The importance of the acetabular rim in the genesis of congenital hip dysplasia. Experimental research.

The posterior aspect of the cartilaginous acetabular rim was surgically removed in very young rabbits in order to study its effect on the further development of the acetabular cavity. A dysplasic change was produced which led to posterior hip dislocation. Through an analysis of the morphological, radiographic and histological findings, and comparison with human congenital hip dislocation, the acetabular rim is considered to be physiologically responsible for the development of the retaining properties of the acetabular cavity. Moreover, a genetic abnormality altering the physiological development of the cartilaginous acetabular rim, is responsible for the non-retaining power of the acetabulum which leads to congenital hip dislocation.