Supramalleolar osteotomy for the treatment of ankle osteoarthritis leads to favourable outcomes and low complication rates at mid-term follow-up: a systematic review

Purpose The purpose of this systematic review was to evaluate both the clinical and radiographic outcomes following supramalleolar osteotomy (SMO) in patients with ankle osteoarthritis, and to analyse the level of evidence (LOE) and quality of evidence (QOE) of the included studies. Methods A systematic review of the MEDLINE, EMBASE, and Cochrane Library databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting clinical data following SMO for the treatment of ankle osteoarthritis were included and assessed. The level and quality of evidence of the included studies were also evaluated. Results Twenty-four studies with 1160 patients (1182 ankles) were included. Overall, 78.8% patients presented with post-traumatic ankle osteoarthritis. The weighted mean AOFAS score improved from 52.6 +/- 9.7 (range 33.8-78.4) preoperatively to 78.1 +/- 5.7 postoperatively at weighted mean follow-up of 50.4 +/- 18.6 months (range 24.5-99.0). The most frequently utilised radiographic parameter was the tibial anterior surface angle, which improved from a preoperative weighted mean of 86.3 degrees +/- 5.6 degrees (range 76.0 degrees-102.0 degrees) to a postoperative weighted mean of 89.9 degrees +/- 3.7 degrees (range 84.9 degrees-99.6 degrees). The complication rate was 5.1% with non-union as the most commonly reported complication (1.6%). Secondary procedures were carried out in 28.2% of patients, the most common of which was implant and hardware removal (17.6%). The failure rate was 6.8%. Two studies were LOE II, 3 studies were LOE III, and 19 studies were LOE IV. The mean Modified Coleman Methodology Score was 59.3 +/- 6.6 and the mean MINORS criteria score of all the included studies was 9.5 +/- 3.7. Conclusion This systematic review demonstrates good clinical and radiological outcomes, together with a low failure rate at mid-term follow-up following supramalleolar osteotomy in patients with ankle osteoarthritis. However, a moderate reoperation rate (28.2%) was reported. A low failure rate (6.8%) was reported, which must be interpreted in light of the shortcomings of the design of the included studies and a relatively short follow-up period. In addition, there is a low level and quality of evidence in the current literature with inconsistent reporting of data which underscores the need for further higher quality research to be conducted. Our review highlights that SMO may be an effective and safe procedure in the setting of early-to-intermediate-stage ankle osteoarthritis.