Epidemiology, demographics, and natural history of congenital hip disease in adults

This study examined the epidemiology and demographics of congenital hip dis ease in 468 (660 hips) patients who were examined between 1970 and 1996. In 356 (54%) hips, the diagnosis was secondary osteoarthritis due to congenit al hip disease, and in 272 (41%) hips, the diagnosis was idiopathic osteoar thritis. In the remaining 32 (5%) hips, the diagnosis was uncertain. Of the hips with congenital hip disease, 170 (47.7%) hips were dysplastic, 85 (23 .9%) had low dislocation, and 101 (28.4%) high dislocation. The majority of patients with congenital hip disease were women (338 [95%] hips). The natu ral history of the three types of congenital hip disease was studied in 157 patients (202 hips: 102 dysplastic, 42 low dislocation, and 58 high disloc ation) who had received no treatment before the initial examination. Averag e length of follow-up was 17 years. In dysplastic hips, the disease remaine d undiagnosed until the onset of symptoms at an average age of 34.5 years. In patients with low dislocation, pain had started at an average of 32.5 ye ars due to progressive degenerative arthritis within the false acetabulum. In patients with high dislocation, in the presence of a false acetabulum, p ain started at an average age of 31.2 years, while in its absence, pain sta rted at an average age of 46.4 years due to muscle fatigue. These findings suggest dysplasia, low dislocation, and high dislocation in adults are the results of untreated dysplasia, subluxation, and complete dislocation in in fancy, respectively.