Rehabilitation programs should emphasize treatment techniques that facilitate appropriate neuromuscular strategies for participation in highlevel activities that involve jumping, cutting, and pivoting maneuvers. Patients with ACL deficiency or ACL reconstruction exhibit poor proprioception resulting from damage to the mechanoreceptors that are embedded in the articular structures of the knee and the ACL (Lephart, Pincivero, Giraldo, & Fu, 1997). Neuromuscular training increases neuromuscular awareness and improves dynamic stability of the knee joint (Fitzgerald et al., 2000b, 2000c). Neuromuscular training programs include balance exercises, dynamic stabilization exercises, plyometrics, agility drills, and perturbation training. The therapist progresses the exercise difficulty from low intensity to high intensity maneuvers and decreases patients’ base of support by progressing from 2limb support to 1limb support. As balance improves, squatting or sportspecific activities – such as dribbling a basketball, kicking a football, or throwing a baseball – may be implemented during balance training. Examples of dynamic knee stability exercises include the Star Excursion Balance training and single limb squat. In the Star Excursion Balance training, patients stand on single limb support in the center of an eightline grid (Figure 9). Patients are asked to reach with the free foot as far as possible along each of the eight lines. Although balance exercises have been shown to improve patients’ functional outcomes and are often used in rehabilitation programs, the guidelines for the balance exercises are not well established (Herrington et al., 2009).


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FIGURE 9: STAR EXCURSION BALANCE TRAINING

Perturbation training, described earlier, may be incorporated into the postoperative rehabilitation program as soon as patients are pain free, knee joint effusion is less than trace, and full knee ROM is restored. Plyometrics Plyometric training refers to quick and powerful movements that involve quickly stretching the muscletendon unit during an eccentric maneuver to produce a subsequently stronger muscle contraction during a concentric maneuver (Chmielewski, Myer, Kauffman, & Tillman, 2006). These types of exercises are widely designed to resolve postinjury neuromuscular impairments, increase muscle strength and power production, and prepare patients for rapid movements and high force production needed during highlevel activities (Myer, Ford, Brent, & Hewett, 2006). Plyometric maneuvers constitute a natural part of most sport movements and involve double and singlelimb jumping, hopping, and skipping activities (Paterno et al., 2004). In clinical practice, plyometric exercises are integrated into rehabilitation programs to bridge the gap between traditional rehabilitation exercises and sportspecific activities that include explosive movements (Cordasco, Wolfe, Wootten, & Bigliani, 1996). One example of plyometric exercise typically incorporated into postoperative rehabilitation is hopping. Hopping exercises progress from double legged support to singlelegged hopping as the patient gains strength, control, and confidence. Single legged hopping can include hopping up and down on a step (Figure 10), lateral hopping, and skating, where a patient stands on one leg and hops sideways with a soft, deep, and steady landing on one leg, and then hops back on the other leg (Eitzen, Moksnes, SnyderMackler, Engebretsen, & Risberg, 2010). Plyometric exercise is typically implemented in later phases https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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of ACL rehabilitation to prepare athletes for return to their desired activity levels. Plyometric exercises may be initiated for patients who can tolerate moderate loading during strengthening exercises and perform functional movements in a proper pattern (Chmielewski et al., 2006). Plyometric exercises are initiated at low levels of intensity and then progress to higher intensity levels when patients are confident with the task and have tolerated previous intensity levels well. Progressing through the levels of difficulty of plyometric exercises is guided by the absence of adverse responses such as joint pain or joint swelling, as shown in Table 4 (Chmielewski et al., 2006). When performing exercises that require singlelegged landing, patients are instructed to land while maintaining proper knee alignment over their toes, with a soft landing to avoid further joint damage (PalmieriSmith & Thomas, 2009). Plyometric exercises are incorporated into reinjury prevention programs to improve the neuromuscular and biomechanical characteristics of injured athletes (Myer et al., 2006). In addition, plyometric training has been found to significantly minimize the incidence of injury in female athletes when augmented with dynamic stabilization training (Mandelbaum et al., 2005; Myer, Ford, Palumbo, & Hewett, 2005). FIGURE 10: PLYOMETRIC EXERCISES

