Ankle

Ankle sprains are one of the most common sporting injuries requiring treatment. The mechanism is usually inversion damaging the anterior talofibular (ATF) and subsequently the calcaneofibular (CF) ligaments (Fig. 29.8). Surgery to repair the ligaments is rarely required; functional bracing with early weight-bearing allows the ligaments to heal whilst main­taining ankle motion.

If the recovery after ankle sprain is slow then chondral damage to the talar dome should be suspected. Bone scintigraphy is the most sensitive investigation and lesions can be treated with arthroscopic débridement.

Recurrent lateral instability of the ankle requires a rehabilitation programme concentrating on restoration of proprio­ception but if this fails then repair is indicated. A direct repair of the ligament ends is usually possible, otherwise the use of a periosteal flap from the fibula or a free hamstring autograft may be used to reconstruct both the ATF and the CF liga­ments. The use of some or all of the peroneal tendons for reconstruction is best avoided as they are the dynamic stabilisers to inversion.

Posterior impingement of the ankle is practically an occu­pational hazard in ballet dancers. With the ankle in point (forced plantar flexion) the posterior malleolus, the talus and the calcaneum compress the soft tissues causing inflamma­tion. An os trigonum may or may not be present, but the diagnosis is made by reproducing the pain of impingement. With the patient prone, plantarflex the ankle and compress the heel whilst moving the forefoot from side to side. Treat­ment is surgical resection of the soft tissue, or os trigonum if present, via a short medial approach.

Repeated trauma to the anterior joint capsule causes anterior osteophytes (‘footballer’s ankle’) which limit dorsiflexion. These may be resected via the arthroscope.

Forced eversion of the ankle may disrupt the sheath sur­rounding the peroneal tendons allowing them to subluxed anteriorly. The athlete reports a ‘snapping’ sensation with activity and resisted eversion demonstrates the abnormality. Splints are ineffective at keeping the tendons in place so surgery is required to repair the defect in the sheath, supplementing it with a periosteal flap.

Ruptured tendoachilles

Rupture of the tendo achilles (TA) most commonly occurs in patients in their 40s who experience a sharp snap while run­ning or jumping. Over 80 per cent occur during sport, and the athlete describes a feeling of being struck in the back of the heel. On examination there is tenderness and swelling over the TA and careful palpation may reveal a dent in the TA, especially if it is compared with the other side. Paradoxically the patient may still be able to stand using their long toe flexors, although it may be painful. Simmons’ test involves lying the patient face down on the couch with their feet hanging over the edge of the bed. If the calves are squeezed the foot on the normal side plantar flexes but if the TA is ruptured there is no movement. This test is pathognomic of ruptured TA.

Management

If the tear is at the musculotendon junction high up in the calf then treatment only needs to be symptomatic, but if it is in the middle of the substance of the tendon then the two ends must be brought into close apposition for healing to occur. This can be done by managing the patient in a below-knee plaster with the ankle in full equinus. Serial plasters are may be used to bring the foot up into neutral. After a total of 6—8 weeks the leg is taken out of plaster and mobilisation of the ankle is started. Surgery to appose the tendon ends may be performed through a longitudinal medial incision (open) or via stab wounds (percutaneous) (Fig. 29.9). Accelerated rehabilitation regimes with functional braces are now commonly used. Ankle mobilisation starting 7 days after repair and 3-4 weeks after nonsurgical treatment lowers the re-rupture rate and maintains better muscle function.

Nonsurgical treatment has a re-rupture rate of 6—10 per cent, open repair risks wound breakdown (1—2 per cent) which is a disaster, and percutaneous repair may lead to sural nerve injury. The results of the few prospective randomised trials have unfortunately been inconclusive, so surgeons should stick to what works best for them.