Achilles tendon ruptures are relatively common. During the last few decades, the incidence of spontaneous ruptures has been rising, which may be due to the increasing number of people in the general population who are exercising regularly. Ruptures occur most frequently in patients (mostly male) between the ages of 30 and 50.5 Approximately 75% of Achilles tendon ruptures occur during sports activities, especially in people who play racquet games, football and handball.16
There is little agreement on the aetiology of spontaneous Achilles tendon ruptures. Several hypotheses have been proposed, such as poor tendon vascularity, the adverse effect of the use of corticosteroids and fluoroquinolones, and exercise-induced hyperthermia in a relatively avascular tendon. Mechanical factors such as overpronation of the foot on heel-strike, training errors, malfunction or suppression of propriocepsis of skeletal muscle have also been suggested. Histologically, spontaneously ruptured Achilles tendons might show degeneration of the fibres near the rupture site. There is a decrease in maximum diameter and density of collagen fibrils. There is, however, little evidence of a failed healing response. The aetiology is probably multifactorial.15
The diagnosis is generally clinical as opposed to relying on imaging studies. The mechanism of injury includes a sudden pushing off from the weight-bearing forefoot with the knee in extension, unexpected ankle dorsiflexion or violent dorsiflexion of a plantar-flexed foot. Patients report sudden intense pain in the mid-portion of the Achilles tendon, often stating that they thought someone might have struck or kicked their heel.
On clinical examination, there is a loss of the normal resting posture of the Achilles tendon. There will also be a palpable gap in the tendon. A positive calf squeeze test, the so-called Thompson test, is also seen.
If any diagnostic doubt still exists, the next step is to perform a diagnostic ultrasound of the tendon and its insertion. This can be misleading as it can be difficult to distinguish between complete and partial tendon ruptures. In these cases, MRI can be a more reliable option.
There is a lack of consensus on the best management of the Achilles tendon rupture. The key issue is to try to get the tendon to heal at its normal length. This can be done with immobilisation in an equinous position or with surgical repair. Generally, open operative management is used in elite athletes, although over the past few years percutaneous techniques have been performed more commonly. Conservative management can be a good alternative for those with co-morbidities or in patients who do not wish to have surgery. Recent systematic reviews have concluded that operative management has a lower re-rupture rate, but must be balanced by the risks associated with surgery (e.g. complications occurring in up to 30% of patients).17 Other potential drawbacks of non-operative treatment include decreased plantar flexion strength and reduced endurance when compared with patients with surgically repaired tendons.18