Ten‐year minimal follow‐up of lateral opening wedge distal femoral osteotomy for lateral femorotibial osteoarthritis: Good survivorship and high patient satisfaction

Purpose This study aimed (1) to determine complications and survival rates of lateral opening wedge distal femoral osteotomy (LOW‐DFO) in the long term, (2) to assess their clinical outcomes in the long term and (3) to identify risk factors of failure. Methods Between 1991 and 2011, 62 LOW‐DFOs were performed in the same department. Inclusion criteria were all isolated LOW‐DFO performed for isolated lateral tibiofemoral osteoarthritis and valgus malalignment, with a minimum 10‐year follow‐up. Thirty‐eight patients were included, with a mean age of 48 ± 9 years. All patients had clinical and radiological assessments. The survival curves were calculated based on the following endpoints: unicompartmental or total knee arthroplasty. Results The mean follow‐up was 15.2 ± 4.4 [10–29] years. The mean preoperative mechanical FemoroTibial Axis (mFTA) was 188.8° ± 3.2° [184°–197°], primarily due to femur deformity (mean lateral distal femoral axis [LDFA] 83.2° ± 2.8°). Bone union was achieved in 89.5% of patients ( n = 34) at a mean delay of 6.5 ± 6.7 months. The complication rate was 26% (five stiffness, one nonunion, three secondary displacements and one deep vein thrombosis). Nine revision surgeries (24%) were recorded. Survival rates at 5 and 10 years were 92.1% and 78.9%, respectively. The mean delay between DFO and total knee arthroplasty (TKA) was 11.6 ± 5.7 [1–27] years. Nineteen patients (50%) were free of TKA at the last follow‐up. KSS scores were improved significantly. Return to sports was obtained in 92% of cases ( n = 35), with a mean delay of 11 ± 8 months. Seventy‐four per cent of patients were satisfied or very satisfied with the surgery. Eighty‐four per cent would be willing to undergo the surgery again. Older age ( p = 0.032) was a significant risk factor for TKA conversion. Conclusion LOW‐DFO is an efficient procedure to manage lateral knee osteoarthritis in young patients with valgus deformity, with a good survival rate at 10 years and high patient satisfaction. Level of Evidence Level III.