Methods of acetabular defect visualization in dysplastic hip arthritis

• Main Authors: O.Ye. Oleynik, T.O. Zub
• Format: Article
• Language: English
• Published: Zaslavsky O.Yu. 2019-08-01
• Series: Bolʹ, Sustavy, Pozvonočnik
• Subjects: dysplastic hip arthritis; acetabulum; plane roentgen-anthropometry; hip arthroplasty
• Online Access: http://pjs.zaslavsky.com.ua/article/view/178645

Background. There is an opinion that according to the displacement of the femoral head, hip arthritis may be divided into central and superolateral forms; the latter is usually caused by the dysplastic changes of the hip joint. The extant classifications of the developmental dysplasia of the hip mostly describe either an acetabular contour or the cranial distance at which the femoral head becomes displaced. However, none of them takes into account dysplastic defects of the acetabulum or their influence on the results of the surgery. The purpose of the study was to evaluate the roentgen-anthropometric parameters of the dysplastic acetabulum and visualize the defects, affecting the outcomes of the total hip arthroplasty. Materials and methods. The roentgen-anthropometric analysis of 201 dysplastic hips and 70 normal hips acetabula was performed. We’ve studied the acetabular width, depth, thickness of the acetabular bottom, acetabular index and inclination and vo­lume of the acetabular dysplastic defect. Statistical analysis included mean, relative values, median, quartiles, nonparametric Mann-Whitney and Kruskal-Wallis criterion with median-test, nonparametric Kendall correlation. The difference between values was considered significant if p < 0.05. Results. On performing statistical analysis, we found out that in types A-C by Eftekhar classification, the acetabular parameters were changing linearly. Some of them were combined in pairs. For example, the acetabular width increase was accompanied by an inclination increase; however, inclination increased more significantly. The bottom thickness and acetabular depth had an inverse correlation. The diagram for visualization of the changing parameters was drawn, and a pairing table was built. The latter allows creating a formula for any dysplastic acetabulum. A concept of the dysplastic defect was considered separately. Its prevalence rate and linear sizes represent the difference between the location of the rotation center of the femoral head in case of dysplastic hip arthritis and rotation center of the normal hip joint. Conclusions. Deformations of the acetabulum in the developmental dysplasia of the hip reflect the difficulties the surgeon faces during the preoperative planning and implantation. However, understanding of the pathomorphology of this process helps to solve some problems associated with implantation technique, e.g. bottom resection or required bone grafting of the dysplastic defect, and need for an additional preoperative examination in the patients.