Role of surgery in the management of lesions of the medial collateral ligament of the ankle.

Medial ankle instability is likely underestimated. Three types of medial collateral ligament (MCL) lesion exist: isolated lesions, in case of valgus sprain in external rotation; lesions associated with chronic lateral instability, in case of rotational instability; and lesions associated with medial insufficiency and valgus flat-foot. Diagnostic confirmation and treatment of MCL lesions, isolated or associated with chronic lateral instability, by ligament suture is at present largely arthroscopic. Chronic MCL lesions with valgus flat-foot are probably irreversible: ligament reconstruction is unreliable, and bone surgery (osteotomy, fusion) is required.