SYMPTOMS There is a severe sharp pain around the anterior tibio fibula junction, haemarthrosis and sense of ankle instability after a severe hyperflexion-inversion or eversion ankle sprain. A player cannot continue and will limp off the pitch. This injury is well-known in association with a fracture but occurs frequently in isolation in contact sports such as football and rugby.
AETIOLOGY There is an anterior, mid and posterior portion of the syndesmosis ligament, the mid-portion being the interosseous membrane. All these structures can be damaged individually or in combination. Even though these injuries are fairly rare they must not be missed. CLINICAL FINDINGS There is tenderness on palpation over the anterior syndesmosis ligament and bruising/swelling-haemarthrosis. There is an increased laxity which is sometimes mistaken for positive anterior drawer and talar tilt tests. Perform a forced dorsi-flexion and eversion while palpating the anterior syndesmosis. Pain indicates a positive syndesmosis test and a tear
Fig. 44 If a forceful dorsiflexion and eversion of the ankle causes pain over the anterior syndesmosis that is palpated, it indicates injury to this very important stabiliser of the ligament. If there is a complete tear of the three structures, the fibula can be translated both anteriorly and posteriorly without resistance holding fibula between the thumb and index finger.
INVESTIGATIONS X-ray is often normal unless taken in the weight-bearing position when there is a complete rupture of all three components. MRI may show localised oedema and effusion over the syndesmosis ligament but as a static examination it cannot fully show the extent of the instability that this injury causes. Clinical findings are most import.
TREATMENT In the acute phase RICE and nonweight bearing is advocated until the full extent of the injury is defined. A non-weight-bearing boot or crutches with non-weight-bearing should be used. In partial ruptures, proprioceptive training and partial weight-bearing exercises are often allowed after four to six weeks. Rehabilitation is usually curative
in mild cases and the athlete can resume sport within eight to twelve weeks, using a brace or strapping during the first weeks. In complete ruptures and multi-ligament injuries, surgery to stabilise the ligament, followed by a few weeks immobilisation, is usually necessary. In such cases six months absence from sport can be expected. REFERRALS Refer to orthopaedic surgeon as soon as possible after the injury for consideration of surgery.
EXERCISE PRESCRIPTION Since non-weight bearing is advocated for a long period, exercise should focus on general low-impact fitness training until healed.
Fig. 46 This is a weight-bearing X-ray of a missed syndesmosis ligament tear causing severe dysfunction and pain two years after injury, requiring major reconstructive surgery
Monitor decrease of clinical symptoms and signs and negative laxity tests. At the end of rehabilitation core stability and functional ankle tests must be done before resuming full sport. DIFFERENTIAL DIAGNOSES Fracture (X-ray will exclude).
PROGNOSIS Excellent-Good if appropriate treatment is given but long-term consequences can be dire if the diagnosis is missed.
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