Premature closure of distal fibular growth plate: a case of longitudinal syndesmosis instability

Post-traumatic premature closure of distal fibular growth plate is a rare entity and results in shortened lateral malleolus. This can lead to lateral wedging of distal tibial epiphysis, valgus ankle and medial ankle instability. Ramsey and Hamilton noted experimentally that loss of fibular length caused a dramatic lateral shift in tibiotalar surfaces. Even a displacement of as little as 1 mm will distort the areas of tibiotalar contact and lead to early joint degeneration. Colton believed it is due to the oblique articular surface of the malleolus is no longer closely applied to the talus. We present a case of premature closure of distal fibular physis with lateral malleolar shortening. Ankle arthroscopy demonstrated syndesmosis instability resulted from shortened lateral malleolus and stability restored after fibular lengthening.