Patient-Specific Instrument Guided Double Chevron-Cut Distal Femur Osteotomy.

Yen-Chun Huang,Kuan-Yu Lin,Kuan-Jung Chen,Oscar Kuang-Sheng Lee,Jesse Chieh-Szu Yang

doi:10.3390/jpm11100959

Abstract

The risk of non-union and prolonged periods of protected weight-bearing still remain unsolved issues after distal femur osteotomy (DFO). To improve the stability, we developed the double chevron-cut technique, which is a modified medial closing-wedge DFO guided by a patient-specific instrument. The purpose of this study was to investigate the feasibility and outcome of this operative approach. Twenty-five knees in twenty-three consecutive patients with genu valgum and lateral compartment osteoarthritis that received double chevron-cut DFO were included. The target of correction was 50% on the weight-bearing line (WBL) ratio. Patient-reported outcomes included the Oxford Knee Score (OKS) and the 2011 Knee Society Score (KSS). The mean of the WBL ratio was corrected from 78.7% ± 12.0% to 48.7% ± 2.9% postoperatively. The mean time to full weight bearing was 3.7 ± 1.4 weeks. Union of the osteotomy was achieved at 11.3 ± 2.8 weeks. At a mean follow-up of 17 months, the OKS improved from a mean of 27.6 ± 11.7 to 39.1 ± 7.5 (p = 0.03), and the KSS from a mean of 92.1 ± 13.0 to 143.9 ± 10.2 (p < 0.001). Three patients developed complications, including one case of peri-implant fracture, one of loss of fixation, and one of non-union. The double chevron-cut DFO followed by immediate weight-bearing as tolerated is effective in treating genu valgum deformity and associated lateral compartment osteoarthritis.

Highlights

Distal femur osteotomy (DFO) has become increasingly popular in treating patients with genu valgum deformity and associated lateral compartment osteoarthritis
Genu valgum deformity can be corrected with high tibial osteotomy, deformity greater than 10◦ would be better corrected with DFO to avoid iatrogenic joint line obliquity [1,2]
Survival rates after the two procedures are similar, medial closing-wedge DFO offers the advantage of native bone-to-bone healing and inherent stability, and an earlier start of weight-bearing activities [3,4]

Summary

Introduction

Distal femur osteotomy (DFO) has become increasingly popular in treating patients with genu valgum deformity and associated lateral compartment osteoarthritis. Genu valgum deformity can be corrected with high tibial osteotomy, deformity greater than 10◦ would be better corrected with DFO to avoid iatrogenic joint line obliquity [1,2]. The valgus correction with DFO can be performed with either a medial closing-wedge or lateral open-wedge technique. Survival rates after the two procedures are similar, medial closing-wedge DFO offers the advantage of native bone-to-bone healing and inherent stability, and an earlier start of weight-bearing activities [3,4]. The conventional closing-wedge technique is troubled with 3–25% delayed union or nonunion, 5% loss of correction, and malrotated correction [5,6,7,8]. The rate of delayed union or non-union hovered around 4–5%, even with the advent of locking plates [8,9]

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