FOCUS | CLINICAL The Achilles tendon Management of acute and chronic conditions Amy Touzell THE GASTROCNEMIUS AND SOLEUS MUSCLES, highly important for walking, running and impact activities, fuse to form the Achilles tendon, which is the largest and strongest tendon in the body.1 The Background The prevalence of acute and chronic conditions of the tendon needs to withstand up to eight times body weight in force when 2 Achilles tendon is increasing among an ageing, active undertaking sporting activities, and injuries to the Achilles tendon population. These conditions are a common cause of are common. Incidence and prevalence of Achilles tendon injuries has presentation to general practitioners and allied health increased in the past 30 years, thought to be due to a combination of practitioners. Achilles tendon injuries have a bimodal an active, ageing population and increased participation in sport and demographical presentation, with acute injuries exercise programs in general.3 commonly occurring in younger people and chronic Achilles tendon injuries can be divided into acute ruptures and conditions presenting in patients who are elderly. chronic overuse injuries. Both can be debilitating, with significant Objective morbidity for patients; fortunately, both types of injuries respond The aims of this article are to discuss management well to non-operative and operative interventions, and only a small of acute Achilles tendon ruptures in the primary care proportion requiring surgical intervention. setting, explain the risks associated with calcaneal tuberosity fracture and discuss non-operative and surgical management of acute and chronic overload conditions of the Achilles tendon. Acute rupture Acute rupture of the Achilles tendon is a common injury, accounting for Discussion 20% of all large tendon ruptures. The estimated incidence ranges from Achilles tendon injuries can be divided into acute ruptures and chronic overuse injuries. Both can be 11 to 37 per 100,000 population, with men more than twice as likely to 4 debilitating, with significant morbidity for patients; rupture their Achilles tendon than women. This injury has a bimodal fortunately, both types of injuries respond well to non- distribution, with the first peak occurring in people aged 25–40 years operative interventions, with only a small proportion who are participating in high-energy sports, and the second peak in requiring surgery. Management of acute Achilles tendon people aged >60 years. This second peak in more elderly patients is rupture has evolved, with increasing evidence that non- commonly associated with a low-energy injury, such as getting up from operative management is appropriate providing patients a seated position, after a history of Achilles pain. The risk of rerupture participate in a functional rehabilitation protocol. Chronic conditions such as the sequalae of an untreated rupture is higher in elderly patients with a degenerative tendon because of the or Achilles tendinopathy can be debilitating but often inherent poor quality and diminished vascular supply of the tendon respond well to non-operative management. fibres.5 In the younger population, histological studies performed on acute Achilles tendon ruptures have shown clear degenerative changes despite little or no symptoms pre-injury.6 Patients who sustain an acute Achilles tendon rupture often describe a ‘gunshot’ sensation to the back of the leg. In the younger population with sports-associated Achilles tendon ruptures, up to 90% of cases are related to an acceleration–deceleration mechanism.7 Despite the © The Royal Australian College of General Practitioners 2020 REPRINTED FROM AJGP VOL. 49, NO. 11, NOVEMBER 2020 | 715 FOCUS | CLINICAL THE ACHILLES TENDON characteristic history and symptoms, it is Differential diagnoses that warrant with clinical symptoms should be made, often a missed injury, with up to 25% of exclusion include ankle fracture, ankle as chronic changes can be reported as a cases misdiagnosed at initial presentation.8 sprain or chronic tendinopathy to the long degenerative or partial tear of the tendon. Fluoroquinolone antibiotics (commonly tendons at the back of the ankle. A careful It has been shown that ultrasonography is ciprofloxacin) have a known association history to ascertain the mechanism of more effective than magnetic resonance with Achilles tendinitis and rupture, injury combined with clinical examination imaging (MRI) for dynamically identifying with a latency period of between two can help exclude these injuries. It is the location of a tear or measuring the and 60 days. Patients aged >60 years are important that an avulsion fracture of gap between the torn tendon edges, and more likely to develop fluoroquinolone- the calcaneal tuberosity (Figure 2) is not differentiating between a partial and induced tendinitis.9 Other risk factors inadvertently diagnosed as an Achilles complete rupture.13 Therefore, MRI is not include rheumatoid arthritis, gout, tendon rupture. These fractures commonly routinely used as a diagnostic tool for an ankylosing spondylitis, chronic uraemia occur in elderly patients with diabetes, acute rupture in this author’s practice. and hyperparathyroidism, although these patients taking immunosuppressive Management of acute Achilles tendon conditions are only responsible for Achilles medication or those with a history of ruptures continues to be debated, but tendon ruptures in <2% of cases.1 osteopaenia.12 During examination, if there is emerging evidence that supervised To enable examination of a potential palpation of the Achilles tendon yields non-operative management results in very rupture of the Achilles tendon, the patient a bony lump or there is evidence of skin good outcomes. A randomised controlled should be in the prone position or kneeling tension, the patient should be placed in a trial of 144 patients randomised to on a chair so the area can be easily plantarflexed cast and an urgent X-ray of operative and non-operative intervention inspected for bruising or other skin changes. the ankle ordered. This injury is a surgical reported no clinically important difference The physical examination for detection of emergency because of the risk of skin between groups with regard to strength, an acute Achilles tendon rupture has been necrosis as the bony fragment causes range of motion or calf circumference described as ‘Simmonds’ triad’:10 tension on the overlying skin. two years post-injury.14 The authors also • Look at the angle of declination of the foot If there is any doubt regarding the reported a wound complication rate of 15% in comparison to the contralateral side. diagnosis, ultrasonography of the Achilles in the operative group. A Cochrane review • Feel for a palpable gap. tendon is useful to confirm examination reported a higher rerupture rate of 12% • Move (‘squeeze test’) – this involves a findings. It is recommended that with non-operative treatment, compared gentle squeeze of the calf with the foot clinical findings are communicated to with 5% in patients who receive surgery, hanging off the edge of the bed. If there the reporting radiologist via a detailed but a complication rate of 30% in patients is no movement of the foot, the test is referral form, specifying whether the who receive surgery, compared with 8% positive, suggesting disruption of the concern is an acute or chronic condition, in non-operatively treated patients.15 gastrocnemius-soleus complex (Figure 1). and patients are referred to centres To reduce the risk of functional The presence of two of the three signs has with ultrasonographers and radiologists lengthening (in which the tendon heals in been shown to be 100% sensitive for an experienced in musculoskeletal an elongated position causing long-term acute Achilles tendon rupture.11 ultrasonography. Careful correlation weakness), patients need to be placed in a Figure 1. Demonstration of a negative Simmonds’ squeeze test (no rupture evident) Figure 2. Calcaneal tuberosity fracture 716 | REPRINTED FROM AJGP VOL. 49, NO. 11, NOVEMBER 2020 © The Royal Australian College of General Practitioners 2020 THE ACHILLES TENDON FOCUS | CLINICAL plantarflexed cast, backslab or removable Tendinopathy and functional made, if a podiatrist or physiotherapist orthosis with a heel wedge to force the ankle lengthening of the Achilles tendon is not available, and many rural or into plantarflexion as early as possible.5 The term ‘Achilles tendinopathy’ regional exercise physiologists work in Common removable orthoses include encompasses a variety of pathologies conjunction with a remote allied health a controlled ankle motion (CAM) boot characterised by pain and swelling in and team. Patients can access a chronic disease (Figure 3). Ideally the patient is placed in a around the Achilles tendon. Tendinopathy management plan under the Medicare cast or boot in the emergency department can have an acute or insidious onset. Benefits Schedule if the condition has setting within hours of the injury occurring. Achilles tendon overuse injuries are been present for >6 months. Most public A referral to the local public hospital common in runners, with an annual hospital outpatient physiotherapy and fracture clinic or orthopaedic surgeon incidence of between 7% and 9% in podiatry departments also accept referrals should be made as soon as possible after high-level runners.18 Notable short-term for Achilles tendinopathy and related the injury so appropriate management improvements have been seen with conditions. Early