Excellent 10-Year Implant Survivorship Following Primary Total Hip Arthroplasty in Patients Who Have Down Syndrome: A Retrospective Cohort Study.

BACKGROUND: Patients who have Down syndrome (trisomy 21) have unique musculoskeletal and medical characteristics that may influence outcomes after total hip arthroplasty (THA). While early postoperative complications have been described, 10-year implant survivorship in this population remains poorly defined. This study's objective was to evaluate 10-year implant survivorship and mechanical outcomes following primary THA in patients who have Down syndrome and to compare these outcomes to matched patients who did not have Down syndrome. METHODS: A retrospective cohort study was conducted using a large national database to identify patients who had Down syndrome and underwent a primary THA. Longitudinal outcomes were assessed at predefined intervals up to 10 years postoperatively. Kaplan-Meier analyses were used to estimate survivorship free from revision THA, mechanical failure, and any subsequent hip or pelvic surgery. A 1:1 propensity score-matched cohort of patients who did not have Down syndrome undergoing THA was generated to compare 10-year mechanical outcomes. A total of 255 patients who had Down syndrome were included (mean age 43 years (range, nine to 86)). RESULTS: By 10 years, revision THA occurred in 4.7% of patients. Kaplan-Meier analysis demonstrated 10-year revision-free survival of 94.6%, mechanical failure-free survival of 85.9%, and freedom from any subsequent hip or pelvic surgery of 72.6%. In the propensity-matched analysis (n = 246 per group), there were no statistically significant differences between patients who had and did not have Down syndrome in rates of revision THA (relative risk (RR) 0.92, P = 0.84), mechanical failure (RR 1.30, P = 0.24), or subsequent hip or pelvic surgery (RR 1.16, P = 0.42). CONCLUSION: Patients who have Down syndrome undergoing primary THA demonstrate excellent implant survivorship at 10 years comparable to matched controls. Trisomy 21 alone does not appear to compromise 10-year implant durability, supporting THA as a durable treatment option in appropriately selected patients.