Etiology of the bifid (double) femoral head, with prior history of developmental dysplasia of the hip

Our patient presented with a double femoral head, that is, two separate heads with individual epiphyses, but a single contiguous metaphysis. Two similar cases had been described in the literature. The only common feature in these three cases is that they had open reduction for Developmental Dysplasia of the Hip (DDH) through an anterior approach. No other pathology was detected in these patients. A rabbit model was created in which the cartilaginous anlage of the rabbit femoral head was surgically split. After 2 4 weeks a bifid femoral head developed, mimicking that described in the literature. We suggest that inadvertent damage to the femoral head during surgery for DDH may in fact lead to the development of a bifid femoral head. Prior history of DDH should be considered when the isolated bifid femoral head is identified.