The Correlations of the Radiological Parameters of Hip Dysplasia and Proximal Femoral Deformity in Clinically Normal Hips of a Korean Population

BACKGROUND: The aim of this study was to answer the following two questions: 1) Do the radiological parameters of dysplasia have significant correlations between themselves or with the parameters of the proximal femoral deformity and vice versa? 2) Do the physical parameters have a significant correlation with the radiological parameters of hip dysplasia and proximal femoral deformity? METHODS: Four hundred and twenty eight consecutive patients with no clinical evidence of hip osteoarthritis and who underwent pelvic radiography in the supine position for hip contusion or a routine health check were analyzed for the relationships between the center-edge (CE) angle, acetabular depth, acetabular angle, the head-neck ratio and the neck-shaft angle as well as the relationships of the above-mentioned variables with age, gender, body height and the body mass index. RESULTS: The CE angle, acetabular depth and acetabular angle showed a strong correlation with each other. The neck-shaft angle and the head-neck ratio showed no correlation with each other or with the CE angle, acetabular depth and acetabular angle. Age was positively associated with the CE angle, and inversely associated with the acetabular depth or acetabular angle. Male gender was significantly associated with the increased neck-shaft angle, and inversely associated with the head-neck ratio. CONCLUSIONS: The radiological parameters of hip dysplasia are all strongly, if not perfectly, inter-correlated. Age was associated with the radiological parameters of hip dysplasia whereas gender was associated with the radiological parameters of a proximal femoral deformity.