Hip Arthroplasty in Patients with Hip Dysplasia by Individual Augments: Early Results

Abstract

Relevance. The altered hip anatomy makes total hip arthroplasty in patients with hip dysplasia a difficult and non-standard task. The acetabulum is deformed with femoral head in subluxation or dislocation. The most important task of surgery is to restore the anatomical position of the hip center of rotation.The study purpose — to evaluate the early results of hip arthroplasty with individual augments in the patients with hip dysplasia.Materials and Methods. Since 2017, nine patients with hip dysplasia have undergone surgery using individually printed augments. All patients were women with average age 51.3±14.5 years (23 to 67). The mean follow-up was 14.3±5.2 months (8 to 20). Patients were evaluated using follow-up X-rays, a visual analogue scale (VAS), Harris Hip Score (HHS), and Western Ontario and McMaster Universities Arthritis Index (WOMAC).Results. There was no a single case of endoprosthesis dislocation, loosening of components, prosthetic infection or revision surgery in the analyzed group of patients. The planned sizes of the acetabular components were equal to the placed in 7 cases (77.8%). In two cases (22.2%), the acetabular components were 2 mm larger because the surgeon wanted a greater degree of press-fit fixation. The restoration of the anatomical position of the acetabular component was noted. Before the surgery, the femoral head was on average 22.7±11.7 mm (10 to 43 mm) higher. After the surgery, the level of the acetabular component was on average only 0.75±2.1 mm (1.7 to 5 mm), p = 0.008. Also, there were a decrease in pain and quality of life improvement by VAS from 6.78±1.39 before surgery to 2.22±1.09 at follow-up (p = 0.007), HHS increase from 30.5±18. 1 to 77.59±14.26 (p = 0.008), and WOMAC decrease from 73.3±14.1 to 18.22±8.2 (p = 0.008).Conclusion. The individually printed augments have shown high efficacy for restoration of the anatomical center of rotation and good early results in the patients with hip dysplasia undergone hip arthroplasty.