Introduction: The incidence of Legg-Calvé-Perthes Disease (LCPD) has varied considerably both between countries and between population groups. The incidence of LCPD has not been reported in Korea. The purpose of this study was to determine the annual incidence of LCPD in Korea and to compare this to other population groups.

Materials and Methods: Firstly, only LCPD children who were living in Chonnam Province, Korea, and were aged 14 years and under during the years 1999, 2000, and 2001, were reviewed to measure the annual incidence. Secondly, for a further study regarding the variables related to the epidemiological interest, 816 hips, which were treated at our hospital during the last 32 years from 1972 to 2003, were reviewed.

Results: The population aged 14 years and under was 734,645 in 1999, 728,721 in 2000, and 719,504 in 2001. Among them, the number of LCPD children was 29 in 1999, 28 in 2000, and 24 in 2001. The annual incidence was 3.9 per 100, 000 in 1999, 3.8 in 2000, and 3.3 in 2001, with a mean incidence of 3.7 per 100, 000.

Discussion: The annual incidence of LCPD in Korean children aged 14 years and under was 3.7 per 100,000. This Korean incidence was lower than the 5.1 to 21.1 per 100,000 incidence reported in Caucasians and higher than the 0.45/100,000 reported in blacks or mixed decent. The incidence of gender, bilaterally, age of disease onset, extent of head involvement, and other related epidemiological parameters was similar to those reported in other studies.

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 this residual shortening after LCPD. There has been no clear answer regarding which is more responsible for the residual shortening between coxa plana and the disturbed physeal growth. To clarify the main cause of residual shortening, clinical and experimental studies were conducted.

Materials and Methods: For clinical study, 40 LCPD children with definite shortening were evaluated. This included 20 children with active disease and 20 children at skeletal maturity. Teleoroentgenograms were obtained for all children. For the experimental study, LCPD simulation in 30 piglets was achieved by disrupting the blood supply to the capital femoral epiphysis.

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

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

Introduction: Osteonecrosis of the femoral head remains a challenging problem especially in young patients. The purpose of this study was to evaluate the clinical results of a viable iliac bone graft for treating osteonecrosis of the femoral head.

Materials and Methods: Seventy-one hips in 52 patients underwent a viable iliac bone graft (9 hips-vessel pedicle iliac bone graft and 62 hips-muscle pedicle iliac bone graft). The clinical and radiographic results were evaluated after an average of 3 years and 4 months (range, 2 to 5 years). Patient age ranged from 20 to 40 years with an average of 31 years. Twenty-three hips were classified as Ficat stage 2 disease and 48 as stage 3 disease. The causes of osteonecrosis were excessive alcohol consumption in 30, steroid use in 13, posttraumatic in 4, decompression sickness in 1, and unknown in 23 hips. The clinical results were evaluated based on the patients’ satisfaction and pain score. The radiographical results were evaluated by serial follow-up roentgenography and pinhole bone scintigraphy.

Results: The clinical and radiological results were satisfactory. Overall, the survival rate was 96 percent. Excellent results were obtained in 15 hips, good in 39, fair in 6 and poor in 8. Three hips underwent total hip replacement, including one infected case. Excellent or good results were obtained in 82 percent of stage 2 cases and in 65 percent of stage 3 cases. The serial roentgenographic examination revealed a gradual incorporation of the grafted bone, and the scintigraphic examination revealed a gradual increase in the uptake which suggested an increased blood supply to the femoral head.

Discussion: The overall results of viable iliac crest bone grafting were very satisfactory. This technique is recommended particularly for young patients with stage 2 or 3 osteonecrosis of the femoral head. Pinhole bone scintigraphy was quite useful for evaluating the healing process after the revascularization procedure.