PROGRESSION Soreness Rules Before returning to participation in high demand activity levels, patients should demonstrate painfree performance of loading activities and tolerate these activities without experiencing adverse responses such as joint pain, joint effusion, or muscle soreness. These adverse responses, sometimes https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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experienced by patients progressing to a higher level of therapeutic exercise, can cause muscle inhibition, joint deterioration, and an increase in the number of treatment sessions required to achieve rehabilitation goals (Chmielewski et al., 2006). Therefore, a patient’s activity level during a rehabilitation program must be monitored to minimize the potential for or recurrence of impairments. ACL rehabilitation programs should use effusion grades and soreness rules to monitor therapeutic exercise progression of patients following ACL injury and reconstruction. The use of soreness rules depends on the timing of adverse effects experienced during performance of the exercises. (See Table 4.) When an adverse response is encountered, the recovery period will be prolonged until the impairment has completely resolved. In addition, the intensity of the next exercise session should be reduced to a lower level to avoid recurrence of soreness or effusion. If joint pain or joint swelling are experienced after exercising, but the symptoms resolve before the next rehabilitation visit or after the next warmup, then the program should not be progressed but rather maintained at the same level and monitored for reoccurrence of symptoms. Chmielewski and colleagues suggest that a patient should tolerate 2 to 3 sessions at a specific intensity without any adverse responses before the intensity of the program is progressed (Chmielewski et al., 2006).

Running, Agility, and ReturntoSport Training Following ACL injury or ACL reconstruction, patients may develop cardiovascular deconditioning due to the lack of aerobic training. Patients with an ACLdeficient or an ACLreconstructed knee who wish to return to sport or recreational activities are encouraged to initiate a gradual running progression to promote cardiovascular endurance, improve oxygen consumption, increase lower extremity muscle strength, and increase force generation from the dynamic nature of the running (Adams et al., 2012). A running progression is incorporated into the rehabilitation program when patients are at least 8 weeks after ACL reconstruction and have met the criterion of 80% quadriceps strength index and have trace or less effusion (Adams et al., 2012). Patients are instructed to begin a graded running https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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program that includes jogging and walking intervals for 2 miles (3.2 km) on level surfaces (either a running track or treadmill). The program is progressed by increasing the joggingtowalking time ratio. At the beginning of the program, the ratio of jogging to walking distance is small. The ratio of jogging to walking distance, as well as the distance and pace, is gradually increased if the patient tolerates the previous stage without muscle soreness, joint pain, or effusion. (See Table 5.) For patients with an ACL injury who pursue nonoperative treatment, running progression may begin once they meet the criteria of no pain; effusion of less than trace grade; full knee ROM; 70% quadriceps strength index; and painfree, unilateral hopping on the injured limb (Fitzgerald et al., 2000c).

Upon successful completion of a running program, patients may progress to agility training. This program is similar to the agility program listed for nonoperative treatment. Agility training should consist of cutting and pivoting exercises of increasing intensity that simulate the demands of the patient’s sport. Agility exercises are incorporated into the ACL reconstruction rehabilitation program to improve the neuromuscular coordination of the lower extremity muscles and to increase patients’ ability to quickly change running directions (Fitzgerald et al., 2000c). As running and agility programs are progressed toward returntosport training, a systematic approach for sport participation is recommended that accounts for pain and apprehension (see Table 6; Adams et al., 2012).


