Background:

Determination of the appropriate post-discharge disposition after total hip (THA) and knee (TKA) arthroplasty is a challenging multidisciplinary decision. Algorithms used to guide this decision have been administered both preoperatively and postoperatively. The purpose of this study was to simultaneously evaluate the predictive ability of 2 such tools—the preoperatively administered Predicting Location after Arthroplasty Nomogram (PLAN) and the postoperatively administered Activity Measure for Post-Acute Care (AM-PAC)“6-Clicks” basic mobility tools—in accurately determining discharge disposition after elective THA and TKA.

Methods:

The study included 11,672 patients who underwent THA (n= 4,923) or TKA (n= 6,749) at a single large hospital system from December 2016 through March 2020. PLAN and “6-Clicks” basic mobility scores were recorded for all patients. Regression models and receiver operator characteristic curves were constructed to evaluate the tools' prediction concordance with the actual discharge disposition (home compared with a facility).

Results:

PLAN scores had a concordance index of 0.723 for the THA cohort and 0.738 for the TKA cohort. The first “6-Clicks” mobility score (recorded within the first 48 hours postoperatively) had a concordance index of 0.813 for the THA cohort and 0.790 for the TKA cohort. When PLAN and first “6-Clicks” mobility scores were used together, a concordance index of 0.836 was observed for the THA cohort and 0.836 for the TKA cohort. When the PLAN and “6-Clicks” agreed on home discharge, higher rates of discharge to home (98.0% for THA and 97.7% for TKA) and lower readmission rates (5.1% for THA and 7.0% for TKA) were observed, compared with when the tools disagreed.

Conclusions:

PLAN and “6-Clicks” basic mobility scores were good-to-excellent predictors of discharge disposition after primary total joint arthroplasty, suggesting that both preoperative and postoperative variables influence discharge disposition. We recommend that preoperative variables be collected and used to generate a tentative plan for discharge, and the final decision on discharge disposition be augmented by early postoperative evaluation.

Clinical Relevance:

The determination of post-discharge needs after THA and TKA remains a complex clinical decision. This study shows how simultaneously exploring the predictive ability of preoperative and postoperative assessment tools on discharge disposition after total joint arthroplasty may be a useful aid in a value-driven health-care model.