Idiopathic genu valgum treated by epiphyseodesis in adolescence

Twenty-three patients (13 boys and 10 girls) with the adolescent type of genu valgum were treated by temporary medial epiphyseodesis of both distal femurs with Blount staples (46 knees); 5 also underwent stapling of the proximal tibia. Evaluation before the operation and during the follow up was based on growth charts, photographs and measurement of the intermalleolar distance. The indication for operation was increasing genu valgum with 10 cm or more of intermalleolar separation; the median distance before operation was 13 cm for boys and 12 cm for girls. The staples were removed after a median time of 11 months. At skeletal maturity the median intermalleolar separation was 3 cm for boys and 2 cm for girls. The median frontal angle before operation was 14 degrees for boys and 6 degrees at follow up, the corresponding figures for girls being 14 degrees and 4 degrees. In 2 cases the deformity recurred because the staples were removed too early. In another case a bony bridge formed after the staple was removed and a varus deformity developed; the bridge was resected and the knees became valgus again, but 1 cm of shortening remained on one side. There were no other complications.