The Effect of Supramalleolar Osteotomy without Marrow Stimulation for Medial Ankle Osteoarthritis Second-Look Arthroscopic Evaluation of 29 Ankles

Background: The effect of supramalleolar osteotomy without a bone marrow-stimulating procedure for articular cartilage regeneration in the ankle joint remains unknown. We investigated whether supramalleolar osteotomy yielded favorable clinical and radiographic outcomes. We also evaluated the joint tissue appearance after supramalleolar osteotomy without a bone marrow-stimulating procedure with use of second-look arthroscopy and its correlation with the outcome. Methods: Twenty-nine ankles were retrospectively reviewed at a mean of 2.9 years after supramalleolar osteotomy without a bone marrow-stimulating procedure. All 29 ankles had had second-look arthroscopy to evaluate tibiotalar joint tissue regeneration at a minimum of 1 year postoperatively. A visual analog scale (VAS) pain score, the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, and patient satisfaction were used for functional evaluations. Ankle osteoarthritis was classified with the Takakura staging system, and the tibial anterior surface (TAS) angle and tibial lateral surface (TLS) angle were measured on radiographs. Results: The mean VAS and AOFAS scores improved from 6.2 (95% confidence interval [CI], 5.7 to 6.8) preoperatively to 1.5 (95% CI, 0.9 to 2.1) postoperatively and from 60.5 (95% CI, 54.9 to 66.1) preoperatively to 88.3 (95% CI, 84.3 to 92.3) postoperatively, respectively. Patient satisfaction with the outcome of the procedure was classified as very satisfied or satisfied for 27 ankles (93.1%). Sixteen of 21 ankles that were classified as Takakura stage-IIIa and 2 of 3 ankles that were classified as stage-IIIb preoperatively improved to stage II postoperatively. The mean TAS and TLS angles significantly improved from 83.5 degrees (95% CI, 82.2 degrees to 84.7 degrees) and 77.0 degrees (95% CI, 75.4 degrees to 78.7 degrees) preoperatively to 94.2 degrees (95% CI, 92.7 degrees to 95.7 degrees) and 80.4 degrees (95% CI, 78.3 degrees to 82.5 degrees) postoperatively, respectively. On second-look arthroscopy, 26 ankles (89.7%) showed tissue regeneration of the medial compartment of the ankle joint and no patient showed cartilage deterioration. Conclusions: Medial tibiotalar tissue regeneration was identified in most patients with medial compartment ankle osteoarthritis following supramalleolar osteotomy without a bone marrow-stimulating procedure. The procedure results in satisfactory clinical and radiographic outcomes with high patient satisfaction.