Experimental substantiation of acetabular component impaction with uncoverage in arthroplasty of patients with severe hip dysplasia

Abstract

Purpose. Estimation of critical value of acetabular component uncoverage enabling its implantation without an additional support. Methods. A comparative analysis of an original method for intraoperative measurement of uncoverage space of acetabular component based on the measurement of the depth of uncovered sector with X-ray control by the same technique was carried out. Mathematical computer modeling based on the finite element techniqueand the mechanical experiment were performed. Critical values of uncoverage enabling safe primary fixation of acetabular component were estimated in designed models. Results. High rate of coincidence of direct intraoperative and postoperative measurements by radiograms was obtained, testifying to the possibility of application of this technique of uncoverage estimation at the stage of preoperative X-ray planning in patients with different degree of dysplasia. Using the finite element technique and the mechanical experiment on pelvis models, a possibility of mounting anacetabular component with moderate uncoverage within 25% without screws and with significant uncoverage to 35% with additional two screws fixation was demonstrated.