Study on relationship between Crowe type and 3D CT reconstruction evaluation for adults with developmental dysplasia of the hip / 中华骨科杂志

ABSTRACT

Objective To analyze the evolution of acetabular morphology changes of different Crowe types among adults with developmental dysplasia of the hip through standard hip 3D CT reconstruction.Methods From June 2010 to January 2013,there were 62 patients with 68 hips (8 hips of 6 male cases,56 female cases of 60 hips) diagnosed as acetabular dysplasia in our hospital,with an average age of 53.7±5.8 years old (range,47-59 years).According to Crowe classification,there were 14 cases (17 hips) of Crowe type Ⅰ,17 cases (17 hips) of Crowe type Ⅱ,15 cases (17 hips) of Crowe type Ⅲ,and 16 cases (17 hips) of Crowe type Ⅳ.Through standard hip 3D CT reconstruction,Harris nest in the pelvic side 3D image was marked,and the coronal and horizontal position of acetabular rotation center was determined by using the cross axis; secondly,in the anteroposterior 3D image (by gray level adjustment to the shape of X ray perspective effect) through Ranwant triangulation,sagittal position of the center of rotation of the hip joint was determined; finally,the acetabular rotation center in the acetabular horizontal reconstruction plane.The bone stock of anterior and posterior columns of acetabular was observed and acetabular anteversion,front cover angle,rear cover angle and medial wall thickness were measured.Results 1) With Crowe type increased,acetabular anteversion angle gradually increased as well,and there was a positive correlation between them with statistically significant (P＜0.05) except in Crowe Ⅰ and Ⅱ group.2) With Crowe type increased,anterior acetabular coverage angle was significantly decreased; the mean anterior acetabular coverage angle of Crowe Ⅲ and Ⅳ groups was less than 50°.3) With Crowe type increased,posterior acetabular coverage angle was decreased significantly as well the mean posterior acetabular coverage angle of Crowe Ⅲ and Ⅳ groups was less than 90°.4) With Crowe type increased,acetabular medial wall thickness was increased significantly.Conclusion Adult acetabular morphology changes between different Crowe types in patients with developmental dysplasia of the hip.For acetabular reconstruction of Crowe Ⅰ and Ⅱ,we could make full use of the acetabular bone stock of anterior and posterior column; for acetabular reconstruction of Crowe Ⅲ and Ⅳ,we could moderately shift the acetabular center superiorly and (or) medially.