Revision Total Hip Arthroplasty with Primary Stem or Full-Porous-Coated Long Stem for Aseptic Femoral Component Loosening: A Matched-Pair Study

Meng-Huan Tsai,1 Chun-Chieh Chen,1– 3 Chih-Hsiang Chang,1– 3 Yuhan Chang,1– 3 Pang-Hsin Hsieh,1– 3 Chih-Chien Hu1– 3 1Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Taoyuan, 33305, Taiwan; 2Bone and Joint Research Center, Chang Gung Memorial Hospital, Taoyuan, 33305, Taiwan; 3College of Medicine, Chang Gung University, Taoyuan, 33305, TaiwanCorrespondence: Chih-Chien Hu, Bone and Joint Research Center, Chang Gung Memorial Hospital, Kweishan, Taoyuan, 33305, Taiwan, Tel +886-3-3281200, ext. 2420, Email chihchienhu@hotmail.comBackground: Revision total hip arthroplasty (RTHA) for loosening the femoral stem is a technical challenge. Distally fixed, full-porous-coated long stems are widely accepted as the standard selection for these revisions. However, the success of primary stems in RTHA is not well known.Methods: This study enrolled 24 patients with aseptic loosening of the femoral stem who underwent RTHA using primary stems. Another 72 patients with aseptic loosening who underwent RTHA using full-porous-coated long stems were matched in terms of operation date, proximal femoral bone stock (Paprosky classification), sex, and age. The primary and secondary outcomes of failure were the need for revision for any reason and the radiographic change in the stem respectively.Results: In the primary stem group, one patient had a periprosthetic fracture and received a second RTHA 2 years after the previous one. The primary outcome’s 5-and 10-year survival rates were both 95.8%. For the matched comparison group, one patient had an immediate periprosthetic fracture of the femoral shaft requiring further open reduction internal fixation surgery. Another patient had a full-porous-coated long stem breakage 6 years postoperatively, which required a second RTHA. The primary outcome’s 5-and 10-year survival rates were 98.6% and 97.2%, respectively.Conclusion: Primary stems can achieve non-inferior clinical success compared to a full-porous-coated long stem for aseptic stem loosening RTHA in patients with adequate proximal femoral bone stock.Keywords: revision total hip arthroplasty, aseptic loosening, primary stem, full-porous-coated long stem