Total Hip Arthroplasty Patients With Systemic Sclerosis Have Worse Medical Outcomes But Clinically Similar Implant Survival Independent of Immunomodulatory Therapy.

Introduction: Systemic sclerosis (SSc) is a multisystem autoimmune disorder characterized by fibrosis and often early articular degeneration. Total hip arthroplasty (THA) is a procedure for which SSc patients may be considered. However, outcomes past hospital discharge and the association of exposure to common immunomodulatory therapy (IMT) agents on such outcomes remain unknown.

Methods: Retrospective cohort study of SSc patients who underwent THA. Patients with SSc were matched in 4:1 ratio with (-)SSc controls based on age, sex, and Elixhauser Comorbidity Index. Incidence of 90-day medical and implant-related adverse events (AEs) were assessed by multivariable logistic regression, and 5-year revision was assessed by Kaplan-Meier survival analysis and log-rank test.

Results: SSc patients undergoing THA demonstrated greater odds ratio (OR) of severe (OR 1.46) and minor AEs (OR 1.47; P < 0.001 for both). However, perioperative IMT utilization was not associated with notable modification of these odds (P > 0.05 for both). SSc patients demonstrated similar odds of 90-day implant-related AEs (P > 0.05 for all) and similar 5-year revision-free survival vs (-)SSc controls (97.3% vs. 96.6%, respectively; P = 0.200).

Discussion: Patients with SSc undergoing THA experience increased 90-day medical AEs, independent of IMT utilization. Encouragingly, SSc patients demonstrated similar 90-day implant-related AEs and 5-year revision-free survival, suggesting that the major barrier to superior outcomes may not be implant related but rather driven by medical complications.