Purpose: The purpose of this study was to clarify the differences in the causes of osteochondral lesions (OCL) of the ankle based on the presence of distal fibular fractures and lateral instability of the ankle.
Type of study: Case series.
Methods: We evaluated 92 cases of distal fibular fractures and 86 cases of lateral instability of the ankle, including 36 feet with subacute lateral instability of the ankle and 50 feet with chronic lateral instability of the ankle. In diagnosing OCL, we used a combination of magnetic resonance imaging to evaluate the subchondral conditions and ankle arthroscopy to evaluate the chondral conditions.
Results: Of a total of 92 distal fibular fractures, 65 cases (70.7%) had OCL at the time of osteosynthesis and 27 did not (29.3%). Among the latter group, 2 developed OCL about 1 year after surgery. Of a total of 86 cases of lateral instability of the ankle, 35 (40.7%) had OCL. Among the subacute cases, 7 of 36 (19.4%) had OCL, versus 28 of 50 cases (56.0%) with chronic lateral instability of the ankle.
Conclusions: Our study suggests that recurrent ankle sprains with remaining lateral instability and distal fibular fractures could be one of the causes of OCL of the ankle.