The effect of lateral opening wedge distal femoral osteotomy on leg length.

Objective: Varisation distal femoral osteotomy is a well-described treatment for lateral compartment arthrosis in the young, active patient. This treatment may potentially alter the length of the lower limb . The objective of this study was to quantify the change in leg length following lateral opening wedge distal femoral osteotomy using a blade plate.

Methods: Between 1998 and 2011, 29 lateral opening wedge distal femoral osteotomies were performed for symptomatic genu valgum with signs of lateral compartment arthrosis or patello-femoral symptoms. The mean age was 44.4 years (±11.3). Average follow-up was 80.2 months (±50.6).

Results: The mean osteotomy opening was 8.3° (±2.3). The femoro-tibial mechanical axis (mFTA) was improved significantly, from 187.8° (±3.5) to 180.4° (±2.6) post-operatively (p < 0.001). The pre-operative leg length discrepancy was -0.7 cm, compared to -0.6 cm post-operatively, which was not significant (n.s.). There were five revisions to arthroplasty for disease progression at meantime of 166.6 months post-operatively. The probability of survival at 60 months was 91.4% (95% CI 74.9-100%) with end-point of revision to total knee arthroplasty and 87.6% (95% CI 74.1-100%) of revision for complications.

Conclusions: Lateral opening wedge distal femoral osteotomy, performed for symptomatic genu valgum, has no effect on leg length. This technique allows good correction of the axis of the lower limb; however, the complication rate is not insignificant (14%). Complications occurred mainly in post-traumatic cases and may be avoidable with attention to technique and optimum rehabilitation. The procedure should be reserved for young, active patients with significant symptoms. Methods: IV.