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RETURNTOSPORT CRITERIA

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atients with an ACL injury are frequently counseled to undergo ACL reconstruction with the expectation of restored mechanical knee stability and normal knee function that facilitates return to their previous levels of activity (Marx et al., 2003; Myklebust & Bahr, 2005). However, evidence shows that although patients demonstrate restoration of mechanical knee stability after ACL reconstruction, this surgery does not ensure the ability to return to previous levels of activity or prevent future joint degeneration (Dye et al., 1999; Gobbi & Francisco, 2006). Additionally, intent to return to sports is not predictive of actual return to play. Ardern and colleagues reported that 63% of athletes returned to their preinjury participation level, but only 44% returned to competitive sports (Ardern et al., 2011b). Patients may reduce their activity levels for a variety of reasons, including knee impairments and fear of reinjury (Myklebust & Bahr, 2005; Webster et al., 2008). Furthermore, not all athletes choose to or have the opportunity to return to previous activity levels or sports. The first several months following ACL reconstruction are considered the time of greatest vulnerability for athletes attempting to return to their previous level of activity. Not only are functional performance deficits (Ardern et al., 2011a; Hartigan et al., 2010) and movement asymmetries (Hartigan et al., 2009; Paterno et al., 2010; Roewer et al., 2011) commonplace, but reinjury risk is also highest during the first 12 months after ACL reconstruction (Laboute et al., 2010). One of the challenges in the management of ACL injury and reconstruction has been to appropriately select tests that can detect limbtolimb asymmetries, assess global knee function, and determine a patient’s readiness to return to sport. After ACL injury and reconstruction, many individuals continue to exhibit impaired function characterized by dynamic knee instability and pain, reduced range of motion, quadriceps strength deficits, reduced functional performance, neuromuscular dysfunction, and biomechanical maladaptations that may account for inferior patient outcomes and risk for second injury (Daniel et al., 1994; de Jong et al., 2007; Hartigan et al., 2010; Paterno et al., 2010; von Porat et al., 2004). Batteries of tests can predict the risk for https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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musculoskeletal injuries (Kiesel, Plisky, & Voight, 2007), classify individuals early after ACL injury (Fitzgerald et al., 2000a), and identify important limb asymmetries after ACL injury and reconstruction (Gustavsson et al., 2006; Neeter et al., 2006). A battery of tests and measures – including quadriceps strength testing, 4 singlelegged hop tests, and 2 patientreported questionnaires – has been utilized to aid objective determination of return to sport (RTS) readiness following ACL injury and reconstruction (Di Stasi et al., 2013; Fitzgerald et al., 2000c; Hartigan et al., 2010). It is recommended that patients with a desire to return to sports achieve 90% or better on a battery of tests to ensure readiness for return to sports. (See Table 7.) Once cleared, patients should not directly return to competition. Athletes should begin with lower level sports participation in practice and gradually build up to competition while monitoring pain, effusion, and ROM (Fitzgerald et al., 2000b). TABLE 7: RETURNTOSPORT CRITERIA Patient must achieve 90% or more on: Quadriceps strength index All singlelegged hop tests Knee Outcome SurveyActivity of Daily Living Scale Global rating score of knee function Patients with ACL reconstruction should wait at least 12 weeks after surgery. Patients with ACL deficiency can begin participation in sport activities once they pass returntosport criteria.

