Early clinical effects of severe acetabular bone defects with 3D technology assisted tantalum augment

Abstract

Objective To investigate the early clinical effects of tantalum augment assisted with 3D technology in treating acetabular bone defects of Paprosky type III in revision total hip arthroplasty (THA). Methods From May 2013 to July 2017, a total of 16 patients (18 hips) undergoing revision THA were retrospectively analyzed, including 11 males and 5 females aged 58.06±8.29 years (range 44-69 years). There were 3 cases with infective loosening and 15 cases with aseptic loosening, 13 cases with Paprosky IIIA type bone defects and 5 cases with IIIB type bone defects. 3D technology was used for precise planning before operation. The tantalum augment and cup were used to repair acetabular bone defects during operation. Cup anteversion, abduction angle, ratio of the lateral and contralateral vertical distance of the center of rotation, ratio of the lateral and contralateral horizontal distance of the center of rotation and femoral offset were measured preoperatively and postoperatively. The percentages of hips located in Lewinnek safe zone were calculated preoperatively and postoperatively. Postoperative radiographic evidence of loosening and Harris score were collected at the end of the follow-up. Results The percentage of the hips located in Lewinnek safe zone increased from 22% (4/18) preoperatively to 61% (11/18) postoperatively. The mean anteversion of the operative side was 11.99°±6.91° (range 1.71°-26.36°) postoperatively. The mean abduction angle of the operative side was 44.91°±5.93° (range 35.6°-56.0°). The mean ratio of the lateral and contralateral vertical distance of the center of rotation was 1.10±0.20 (range 0.87-1.62). The mean ratio of the lateral and contralateral horizontal distance of the center of rotation was 1.00±0.18 (range 0.69-1.46) and the mean ratio of the lateral and contralateral femoral offset was 1.01±0.66 (range 0.51-3.56). All the patients were followed-up for an average of 27.72±12.18 months (range 14-53 months). No complications, such as periprosthetic joint infection, dislocation or aseptic loosening, were observed in all patients. The mean Harris score was 77.28±4.80 (range 65-85) at 6 months postoperatively and 80.9±5.2 (range 69-89) at the end of the follow-up. Conclusion Using tantalum augmentassisted with 3D technology to re construct Paprosky type III severe bone defects of the hip can increase the accuracy of the acetabular cup positioning. The short-term outcomes are satisfying and no early prosthetic loosening was observed. Key words: Arthroplasty, replacement, hip; Reoperation; Tantalum; Imaging, three-dimensional