Medial physeal stapling for primary and secondary genu valgum in late childhood and adolescence

We report the results of medial physeal stapling in 16 knees with primary genu valgum and 27 with secondary genu valgum. In the primary group, stapling was undertaken at a mean chronological age of 12 years in girls and 13 years in boys. The medial femoral physis was stapled in ten knees and the medial femoral and tibial physes in six knees. At skeletal maturity, all patients had excellent or good leg alignment. Secondary genu valgum is due to skeletal dysplasia, haematological or endocrine disorders, or to juvenile chronic arthritis. Stapling was at a mean chronological age of 11 years in girls and 14 years in boys. The medial femoral physis was stapled in 13 knees, the medial tibial physis in three and both in 11 knees. At skeletal maturity, 85% had excellent or good leg alignment, and correction had occurred within one year. Two of the poor results were due to staple extrusion from osteoporotic bone, and two to overcorrection. Rebound growth was minimal and unpredictable after the removal of staples. Medial physeal stapling is a suitable method of treatment for both primary and secondary genu valgum in late childhood and in adolescence. At least one year of knee growth is required to achieve correction, and care is needed to avoid overcorrection of the secondary genu valgum.