Outcome Disparities in Total Knee and Total Hip Arthroplasty among Native American Populations.

Background: No prior racial disparities studies in total knee arthroplasty (TKA) and total hip arthroplasty (THA) have specifically evaluated outcomes among American Indian or Alaska Native (AIAN) patients. We hypothesized that AIAN patients have worse outcomes than White patients after controlling for demographics and comorbidities.

Methods: This was a retrospective cohort study comparing White and AIAN patients undergoing primary TKA/THA from 2012-2019 using the American College of Surgeons National Surgical Quality Improvement Program. Race, demographics, and comorbidities were analyzed for correlations with 30-day outcomes and complications using multivariable logistic and linear regression analyses.

Results: Comparing 422,215 White and 2,676 AIAN patients, AIAN patients had higher American Society of Anesthesiologist (ASA) classifications, body mass index (BMI), and were younger at the time of surgery. AIAN patients more often stayed inpatient > 2 days (49.4% vs 36.2%, p < 0.001), underwent reoperation (2.1% vs 1.4%, p < 0.01), and were discharged home (91.4% vs 81.7%, p < 0.01). Regression analyses controlling for age, BMI, sex, ASA classification, and functional status found that AIAN race was significantly positively correlated with a length of stay > 2 days (OR 1.6), reoperation (OR 1.4), and discharging home (OR 2.0).

Conclusion: AIAN patients undergoing TKA/THA present with a greater comorbidity burden compared to White patients and experience multiple worse outcome metrics including increased hospital length of stay and reoperation rates. Interestingly, AIAN patients were more likely to discharge home, representing a unique racial disparity which warrants further study.