Treatment of genu valgus deformity in congenital absence of the fibula.

Twenty patients with Syme amputation for congenital absence of the fibula and genu valgus deformity were followed until skeletal maturity. Radiographs were analyzed for genu valgus, mechanical axis, tibial angulation, and the condylar height ratio. This ratio was determined by measuring the greatest perpendicular height from the physis to the joint line and dividing the lateral height by the medial height. A smaller value represented more marked lateral condylar hypoplasia. The presence of medial tibial angulation and the degree of lateral femoral condylar hypoplasia correlated with the degree of genu valgus. Two of three patients who had proximal tibial osteotomies required multiple procedures for recurrent deformity. Medial distal femoral physeal stapling corrected the deformity in five of six limbs. The procedure is simple, allows immediate weightbearing in the prosthesis postoperatively, and has low morbidity. Patients should be followed closely until skeletal maturity. Osteotomy performed before skeletal maturity can result in recurrence of genu valgus deformity.