Clinical application of different types supramalleolar osteotomy for varus ankle osteoarthritis

Abstract

Objective To evaluate the anatomical variations and clinical application of supramalleolar osteotomy(SMOT). Methods From April 2012 to April 2016, 54 mid-staged varus ankle osteoarthritis patients were treated with SMOT and followed at least one year were included. Among them, 27 patients received traditional ankle osteotomy, 21 patients received oblique ankle osteotomy, and 6 patients received intra-articular osteotouly. Twenty-two males and 32 females with a mean age of 56.5 (range, 32-67) years. According to the modified Takakura ankle osteoarthritis stage, there were 11 stage-2, 29 stage-3A and 14 stage-3B. The American orthopedic foot and ankle society (AOFAS) ankle-hind score and Ankle Osteoarthritis Scale (AOS) were used for pre- and postoperative functional evaluation. The tibial anterior surface angle (TAS), talar tilt (TT), tibiocrural angle (TC), tibial medial malleolus angle (TMM), and tibial lateral surface angle (TLS) were evaluated pre- and postoperatively. Results The mean follow-up time was 34.9 (range, 14-65) months. Two cases with postoperative pain and dysfunction were treated with ankle fusion. At last follow-up time, the mean AOFAS score was improved (54.6±14.2 vs. 83.7±9.8, P<0.01). The mean AOS pain(43.6±6.4 vs. 26.6±5.2) and function scores(52.7±11.3 vs. 35.4±10.3) were decreased (all P values<0.01). For radiological evaluation, all of included parameters were improved (P<0.01) except TLS. The mean Takakura stage was improved in 59% (32/54) of cases. Of the 9 cases with preoperative TT≥10°, 7 cases were corrected to normal. Conclusions According to the anatomical characters of varus ankle OA, selection of different types of SMOT, also combined with appropriate joint stable procedures can reach promising clinical outcomes. Key words: Osteoarthritis; Ankle joint; Bone malalignment; Osteotomy