Congenital dislocation of the hip without acetabular dysplasia.

Congenital dislocation of the hip and acetabular dysplasia apparently are not constant features of the same disease. Cases of congenital dislocation of the hip with well-developed acetabula are reported periodically. The causative factors are genetically determined or unknown. In routine clinical work, a well-developed acetabulum improves the prognosis, even in the presence of severe dislocation. An acetabular operation is often unnecessary and the reduction is more stable. Once reduction is achieved, acetabular growth seems to continue at its usual pace in these patients.