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. LEVEL OF EVIDENCE:: Level IV—case series.