Peculiarities of acetabulum morphology determining the technology of pelvic prosthesis component implantation

Abstract

Introduction. The most effective method of treatment of patients with severe forms of coxarthrosis is endoprosthetics, the success of which directly depends on the correctness of preoperative planning based on knowledge of the morphology of the acetabulum in normal and pathological conditions. The aim of the investigation was to reveal the morphological features of the acetabulum in osteoarthritis of the hip joint, determining the technology of implant bed preparation for the prosthesis cup. Materials and methods. The study was conducted on 19 macerated pelvic preparations and 72 direct projection pelvic radiographs in 72 patients with stage III osteoarthritis of different etiology aged from 41 to 70 years (61.5 ± 1.4). Hyperplastic coxarthrosis was observed in 21 (29.2%), protrusion in 23 (31.9%), and dysplastic in 28 (38.9%) cases. Clinical, radiological, morphometric, and statistical methods of investigation were used. Methods of descriptive statistics were used. Results. The following data were obtained during morphometric studies: In hyperplastic coxarthrosis, the bottom thickness was 11.9±1.83 mm with an acetabular index (IVI) of 0.51±0.019; in protrusion coxarthrosis, the bottom thickness was significantly reduced and was 5.7 ± 0.93 mm, IVI of 0.66 ± 0.039; in dysplastic coxarthrosis, the bottom thickness was 14.5 ± 1.18 mm, IVI 0.42 ± 0.024 respectively. Discussion. Studies on acetabulum morphometry are being conducted worldwide; among residents of different countries, data on the depth of the acetabulum differ, the morphometric data obtained by us are relevant in terms of the variational anatomy of the population of the Ural region. The morphological features of acetabulum affect the technology of preparing the implant bed for the prosthesis cup, so the preoperative design of implantation is relevant. The proposed method of finding the center of rotation of the deformed acetabulum makes it possible to determine the required thickness of augments to compensate for bone defects in the area of the acetabulum floor and arch. Conclusions. The morphological features of the acetabulum in hyperplastic, dysplastic, and protrusion coxarthrosis determine the technology of implant bed preparation for a prosthetic cup.