Clinical and Experimental Study of Residual Shortening after Legg-Calve-Perthes Disease - Focused on the Causative Factors
SM Rowe, TR Yoon, ST Jung, JJ Lee
Department of Orthopedics, Chonnam National University Hospital, Kwangju, Korea

Introduction: Shortening of the affected limb has frequently been observed in children with Legg-Calvé-Perthes disease (LCPD). Many factors have been thought as the cause of residual shortening after LCPD. But, there has been no clear answer regarding which is more responsible for the residual shortening between coxa plana and disturbed physeal growth. To clear the main cause of residual shortening, we made clinical and experimental study.

Materials and Methods: For clinical study, we selected the 40 LCPD children with definite shortening. They were 20 children at active disease and 20 children at skeletal maturity. We made teleoroentgenogram for all children. For experimental study, we made LCPD simulation in 30 piglets by disrupting the blood supply to the capital femoral epiphysis.

Results: In clinical study, total shortening in skeletal maturity group was 14.6mm, which consisted of 3.2mm(16%) shortening by decreased epiphyseal height and 11.5mm(84%) shortening by physeal growth disturbance. Total shortening in active disease group was 7.9mm, which consisted of 6.4mm(84%) decrease of epiphyseal height and 1.5mm(16%) shortening by physeal growth disturbance. In experimental study, overall shortening (13.6mm) in piglet model showed predominance of disturbed physeal growth. And its proportions are 3.2mm(24%) by epiphyseal height decrease and 10.4mm (76%) by physeal growth disturbance.

Conclusion: Physeal growth disturbance was mostly responsible for the residual shortening following LCPD. However, in stage of active disease, the shortening of the extremity was mainly caused by decrease of epiphyseal height.