Chronic ankle joint instability: in unrecognized distal rupture of the syndosmosis and malunion of the distal fibula

Background: It is often difficult in the acute phase to diagnose a lesion of the distal tibiofibular syndesmosis. If this lesion is overlooked, the patient will develop an incongruity of the upper ankle joint with a pathological external rotation of the talus. The risk of a possible premature arthritis is clearly increased.

Objective: In this case study a distal rupture of the syndesmosis in a young patient was overlooked in the initial diagnostic work-up.

Methods: A search of the relevant literature and a case report.

Results: In the case described the shortened fibula and chronic instability of the tibiofibular syndesmosis were repaired with a lengthening and derotational osteotomy and reconstruction using the gracilis muscle tendon. Through this method an exact reconstruction of the normal anatomy could be achieved.

Conclusions: Posttraumatic misalignment in the ankle joint is associated with a high risk of secondary degenerative lesions. In cases with suspicion of a syndesmosis lesion, confirmation of the diagnosis is imperative so as to perform an anatomic repositioning and reconstruction of stability.