Medial Closing-Wedge Distal Femoral Varus Osteotomy via Lateral Approach: The Modified Technique for Treating Valgus Osteoarthritic Knee as Case Series

Abstract

Objective: The medial closing-wedge distal femoral varus osteotomy (MCW-DFVO) was an excellent operation for painful valgus lateral unicompartmental osteoarthritic (OA) knee, especially in the young patient. Originally, it requires a medial approach that has more precarious. On top of that, releasing of the iliotibial band that is the deforming force needs added incision. Therefore, this study aims to describe the modified surgical technique of MCW-DFVO that uses a lateral approach and lateral plating to treat the valgus OA knee. Additionally, we also reveal the outcomes of our technique as the case series. Materials and Methods: Ten patients (12 knees) who underwent MCW-DFVO via a lateral approach were retrospectively reviewed. The inclusion criteria were age 18-60 years, isolated lateral compartmental OA knee (Kellgren-Lawrence grade 3-4), no significant patellofemoral pain, and range of motion (ROM) > 90 degrees. We excluded the inflammatory joint disease, unstable knee (femorotibial joint subluxation > 1 cm), and prior surgical procedure. Demographic data, pre- and postoperative ROM, radiographic outcomes, complications, and survivorship were recorded. Results: The mean age, body mass index, and preoperative ROM were 55.3 ± 4.0 years, 25.4 ± 3.7 kg/m2 and 113.3 ± 11.5 degrees, respectively. The preoperative mechanical femorotibial angle was 162.3 ± 4.8 degrees, and the final post-operative alignment was 182.3 ± 2.6 degrees. Overall mean operative time of this technique was 92.5 ± 26.7 minutes. During the mean follow-up period of 8.3 ± 3.1 years, all osteotomy were united and the final postoperative ROM was decreased to 108.8 ± 11.7 degrees. One knee required plate removal due to hardware irritation, and another knee required subsequent total knee arthroplasty at 1 and 8.5 years after MCW-DFVO, respectively. The survivorship of this technique was 91.7% at the mean survival time of 13.8 years (95% confidence interval, 11.9 – 15.7 years). Conclusion: This study proposed the modified surgical technique of MCW-DFVO via a lateral approach. This technique provided the excellent correction angle, union rate and survivorship.

Keywords

• Distal femoral varus osteotomy
• medial closing wedge
• survivorship
• osteoarthritis
• knee