Relative trochanteric overgrowth after ischemic necrosis in congenital dislocation of the hip.

To determine the relative trochanteric overgrowth after ischemic necrosis of the femoral head during treatment of congenital dislocation of the hip (CDH), we reviewed radiographs of patients with ischemic necrosis and no femoral side surgery. The articulotrochanteric distance (ATD) was recorded after physeal closure. Ischemic necrosis was classified with the systems proposed by Salter et al. and Kalamchi and MacEwen. The resultant overgrowth was correlated with these systems. The articulotrochanteric distance in 29 patients with a Trendelenburg gait was also measured. The Kalamchi classification is more useful for predicting relative trochanteric overgrowth. Children with an ATD of less than or equal to 0 mm are likely to have a Trendelenburg gait.