Medial closing wedge high tibial osteotomy for lateral osteoarthritis in valgus knee offers good long‐term outcomes in patients with normal body mass index

Abstract Purpose This study aimed to evaluate the long‐term functional outcomes and survivorship of medial closing wedge high tibial osteotomy (MCWHTO) in treating lateral femorotibial osteoarthritis (OA) and factors associated. Methods Between 1997 and 2018, 65 patients (67 knees) who underwent an MCWHTO were longitudinally assessed. Inclusion criteria were symptomatic lateral femorotibial OA in valgus knees with no signs of medial compartment OA. The primary outcome was osteotomy survivorship with a failure endpoint defined by the necessity for total knee arthroplasty (TKA). Clinical and functional outcomes, including Knee injury and Osteoarthritis Outcome Score (KOOS), University of California, Los Angeles (UCLA) activity scale and patient satisfaction, as well as radiological evaluation, including hip‐knee‐ankle angle (HKA), mechanical proximal tibial angle (mPTA) and mechanical lateral distal femoral angle (mLDFA), were assessed both preoperatively and at final follow‐up. Results The mean follow‐up was 11.5 ± 6.3 years [3.3–24.5]. Three patients were lost at final follow‐up. Overall, 25 (39.1%) patients progressed to TKA. Median time to TKA was 12.7 years [95% CI: 10.6–17.1]. Risk of TKA conversion before 10 years was 7.4 times higher in patients with body mass index (BMI) > 30 ( p = 0.004). Among the 39 remaining patients, significant postoperative improvements were observed in the KOOS from 40.8 ± 14.7 to 68.2 ± 19.2 ( p < 0.0001) and the UCLA activity scale from 4.6 ± 2.1 to 7.0 ± 1.8 ( p < 0.0001). Radiological evaluations showed a shift toward varus alignment (HKA: 184.5 ± 2.5 vs. 178.8 ± 2.8; p < 0.0001). There was a significant evolution of the mPTA from 89.5 ± 2.6 preoperatively to 84.0 ± 2.3 postoperatively ( p < 0.0001). There was no significant difference in the measurement of mLDFA. More than 80% of patients were very satisfied or would recommend the surgery. Conclusion MCWHTO offers reliable long‐term outcomes in valgus knees with lateral OA. Patient selection, particularly regarding BMI, is essential to achieve optimal survivorship. Level of Evidence Level IV, case series.