Coxa vara in spina bifida.

In spina bifida the femoral neck can develop either the well-known coxa valga or the hitherto unreported coxa vara. Twenty-three cases of coxa vara in spina bifida are reported. These result from spontaneous separation of the upper femoral epiphysis (10 cases), spontaneous fracture of the femoral neck (three cases) and iatrogenic avascular necrosis of the upper femoral epiphysis (10 cases).