Containment of the femoral head in Legg-Calvé-Perthes' disease and its prognostic significance.

The treatment of LCPD employs to an increasing degree the containment principle, in the form of femoral osteotomy, based on the hypothesis that the factor decisive for the prognosis is centralization of the femoral head, and not relief of weight-bearing by the hip. A follow-up of 48 unilateral LCPD hips treated by strict bed-rest showed a poor correlation (best value r=-0.385) between the degree of lateralization of the femoral head (the migration percentage) during the course of the disease and the spherical quotient at follow-up 12.6 years after the onset of the disease. The results reported, such as shortening of the fragmentation phase and a not unequivocally good outcome of intertrochanteric femoral osteotomy in hips "at risk", may therefore not be due to the containment principle, but perhaps to an improved venous drainage from the femoral head.