Effects of 3D-printed porous metal cup with hip dual-mobility revision system for reconstruction of severe acetabular ring defects in revision total hip arthroplasty / 中华骨科杂志

ABSTRACT

Objective:To prospectively analyze the early clinical effects of 3D-printed porous metal cup with hip dual-mobility revision (HDR) system in treating severe acetabular bone defects.Methods:A total of 17 patients with severe acetabular defects (15 patients in Allan-Gross type 4 and 2 patients in type 5; 2 patients in Paprosky type 2B, 4 patients in type 3A and 11 patients in type 3B) who underwent revision hip arthroplasty between July 2019 and May 2020 were analyzed. There were 7 males and 10 females (mean age 67.3±9.3 years; range 42-80 years). The average body mass index was 22.2±3.8 kg/m 2 (range 17.7-33.3 kg/m 2). The preoperative mean leg length discrepancy (LLD) was 42.9±31.1 mm (range 10-160 mm) . One patient presented positive Trendelenburg sign. The follow-up duration was 12.1±3.0 months (range 6-16 months). The clinical and radiographic hip scores in all patients were evaluated. Results:The mean Harris Hip Score (HHS) was 31.2±11.3 points at preoperatively, 63.5±10.0, 68.7±10.4 and 70.2±10.1 points at 3 days, 7 days and 1 month postoperatively. At the latest follow-up, HHS was increased to 81.6±7.0 points. The outer cup mean abduction angle was 48.1°±10.6° and the mean inclination angle was 10.8°±6.0° postoperatively. The inner cup mean abduction angle was 45.0°±6.2° and the mean inclination angle was 10.8°±3.7°. The mean LLD decreased to 11.1±3.8 mm (range 0-15 mm) after surgery. At the latest follow-up, all acetabular components were radiologically stable without displacement. No osteolysis or absorption was observed. There was no infection, loosening or nerve injury in all cases.Conclusion:During short-term follow-up, the 3D-printed porous metal HDR system can effectively enhance the stability of implants with satisfied quality of life. It can provide a good result for the revision of total hip arthroplasty with severe acetabular defects.