Application of Intraoperative Individualized Cup Combination—Cup‐on‐Cup Technique in Severe Acetabular Defects

Abstract

This study aimed to investigate the application of the cup‐on‐cup technique in revision total hip arthroplasty (THA) and report clinical and radiographic outcomes from a series of case follow‐ups. Retrospective analysis of 10 patients who underwent acetabular prosthesis revision with cup‐on‐cup technique. According to the Paprosky classification of acetabular bone defects, there were 2 cases of type II C, 3 cases of type III A, and 5 cases of type III B. The average follow‐up was 54.8 ± 5.1 months, and the Harris score of the hip joint increased from 37.0 ± 9.9 preoperatively to 80.5 ± 3.1 postoperatively at the final follow‐up (p < 0.001). Comparing the surgical side's hip center of rotation (COR) to the contralateral side, the preoperative average upward displacement was 33.8 ± 15.0 mm, while the postoperative average upward displacement was 0.2 ± 3.3 mm (p < 0.001). Similarly, the preoperative average inward displacement was 9.1 ± 5.1 mm, while the postoperative average outward displacement was 1.8 ± 1.6 mm (p < 0.001). There was no significant difference (p = 0.71) between the average density values of the contralateral and surgical sides at the final follow‐up, which were 127.4 ± 13.7 and 125.0 ± 14.8, respectively. During the follow‐up period, all patients achieved satisfactory radiographic outcomes, and no prosthetic loosening was observed. The cup‐on‐cup technique can reconstruct acetabular bone defects and restore hip COR in revision THA, with favorable clinical and radiographic outcomes.

Keywords

• acetabular bone defect
• cup‐on‐cup technique
• revision total hip arthroplasty