Pathologic Anatomy of Congenital Hip Disease

Abstract

Congenital dislocation of the hip (CDH) is an enigmatic disease presenting in children of varying ages and manifesting as extremely variable deformities that may affect both the acetabulum and proximal femur. The term “dislocation” is not totally appropriate to an adequate concept of CDH. Leveuf emphasized that CDH should be divided into two distinct categories — subluxation and luxation. According to his criteria the acetabular rim is forced superiorly (everted) against the ilium in subluxation, while the rim is inverted into the true acetabulum in a luxation, or true dislocation (Fig. 1). Leveuf referred to the acetabular rim as the limbus, in both the normal hip and the two types of CDH, although prevailing use of the term “limbus” seems confined to the pathologically hypertrophied, inverted acetabular margin of the complete dislocation. As demonstrated by Ogden (1974), the fibrocartilaginous acetabular rim is grossly and histologically distinct from the hyaline cartilage of the acetabulum, and this marginal tissue is easily deformed by applied pressure, whether acute or chronic.

Departments of Surgery (Orthopaedics) and Pediatries, and the Human Growth and Development Study Unit, Yale University School of Medicine, New Haven, Connecticut 06510, USA

Supported in part by grants from the Crippled Children’s Aid Society, the Easter Seal Research Foundation, and NIH Grant 1 R01 HD10854