"Double Cup"Technique:A Reliable Solution for the Treatment of Paprosky Type Ⅲ Acetabular Defects

Liu Quan; Zhang Rongwei; Mei Jiawei; Zhu Wanbo; Ma Ruixiang; Zhang Xianzuo; Zhu Chen

Abstract：Objective To evaluate the early clinical outcomes of the"Double Cup"technique(titanium ring-free tantalum metal revision cup as an augmentation block)for the treatment of Paprosky Type Ⅲ acetabular defects.Methods A retrospective analysis was conducted to evaluate the early clinical outcomes of 54 revision cases treated with the"Double Cup"technique for Paprosky Type Ⅲ acetabular defects at the First Affiliated Hospital of University of Science and Technology of China.from 2017 to 2023.The cohort consisted of 27 male and 27 female patients,with ages ranging from 30 to 92 years[mean age(65.8±12.3)years].Clinical functional outcomes were assessed by recording preoperative and final follow-up Harris hip scores(HHS),Oxford hip scores(OHS),and 36-item short form survey(SF-36)functional scores.Preoperative and postoperative position of the center of rotation(COR)of the hip joint and leg length discrepancy(LLD)were evaluated radiographically.The occurrence of postoperative complications such as prosthesis loosening was also assessed during follow-up.Results All 54 patients were followed up for an average duration of(35.3±20.9)months,ranging from 8 to 80 months.Preoperatively,their HHS,OHS,and SF-36 functional scores were(35.6±10.5),(24.4±7.1),and(805.7±47.5)points,respectively.At the final follow-up,these scores improved significantly to(90.6±11.5),(44.0±4.2),and(859.4±47.4)points,respectively(P＜0.001),indicating a marked improvement in hip function and overall health status.Radiographic examinations during the final follow-up revealed substantial improvements in acetabular COR and LLD compared to preoperative values(P＜0.001),suggesting successful biomechanical reconstruction.No cases of periprosthetic infection were observed postoperatively.However,6 patients experienced prosthesis dislocation,of which only 1 patient required re-revision surgery due to recurrent dislocation during the follow-up period.Conclusion The"Double Cup"technique indeed represents a viable and reliable surgical option for the reconstruction of severe acetabular defects classified as Paprosky Type Ⅲ A and Ⅲ B.This technique has demonstrated low complication rates,high safety standards,and promising functional outcomes for patients.Therefore,it is indeed worthy of being actively promoted and considered in clinical practice for patients with these complex acetabular defects.The technique's ability to effectively restore acetabular anatomy and biomechanics contributes significantly to its success and patient satisfaction.