Mid-Term Follow-Up of Acetabular Revision Arthroplasty Using Jumbo Cups

Objective To evaluate the mid-term clinical and radiographic results of revision total hip arthroplasty (THA) using jumbo cups in Chinese patients. Methods We retrospectively studied 61 patients (63 hips; 29 men [30 hips], 32 women [33 hips]) who underwent acetabular revision with jumbo cups between January 2001 and April 2016 at our institution. The mean age at the index operation was 59.4 +/- 11.4 years. The mean body mass index of the patients was 24.9 +/- 3.8 kg/m(2). Clinical evaluation was determined using the Harris hip score preoperatively and at follow up. Major complications (including instability, sepsis, and revision of the femoral or acetabular component) were recorded. Radiographic measurements included inclination and anteversion angles of the acetabular components, and the vertical and horizontal distances of the centers of rotation (V-COR and H-COR, respectively). In the 42 patients with normal contralateral hip joints, the postoperative V-COR and H-COR were compared between right and left sides. Their improvement in leg-length discrepancy (LLD) after revision THA was also evaluated. Cup survival was evaluated using the Kaplan-Meier analysis. Clinical and radiographic outcomes were analyzed. Results Mean follow up was 5.7 years (2-16 years). At the latest follow-up, the average Harris hip score (preoperative vs postoperative values) had improved from 46 to 83 (P < 0.001). No acetabular component was radiographically defined as loosened. Four hips (6.3%) had major complications: one hip was revised because of periprosthetic infection (at 3 months); one underwent femoral open reduction and internal fixation (with implant retention) because of a periprosthetic femoral fracture (at 13 months); one operated hip developed a deep infection (at 2.5 years), which was treated with antibiotics; one hip experienced recurrent dislocation (at 4.5 years). The average cup inclination angle was 40.8 degrees +/- 6.8 degrees and the average anteversion angle was 14.9 degrees +/- 6.6 degrees. Average V-COR decreased from 29.7 +/- 10.4 mm to 22.3 +/- 7.6 mm (P < 0.001). The average postoperative H-COR was 29.5 +/- 3.7 mm compared with 30.8 +/- 6.6 mm preoperatively (P = 0.145). Among the 42 patients with normal contralateral hips, the average postoperative V-COR were 22.2 +/- 8.3 mm (operated side) and 14.0 +/- 3.7 mm (contralateral side) (P < 0.001). LLD improved from -16.8 +/- 17.1 mm to -5.6 +/- 11.8 mm (P < 0.001). When failure was defined as any reoperation involving the hip, the mean 16-year hip survival was 96.8% (95% confidence interval [CI] 87.9%-99.2%). When defined as any hip reoperation or major complication, it was 92.7% (95%CI 81.2%-97.2%). Conclusion Use of jumbo cups for revision THA resulted in excellent mid-term cup survival and helped restore the COR.