The Predictability of the Outpatient Arthroplasty Risk Assessment Score on Clinical Outcomes Following Revision Total Joint Arthroplasty: A Preliminary Registry Analysis.

Abstract

The Outpatient Arthroplasty Risk Assessment (OARA) Score was developed to identify surgically appropriate patients for outpatient total joint arthroplasty (TJA). In addition, it has shown excellent predictive ability for length of stay (LOS) following primary TJA compared to other medical risk stratification systems. However, it has not been studied in the revision TJA (rTJA) patient population. This study evaluated the OARA score's ability to predict LOS and postoperative outcomes following rTJA. From 2017 to 2023, 366 rTJAs (116 hips, 250 knees) performed across 17 locations were analyzed. Statistical models evaluated the predictive ability of the OARA Score on same-day or next-day discharge, complications, and readmissions within 90 days. P-values ≤ 0.05 were considered statistically significant. Overall, 156 (51%) rTJAs were discharged postoperatively on the same or the next day. A lower OARA score was a significant predictor of same- or next-day discharge, and proportionally fewer complications and readmissions (P ≤ 0.035). There were 71% of rTJAs discharged ≥ 2 days postoperatively when the OARA score was ≥ 113. Likewise, complications (19.6 versus 4.7%, P = 0.002) and readmissions (13.0 versus 3.4%, P = 0.016) were ≥ 4.2 (95% confidence interval, 1.4 to 12.8) times more likely when the OARA score was ≥ 113. For all models related to LOS, positive predictive values were great to excellent (range, 73 to 91%), while false positive rates were higher than ideal (range, 63 to 76%). The study results demonstrate that a lower OARA score was predictive of same- or next-day discharge and fewer complications and readmissions following rTJA. As the burden of rTJA rises, future studies with higher sample sizes and accounting for revision etiology and the number of components revised should be conducted to further test the OARA Score's utility in the rTJA population.