Primary Sjögren's syndrome is not associated with poor outcomes after total hip arthroplasty: a retrospective case-control study with a matched cohort of osteoarthritis patients.

Introduction: The number of patients with primary Sjögren's syndrome (PSS) requiring total hip arthroplasty (THA) is expected to increase, but few studies have detailed their outcomes. The purpose of this study was to evaluate a THA cohort of patients with avascular necrosis of the femoral head (ANFH) who had PSS and to compare their outcomes with those of matched patients with osteoarthritis.

Method: A case-control study using data from a single-institution arthroplasty registry was performed. Forty-two THAs in 32 patients undergoing THA with a diagnosis of PSS were identified and were matched with 84 THAs in 64 patients with osteoarthritis (1:2 ratio). Functional and health-related quality of life (QoL) evaluations were performed, and complications were recorded at the last follow-up. Logistic regression was used to determine factors associated with reaching the transfusion trigger of hemoglobin < 8 g/dL (TT8) in PSS patients.

Results: After a mean 5-year follow-up, both cohorts had similar hip function and health-related QoL outcomes. The incision complications and reaching TT8 were greater in the PSS group. No differences were observed in the rate of 90-day readmission, reoperation, or overall revision. By multivariate analysis, the influencing factors for reaching TT8 in PSS patients were lower preoperative hemoglobin (OR = 0.842, 95% CI [0.741-0.958], P < 0.05).

Conclusion: Our study demonstrated PSS patients who received THA due to ANFH could achieve clinical outcomes similar to those of non-PSS patients. Improving preoperative Hb level can reduce the risk of transfusion. Key Points • THA significantly improved hip function and health-related quality of life in PSS patients with osteonecrosis of the femoral head. • Patients with PSS were more likely to reach the transfusion trigger and higher rates of incision complications after THA. • Improving preoperative Hb level can reduce the risk of transfusion for PSS patients who underwent THA.