The sphericity deviation score: a quantitative radiologic outcome measure of Legg-Calvé Perthes disease applicable at the stage of healing and at skeletal maturity.

Aim: This study aimed to determine if a new measure of sphericity of the femoral head, the Sphericity Deviation Score (SDS), could be estimated reliably at the stage of healing of Legg-Calvé-Perthes disease (LCPD) and to determine if the SDS at the healing stage reflects the outcome at skeletal maturity.

Methods: The SDS was measured with image analysis software on radiographs of 120 children with unilateral LCPD at healing of the disease and at skeletal maturity. The reproducibility of measurement was assessed.

Effect of prophylactic trochanteric epiphyseodesis in older children with Perthes' disease.

To evaluate the effect of prophylactic epiphyseodesis of the greater trochanter in Perthes' disease, 62 children with unilateral Perthes' disease who underwent trochanteric epiphyseodesis combined with varus osteotomy of the femur during the active stage of the disease (mean age at surgery: 8.4 y) and 20 controls were followed up until skeletal maturity. On radiographs taken at skeletal maturity, the articulo-trochanteric distance, the center-trochanteric distance, the length of the abductor lever arm, the neck-shaft angle, the radius of the femoral head, and the Reimer's migration index of normal and affected hips were measured.