Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-014-3409-3
SPORTS MEDICINE
Plantaris injuries in elite UK track and field athletes over a 4‑year period: a retrospective cohort study Noel Pollock · Paul Dijkstra · James Calder · Robin Chakraverty
Received: 25 April 2014 / Accepted: 27 October 2014 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2014
Abstract Purpose The plantaris tendon is present in 98–100 % of people, and a potential relationship between the plantaris tendon and the development of Achilles tendinopathy has been postulated. There are no studies on the epidemiology of plantaris injuries in a sporting population. This retrospective cohort study presents the incidence, nature and outcome of plantaris injuries in elite British track and field athletes. Method All 214 elite athletes supported by the British Athletics Medical team from 2009 to 2013 were included in this cohort study. An injury was recorded if a plantaris injury was diagnosed and confirmed with imaging or surgical findings. Patient demographics, injury details and return to competitive elite track and field were recorded. Results There were 33 new plantaris injuries, with an annual plantaris injury incidence of 3.9–9.3 %. There were significantly more right-sided plantaris injuries in bend running sprinters (15 right-sided vs. 4 left-sided). 74 % of the athletes who had a plantaris injury also had Achilles
N. Pollock (*) British Athletics Team Doctor, Level 1 Outpatients, Hospital of St John and St Elizabeth, 60 Grove End Road, London NW8 9NH, UK e-mail:
[email protected] P. Dijkstra Sports Medicine Department, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, PO Box 29222, Doha, Qatar J. Calder Chelsea and Westminster Hospital NHS Foundation, London, UK R. Chakraverty British Athletics Institute, Loughborough University, Loughborough, UK
tendinopathy at some point during the study period. Seventeen plantaris tendons were surgically removed from 13 athletes during the course of the study with 12 of the 13 athletes returning to the same level on the Tegner activity scale. Conclusion This retrospective cohort study demonstrates that plantaris injuries are common in elite track and field athletes and may be underreported in the literature. There may be an association between the biomechanics bend sprinting and plantaris injury. Elite athletes may benefit from appropriate preventative and management strategies implemented by coaching and medical teams. Level of evidence IV. Keywords Plantaris · Athletics · Injury · Achilles · Tendon
Introduction The plantaris originates from the posterolateral femoral condyle and traverses medially in the mid-calf, between gastrocnemius and soleus, to descend along the medial aspect of the Achilles tendon. It has a variable insertion directly into the Achilles tendon or separately into the calcaneus [27]. It has a small proximal muscle and a long thin distal tendon. Throughout the literature, it is often discussed as a vestigial structure that is absent in 8–20 % of limbs [9, 13, 18, 24]. However, more recent cadaveric studies have identified a plantaris tendon in 98–100 % of specimens [27, 21]. Therefore, the proposition that the plantaris is a vestigial or irrelevant rudimentary structure may need to be reconsidered. Complete tears of the plantaris muscle and tendon have been reported in the literature [4, 7, 11]. Rupture is
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reported to be most common at the muscle tendon junction in the upper part of the calf [4, 10, 14] but may also occur in the long thin tendon [4]. In recent years, it has been postulated that the plantaris tendon has a role in the development of mid-portion Achilles tendinopathy [1, 25, 27]. The plantaris tendon is in close proximity to the Achilles tendon, and in some cases, a retinacular like adhesion may be present [27]. The adherence or invagination of highly innervated peritendinous tissue [3, 22] to the Achilles may induce tendon region pain. Friction and traction forces may result in inflammatory change around the Achilles tendon and potentially intratendinous pathology through compression [6] or a mechanotransduction stimulus. There are a number of published surgical case series of plantaris removal [1, 19, 26] but no studies that comment on surgical and non-surgical cases of plantaris injury in a sporting population. The aim of this retrospective cohort study was to report on the incidence of plantaris injuries in a cohort of 214 elite track and field athletes who were supported by the British Athletics Medical Team over a 4-year period from 2009 to 2013. A secondary aim was to explore the nature of these injuries, including the event type, side of injury and outcome data regarding return to elite sport. The potential role of plantaris in sporting function and pathogenesis of plantaris pathology in elite track and field athletes is discussed.
Knee Surg Sports Traumatol Arthrosc
Fig. 1 MR image of complete plantaris rupture
Materials and methods All athletes supported by the British Athletics Medical Team from September 2009 to September 2013 were eligible for inclusion, and athletes with a plantaris injury were asked for consent for their record to be retrospectively analysed. Ethical approval was granted by QMUL, London. These athletes were managed by a full-time employed medical team of 3 Sports Medicine physicians and a number of physical therapists. Each athlete had competed for the Great Britain Athletics Team at an international competition (European or World Championships or Olympic Games). Each athlete had detailed electronic medical records (EMR) on the British Athletics Profiler EMR in which every injury was recorded. For this system, an injury was defined as any physical complaint sustained by an athlete that required assessment or treatment by one of three fulltime British Athletics medical doctors. A plantaris injury was included in this study if the sports medicine physician diagnosed plantaris injury in the clinical notes with, in addition, an ultrasound or MRI scan, or in-surgical findings
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Fig. 2 US axial image of complete plantaris rupture
demonstrating injury to the plantaris. The clinical diagnosis was made, and subsequent imaging undertaken, with the presentation of limitation of function by pain specifically along the medial border of the Achilles tendon. There were 3 recorded diagnoses related to the plantaris tendon in the study. A complete or partial rupture was diagnosed with an appropriate history of acute onset pain at the medial aspect of the Achilles tendon with 1.5 T or 3 T MRI and ultrasound visualisation of the complete or plantaris tear (Figs. 1, 2 and 3). A plantaris tendinopathy/plantaris friction syndrome was recorded when an athlete presented with pain at the medial aspect of the Achilles and ultrasound findings of hypoechogenicity and vascularity around the plantaris tendon or intrasubstance change within the plantaris consistent with tendinopathy was visualised on ultrasound (Fig. 4). Athlete demographics, sporting event information as well as specific information relating to the injury diagnosis,
Knee Surg Sports Traumatol Arthrosc
small medial incision as reported in the literature [2, 19]. In cases of concomitant Achilles tendon pathology, the ventral aspect of the Achilles tendon was also scraped as described in the literature [2]. Indications for surgery were failure of adequate symptom resolution with conservative management and agreement with the coach and athlete that further intervention was required to improve athletic function. A Tegner activity level scale and performance details in return to elite sport were also recorded [29]. Statistical analysis Chi-squared test was used to test for difference in limb presentation in bend running sprinters. T test was used to assess for difference in age in those athletes with additional Achilles tendon pathology. p
