Legg-Calvé-Perthes disease: a study of lower extremity length discrepancies and skeletal maturation.

Lower extremity length discrepancies and skeletal maturation have been studied in 147 patients with unilateral Legg-Calvé-Perthes disease followed by orthoroentgenograms for 5 or more years. At the time of initial assessment there was a marked delay in skeletal age as related to chronologic age in 83 percent of the patients. Standing height in the majority of patients both at disease presentation and at skeletal maturation was less than the mean. The average maximum total femoral and tibial discrepancy during the course of the disease was 2.14 cm. The maximum femoral discrepancy averaged 1.38 cm and the maximum tibial discrepancy averaged 0.93 cm. (The time of maximum discrepancy differed in the two major lower extremity bones). The extent of tibial discrepancy correlated well with the time of immobilization in the unilateral abduction ischial weight-bearing brace. The discrepancies did not invariably increase with time and many corrected with the repair process. Four developmental patterns of the discrepancy were detected and classified. Epiphyseal arrest was resorted to in 21 percent of the patients.