The Effect of Supramalleolar Osteotomy without Marrow Stimulation on Cartilage Regeneration for Medial Compartment Ankle Osteoarthritis: Second-Look Arthroscopic Evaluation of Cartilage Regeneration

Abstract

Category: Ankle Arthritis; Ankle; Arthroscopy Introduction/Purpose: The effect of supramalleolar osteotomy (SMO) without an additional bone marrow-stimulating procedure (BMSP) on articular cartilage regeneration in ankle joint still remains unknown. This study aimed to investigate whether SMO yielded favorable clinical and radiologic outcomes, and to evaluate whether the regeneration of articular cartilage could be observed after SMO without BMSP by second-look arthroscopy. Methods: 43 ankles after SMO (mean follow-up: 35.5 months) were retrospectively reviewed. Visual analog scale (VAS) pain score, American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, patient satisfaction were used for functional evaluations. The tibial anterior surface angle (TAS) and tibial lateral surface angle (TLS) were measured on radiographs, and ankle osteoarthritis was classified by Takakura stage. Among the 43 patients, 31 underwent ankle arthroscopy prior to SMO, and second-look arthroscopy was performed at 1-year postoperatively. Tibiotalar cartilage regeneration was evaluated according to the modified Outerbridge classification for the 29 patients who had undergone SMO without BMSP. Results: The mean VAS score and AOFAS score significantly improved from 6.4 preoperatively to 1.4 postoperatively and from 61.1 preoperatively to 88.4 postoperatively, respectively (P < 0.05). Regarding overall postoperative patient satisfaction, 18 (41.8%) patients reported their satisfaction as excellent, 23 (53.5%) as satisfied. The mean TAS and TLS significantly improved from 83.8° and 94.8° preoperatively to 78.4° and 82.2° postoperatively, respectively (P < 0.05). 23 out of 28 preoperative Takakura stage IIIa cases and 3 out of 7 IIIb cases improved to postoperative stage II. On second-look arthroscopy, cartilage regeneration of the medial compartment of the tibiotalar joint was observed in 26 of 29 patients (89.7%), whereas cartilage deterioration was not observed in any patient. Conclusion: Medial tibio-talar articular cartilage regeneration was observed in most cases (89.7%) of medial compartment ankle osteoarthritis after SMO without BMSP, which was confirmed with second-look arthroscopic evaluation. It also showed satisfactory clinical and radiologic outcomes with high patient satisfaction.