Perthes' disease in South India.

One hundred sixty-five cases of Perthes' disease were observed during a 15-year period. The mean age at onset of symptoms was 9.89 years for boys and 8.71 years for girls. The overall male:female ratio was 2.58:1, with profound regional differences. Bilateral involvement was seen in ten children, and the right hip was more frequently affected in unilateral cases (R:L, 92:63). Fixed deformities were noted in 14 children. Profound restriction of hip movement was present in seven cases, and in three there was no movement at all. Seventy percent of the cases fell into Catterall's Group 3 or 4 and 20% could not be classified into any of the groups. Sixty percent of the children presented during the initial stage of the disease. One group of these children had features resembling tuberculosis, with fixed deformities, gross restriction of movement, and osteoporosis around the acetabulum. Their symptoms resolved without antitubercular treatment and their late radiologic features were those of healed Perthes' disease. Treatment planning was problematic because of the advanced age at onset, large proportion of girls, frequency of extensive involvement of the epiphysis, and socioeconomic factors.