Radiographic Parameters of Acetabular Dysplasia in a Healthy Japanese Population ―Data from the Katashina Study ―

Abstract

Background & Aims:Normal values for Sharp’s angle (SA) and the center-edge angle (CEA) in Japanese are unestablished. We examined these radiographic parameters to identify their correlation with gender, age and spino-pelvic alignment and particularly the prevalence of acetabular dysplasia in healthy adults (middle-aged or older) in Japan. M ethods:In 639 members of the general population in a mountain village in Japan,the SA and CEA were measured. Correlations with gender, age and the sacro-femoral-pubic angle(SFPA)were investigated. Results:A total of 562 subjects(mean age 65.7 years;range,40-90 years)met the study criteria. The mean SA and CEA on both sides in women were larger and smaller than in men,respectively. An association was found between the SA and age in both genders. Acetabular dysplasia,based on the SA and/or CEA,was more prevalent in women than in men and on the right side than on the left. The SFPA was associated with age and the SA in both genders but almost never with CEA. Conclusions:There were gender-associated and right-left differences in the prevalence of acetabular dysplasia. The degree of pelvic retroversion was associated with age but almost never with the CEA.