Knee Function Outcomes Successful outcomes following nonoperative management of ACL injury are often measured by the achievement of limbtolimb symmetry during clinical testing and return to preinjury levels of activity performance. While some individuals with ACL injury can return to unrestricted functional activity without undergoing reconstruction surgery, many choose to modify their level of activity to less strenuous activities, or need to undergo reconstruction surgery in order to return to preinjury activity levels (Logerstedt et al., 2010). Of those patients classified as potential copers who have undergone specialized neuromuscular training (perturbation training), 72% to 79% are able to successfully return to all preinjury activities at the preinjury level for a limited time period (Fitzgerald et al., 2000c; Hurd et al., 2008a). Longterm outcomes following nonoperative management are mixed. A study by Kostogiannis and colleagues reported that only 42% of patients with ACLdeficient knees classified as potential copers were able to return to their preinjury activity level within 3 years after nonoperative ACL management (Kostogiannis et al., 2007). However, Hurd and colleagues (2008a) reported that 10 years after nonoperative ACL management, 72% of potential copers had been able to return successfully https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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to their preinjury activity level. The high success rate in the latter study can be attributed to the use of a screening exam to classify patients and the incorporation of neuromuscular training into the nonoperative rehabilitation program. When the decision for pursuing nonoperative ACL management to return to high level activities was based on patient selfselection, only 23% to 42% were able to resume highlevel activities (Hughes & Watkins, 2006; Hurd et al., 2008a). These findings highlight the importance of utilizing a systematic screening exam for patient management following ACL injury. Patients who did not have reconstructive surgery scored their knee functional level at near normal to normal levels on selfreported measures at 1 year after ACL injury, maintained their functional level at 3 years, and had a modest decline in function at 15 years (Kostogiannis et al., 2007; Moksnes & Risberg, 2008). In studies that investigated singlelegged hop tests as a functional outcome measure, patients had near normal or normal limb symmetry at 1 year (de Jong et al., 2007; Moksnes & Risberg, 2008) and maintained this function at 4 years after ACL injury (Moksnes et al., 2008). Ageberg and colleagues (2007) reported good to normal quadriceps strength up to 5 years after ACL injury. In a 2008 study, 70% of patients initially classified as noncopers became true copers following nonoperative rehabilitation, as demonstrated by return to previous activity level without episodes of giving way 1 year after injury (Moksnes & Risberg, 2008). Multiple studies have reported good selfreported outcomes following nonoperative management of ACL injury, indicating that surgical reconstruction is not mandatory in all cases for good results. Clinical tests and measures that help therapists to identify patients at risk for poor outcomes following injury are of great clinical importance. According to one study, a test battery of performancebased and patient reported outcomes demonstrated that those patients who successfully returned to highlevel activity after nonoperative management of an ACL injury had an average of less than 10% deficit on their initial evaluation scores (see Table 8 for a list of clinical measures that can be used for the initial evaluation; Fitzgerald et al., 2000c).


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With regard to patients who have undergone ACL reconstruction, most studies investigating shortterm knee functional outcomes report that the majority of patients improve with treatment. Logerstedt and colleagues have reported that normal limb symmetry index (LSI) related to quadriceps strength and singlelegged hop performance is restored at 6 months and continues to improve 12 months after ACL reconstruction surgery (Logerstedt, Grindem, et al., 2012). Studies have shown that knee functional performance measured by singlelimb hop tests improve at 6 months to 12 months (Moksnes & Risberg, 2008), and continue to improve from 2 to 5 years after surgery (Ageberg et al., 2008; Hopper, Strauss, Boyle, & Bell, 2008). Scores on selfreported measures also continue to improve after ACL reconstruction surgery. These outcomes are similar to findings reported in patients with ACLdeficient knees (Grindem et al., 2012; Moksnes & Risberg, 2008). In a study of returntosport outcomes at 1 year following ACL reconstruction, patients reporting return to preinjury levels of sports participation had less knee joint effusion, fewer episodes of knee instability, lower knee pain intensity, higher quadriceps peak torque/body weight, higher IKDC score, and lower TSK11 score. The strongest contributors to returntosport status were selfreported knee function (IKDC score), frequency of knee instability, and knee joint effusion, indicating that these factors may have the strongest influence on returntosport outcomes at 1 year postsurgery (Lentz et al., 2012).

SUMMARY

T

he goal of this course has been to provide the learner with the latest information concerning ACL injuries, the therapeutic techniques used to manage patients after ACL injury, and a criterionbased progression of activities. The findings of evidencebased practice research have contributed significantly to improving the rehabilitation protocols for patients with ACL deficiency and ACL reconstructions. Currently, rehabilitation programs emphasize addressing the impairments related to knee joint pain, joint effusion, ROM deficits, and muscle strength deficits that are present in patients with ACL deficiency and ACL reconstruction. Many clinicians incorporate an accelerated rehabilitation protocol with the hope of earlier restoration of the patient’s knee function to assist in the return to pre injury activity levels. The rehabilitation protocol emphasizes earlier initiation of quadriceps strengthening training, neuromuscular training, and dynamic activities to improve the patient’s outcome (Wilk, Macrina, Cain, Dugas, & Andrews, 2012). Decisions for progressing through the rehabilitation program depend on meeting clinical milestones, the absence of adverse responses and muscle soreness, and patients’ ability to perform the activity. Integration of neuromuscular control of the lower extremity to the ACL rehabilitation is a key factor to improving knee joint dynamic stability, correcting gait pattern, and improving knee functional performance (Chmielewski et al., 2005). With advanced surgical techniques and rehabilitation guidelines reaffirmed by the latest evidencebased practice, therapists can provide patients with the best outcomes after the ACL injury and reconstruction surgery. Investigators continue to push ACL research https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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forward to provide therapists with the best rehabilitation guidelines and with effective objective measures for determining the progression and return to preinjury activity levels.


