Knee Osteoarthritis Progression after Distal Femur Closing Wedge Osteotomy

Background: Despite the conservative treatment of tibio-femoral osteoarthritis through realignment osteotomies, the rate of total knee replacements following an osteotomy is increasing. The aim of this study was to identify the factors associated with the progression of knee osteoarthritis after a medial closing-wedge distal femoral osteotomy. Methods: Hospital-based observational study on 20 patients who underwent a medial closing-wedge distal femoral osteotomy evaluating the progression of osteoarthritis using the Kellgren and Laurence classification. The Wilcoxon test was used to compare the variation in the progressive stage of the Kellgren and Laurence classification of knee osteoarthritis preoperatively and at the final follow up. Univariate analysis made it possible to determine the factors associated with progression. The final significance threshold for statistical tests was set at 5% (p < 0.05). Results: Overall, the mean follow-up of 46 months ± 6.6 months, with a mean age of 43 years (range: 27 - 69 years) and a female predominance (M: F = 3/7). The progression of tibiofemoral osteoarthritis following a medial closing-wedge distal femoral osteotomy is associated with valgus or varum malalignment been a moderate valgus (OR 6.2 [1.5 - 42.7] at 95% CI; p-value = 0.02), a correction of the mechanical deviation angle with a valgus alignment (OR 2.7 [0.9 - 8.3] at 95% CI), and loss of correction (OR 3.8 [1.3 - 11.6] at 95% CI; p -value) for the lateral compartment while varus alignment (OR 1.7 [0.9 - 8.3] 95% CI, p-value = 0.05) and with rupture of the lateral cortex (OR 2.8 [1.7 - 11.5] 95% CI, p-value = 0.02) were those of the medial compartment. Conclusion: Distal femur closing wedge osteotomy does not definitively interrupt the progression of valgus knee osteoarthritis. The factors associated with the progression of this pathology are modifiable. Taking them into account when performing this surgical technique could improve the osteotomy survival curve.