Intra-Articular Osteotomy for Genu Valgum in the Knee with a Lateral Compartment Deficiency.

Background: A deficiency of the lateral compartment of the knee, often in the setting of skeletal dysplasia, is an intra-articular deformity resulting in genu valgum. Historically, this abnormality has been treated using an extra-articular approach. Lateral hypoplasia of the femoral condyle can be treated with advancement of the lateral femoral condyle without creating a secondary deformity. The purpose of this study was to present the technique and results of lateral condylar advancement, with or without tibial hemiplateau elevation, in patients with intra-articular valgus deformity secondary to skeletal dysplasia.

Methods: A retrospective review of the cases of five patients, from seven to twenty-one years old, with skeletal dysplasia and unilateral or bilateral severe genu valgum deformity was performed. For all patients, the etiology of the deformity was a deficient lateral compartment of the knee-that is, lateral femoral condylar hypoplasia with or without concomitant lateral hemiplateau depression. Lateral femoral condylar advancement with or without lateral tibial hemiplateau elevation was performed in eight knees.

Results: The average tibiofemoral angle was 34.7° of valgus preoperatively and improved to 9.4° of valgus at the most recent follow-up. The average length of follow-up was 2.9 years (range, 1.0 to 5.2 years). The average range of motion at the time of final follow-up was an arc of 108° starting from full extension. All osteotomies healed uneventfully. All five patients were satisfied with both the cosmetic appearance and the function of the involved limb and were able to walk without assistive devices.

Conclusions: In patients with a deficient lateral compartment of the knee, lateral femoral condylar advancement with or without hemiplateau elevation allowed correction of severe genu valgum without the creation of an oblique joint line. This technique allows correction of the overall mechanical axis, restoring both function and the cosmetic appearance of the limb.

Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.