Computerized tomography in the evaluation of peroneal tendon dislocation. A report of two cases

Dislocation or subluxation of a peroneal tendon is a relatively uncommon entity, and the diagnosis is rarely made at the time of initial injury. If untreated, chronic lateral instability and pain may develop which can be a diagnostic dilemma. These patients usually will have a history of frequent episodes of ankle instability and may be aware of a pop or snap just prior to the episode of instability. There is usually no significant anterior drawer or inversion laxity present on stress testing. Unfortunately, it is often difficult to passively or actively dislocate the involved peroneal tendon. Surgical treatment may have to be recommended on strong suspicion alone. Two patients with chronic lateral ankle pain underwent computerized tomography preoperatively and postoperatively. In addition, eight normal ankles were scanned for comparison. In the two cases of peroneal tendon dislocations presented, computerized tomography was found to be a very beneficial aid in making the diagnosis, and may be of significant value in those with suspected peroneal tendon subluxation/dislocations.