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EXAM QUESTIONS CURRENT CONCEPTS IN ACL INJURY, SURGERY, AND REHABILITATION This is for your reference only. To complete the exam, login to your account at http://www.westernschools.com

Questions 1–20 Note: Choose the one option that BEST answers each question.

1. The posterolateral bundle of the anterior cruciate ligament (ACL) is slack a. in full knee extension. b. in deep flexion. c. throughout the full range of motion. d. throughout the midrange of motion.

2. Relative to the femur, the ACL is the primary restraint to the a. anterior translation of the tibia. b. posterior translation of the tibia. c. medial translation of the tibia. d. lateral translation of the tibia.

3. Patients who benefit most from ACL reconstruction are individuals a. with recurrent instability who wish to return to multidirectional activities. b. who are older, inactive, and do not want to wear a knee brace. c. with weak quadriceps and hamstring muscles. d. with range of motion deficits.

4. One nonmodifiable risk factor associated with noncontact ACL injury is https://www.westernschools.com/Portals/0/html/H8059/g5aztN_files/OEBPS/Text/Section0003.html

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a. having a low body mass index. b. being female. c. having a wide femoral notch. d. strong hamstrings.

5. One risk factor for an initial and second ACL injury is a. poor lower extremity neuromuscular control. b. good trunk neuromuscular control. c. increased hamstring flexibility. d. equal distribution between limbs during activities.

6. Poor dynamic knee stability is more common in a. women than men. b. younger patients than older patients. c. patients with a workrelated mechanism of injury than in patients with a sports activity mechanism of injury. d. patients with a contact mechanism of injury than in patients with a noncontact mechanism of injury.

7. A preoperative predictor of poor functional outcomes following ACL reconstruction is a. knee joint effusion. b. singlelegged hop tests. c. antalgic gait. d. poor quadriceps muscle strength.

8. ACL reconstruction is not recommended until a. the global rating scale of perceived function (GRS) is >60%. b. pain is rated at 0/10 on a visual analog scale. c. the patient has returned to preinjury activity levels. d. the quadriceps index is ≥80%.

9. Normal knee extension range of motion is within a. 2° of neutral. b. 5° of neutral. c. 2° of the contralateral knee.


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d. 5° of the contralateral knee.

10. The most accurate clinical test to detect acute ACL tears is the a. anterior drawer test. b. valgus stress test. c. Lachman test. d. singlelegged hop test.

11. Singlelegged hop tests should not be completed following ACL injury if a. the quadriceps index is 85%. b. effusion is greater than a trace. c. the patient has not yet had ACL reconstruction. d. the patient is less than 6 months out from ACL reconstruction.

12. A patientreported outcome that measures psychological responses to return to sport activities following ACL reconstruction is the a. Marx activity scale. b. international knee documentation committee 2000 (IKDC 2000). c. global rating scale of perceived function (GRS). d. ACLReturn to Sport after Injury (ACLRSI) scale.

13. The structure least likely to be injured along with the ACL is the a. meniscus. b. lateral collateral ligament. c. medial collateral ligament. d. articular cartilage.

14. A patient is classified as a potential noncoper if his or her a. effusion is graded as a trace. b. singlelegged crossover hop is >80%. c. global rating scale of perceived function (GRS) score is