Enhanced Selection of Candidates for Same-Day and Outpatient Total Knee Arthroplasty

BACKGROUND

Medicare removed total knee arthroplasty (TKA) from its inpatient-only list and private insurers created ambulatory surgical codes; these changes bring about logistical challenges for TKA episode planning. We identified preoperatively determined factors associated with hospital length of stay for (1) same-day discharge (SDD) and (2) inpatient TKA defined by Medicare's 2-midnight rule benchmark.

METHODS

We retrospectively reviewed 325 consecutive unilateral primary TKAs performed on patients completing the Perioperative Surgical Home preoperative optimization pathway within a single hospital system. Stepwise logistic regression modeling was performed to identify preoperatively determined factors associated with (1) SDD and (2) inpatient TKA. We compared these models' ability to discern the length of stay category to the Risk Assessment and Prediction Tool (RAPT) score alone.

RESULTS

The cohort included 32 (10%) SDD, 189 (58%) next-day discharges, and 104 (32%) inpatients. Lower body mass index (BMI; odds ratio [OR], 0.92; 95% CI, 0.85-0.1.0; P = .04) and fewer self-reported allergies (OR, 0.66; 95% CI, 0.46-0.95; P = .03) were associated with SDD. The SDD model outperformed the RAPT alone (C-statistic, 0.73 vs 0.52; P < .01). Older age (OR, 0.96; P = .04), higher BMI (OR, 0.93; P 0.01), lower RAPT score (OR, 1.2; P = .04), and later surgery start time (OR, 0.80; P < .01) were associated with inpatient discharge. The inpatient model outperformed the RAPT alone (C-statistic, 0.74 vs 0.62; P < .01).

CONCLUSION

We identified preoperatively determined factors associated with (1) SDD as BMI and allergies and (2) inpatient TKA as age, BMI, RAPT score, and surgery start time. Hospitals, providers, patients, families, and payers can use this information for TKA episode planning.

The Risk Assessment and Prediction Tool (RAPT) after Hip and Knee Replacement: A Systematic Review

Purpose  The Risk Assessment and Prediction Tool (RAPT) is an interesting instrument for predicting the discharge destination and length of stay (LOS) for patients after hip or knee arthroplasty. The aim of this review is to describe its predictive ability, current utilization, and future prospects through the analysis of scientific literature.

Methods  The databases of PubMed, Web of Sciences, Cochrane Library, and Pedro were searched for English studies on RAPT prediction capacity. Only original prospective or retrospective articles that analyze specifically the use of RAPT were included, whereas those concerned with other preoperative prediction tools or those only considering other aspects of recovery after joint replacements were excluded.

Results  A total of 27 references were retrieved, and 8 studies were selected. All analyzed studies demonstrated that RAPT could reduce LOS and accurately predict discharge disposition especially for high- and low-risk patients. In the intermediate risk category, a targeted intensive postoperative rehabilitation program has demonstrated good results in reducing the uncertain outcome.

Conclusion  Although contrarily to many of the other scores, the RAPT has been validated in multiple countries with relatively similar results between different institutions; however, its validity has yet to be tested and adapted in every nation context. Further studies confirming the predictive accuracy of RAPT at other institutions are needed as well as studies assessing the effect of using RAPT to identify patients for targeted interventions in terms of LOS, discharge disposition, clinical outcomes, and financial impact.

Level of Evidence  This is a level IV, systematic review of level III and IV study.