PurposeThe purpose of this retrospective study was to assess the treatment of post-traumatic osteochondral lesions (OCLs) of the ankle with a four-step protocol.MethodsThirty-eight patients with at least one MRI-documented OCL of the ankle were treated from 2004 to 2010. Median age at surgery was 39 years (range: 18–52). Mean lesion size was 1.0 cm2 (SD: 0.2). All patients underwent a four-step surgical procedure including synovectomy, debridement and microfractures of the OCL, capsular shrinkage, and bracing and non-weightbearing for 21 days. Clinical assessment included objective examination, the AOFAS ankle and hindfoot scoring system, Karlsson-Peterson score, Tegner activity level, and Sefton articular stability scale. MRI scans were taken 18 months after surgery in all patients.ResultsFollow-up examination at an average of 4 years (SD: 1.1) after surgery showed significant improvement of all variables compared to pre-operative values (P < 0.05). Most patients rated their outcome as good/excellent. MRI scans taken 18 months after surgery documented completely repaired lesion in 27 ankles, slight bone marrow oedema with partially repaired defect in 9 patients, and visible defect in 2 ankles.ConclusionBased on the present results, we propose a comprehensive four-step protocol as a safe and clinically effective treatment option in patients with post-traumatic OCLs of the ankle.Level of evidenceRetrospective case series, Level IV.