Avascular necrosis in the contralateral hip in patients with congenital femoral deficiency: A report of 3 cases

Background: Congenital femoral deficiency is an uncommon clinical entity. We report 3 patients who developed avascular necrosis of the hip in the long (normal) leg during longitudinal observation and/or treatment of congenital femoral deficiency. Methods: Patients were identified in limb length discrepancy clinic and their charts were retrospectively reviewed for clinical and radiographic data collection. Results: We describe the occurrence of idiopathic avascular necrosis in the normal limb in patients being followed for limb length discrepancy. Conclusions: Although no conclusion could be drawn about the etiology of the avascular necrosis, we describe a previously undocumented relationship between congenital femoral deficiency and avascular necrosis in the contralateral hip. This occurred in our congenital femoral deficiency population at a rate higher than expected compared with published incidences of avascular necrosis of the hip in children.