Congenital distal femoral focal deficiency: report of a unique case.

An 8-year-old Chinese boy with congenital leg length discrepancy is believed to be the first reported case of unequivocal distal femoral focal deficiency. A pseudarthrosis is present between the normal appearing distal femoral epiphysis and the lower end of the femoral diaphysis. The patient's family history is negative for congenital limb deficiency, psuedarthrosis and neurofibromatosis. There is no history of trauma or infection. Congenital lack of distal femoral physis in this case is analogous to Aitken's Classification Type B proximal femoral focal deficiency.