The early effects of revision hip arthroplasty for reconstruction of Paprosky type III acetabular defect using Cup-in-Cup technology / 中华骨科杂志

ABSTRACT

Objective:To investigate the early effects of cup in cup technique in reconstructing paprosky III acetabular bone defect in revision hip arthroplasty.Methods:From January 2017 to December 2019, a total of 20 cases (20 hips) with paprosky III acetabular bone defect were reconstructed by Cup-in-Cup technique, including 9 males and 11 females. The age ranged from 45 to 76 years, with an average of 64.6 years. The causes of revision were aseptic loosening of prosthesis in 17 cases and loosening of prosthesis caused by periprosthetic infection in 3 cases. There were 13 hips with acetabular bone defect of paprosky IIIA and 7 hips with paprosky IIIB. The acetabular side was repaired in 13 cases, and the acetabulum and femoral side were repaired in 7 cases at the same time. Harris hip score was used to evaluate hip function during postoperative follow-up. The occurrence of serious complications such as intraoperative vascular and nerve injury, postoperative prosthesis dislocation, periprosthetic infection and fracture were counted. The height and horizontal position of hip rotation center were measured by X-ray film.Results:The operation duration was 110±25 min (range 80-180 min) and intraoperative bleeding was 700±180 ml. All cases were followed up for 12-36 months, with an average of 18 months. At the last follow-up, the Harris hip score of 16 cases was more than 80, with excellen in 2 cases, good in 14 cases and fair in 4 cases. The Harris score was 84.3±7.5, which was significantly higher than that before operation 40.1±16.6 ( t=15.34, P<0.001). The height of hip joint rotation center on the affected side decreased from 34.2± 3.3 mm before operation to 18.6±2.8 mm after operation with significant difference ( t=15.11, P<0.001). The horizontal distance increased from 18.1±5.5 mm before operation to 26.2±7.3 mm after operation with significant difference ( t=-5.95, P<0.001). After operation, the height of hip joint rotation center on the affected side was slightly higher than that on the opposite side, with a significant difference between the affected side 18.6±2.8 mm and the opposite side 12.2±3.3 mm ( t=6.73, P=0.018). The horizontal position was 26.2±7.3 mm, which had no significant difference compared with the contralateral 30.1±5.5 mm ( t=-3.29, P=0.381). There was no vascular and nerve injury, periprosthetic infection or incision related complications. During the following-up, the prosthesis was in satisfied position without prosthesis or screw loosening and fracture. Conclusion:The reconstruction of paprosky III acetabular bone defect with Cup-in-Cup technique in revision hip arthroplasty can obtain satisfied early effects, with achieving relatively normal hip rotation center and initial stability.