Total knee arthroplasty (TKA) procedures are less likely to lead to successful same-day discharge among patients who are older, female, nonwhite, with a body mass index of 35 kg/m2 or higher, living with primary hypertension, and living with other comorbidities, according to the results of a recent paper.1

The same-day discharge rate is becoming an important statistic in orthopedic surgery. “We routinely have patients go home on the same day from the hospital or ambulatory surgery center [ASC],” says James MacDonald, MD, study co-author and orthopedic surgeon at Luminis Health Orthopedics, Annapolis, MD. “In the clinic, we aim to identify the correct patients who are good candidates for that discharge plan to avoid problems at home or returns to the emergency room.”

In addition, an American Society of Anesthesiologists (ASA) Physical Status Classification System score of 3 or higher also decreased the likelihood of a same-day discharge.

“Using these seven factors, we were able to generate a model that was able to correctly identify same-day discharge patients in approximately 77% of cases,” says Justin Turcotte, PhD, MBA, study co-author and director of orthopedic and surgery research at Luminis Health.

The ASA score was an important indicator of physical health used for patient selection in this study (and elsewhere), but it is only one factor.

“Our study highlights some of the specific demographics and comorbidities that should serve as red flags when deciding which patients are candidates for same-day discharge,” Turcotte explains. “The odds ratio for each risk factor was calculated holding all other variables in the model constant to independently assess their influence on same-day discharge.”

Researchers also considered the bigger picture of TKA and same-day discharge, attempting to answer questions such as “How much physical therapy will a patient need?” or “How much help at home will a patient require?”

“The answers to these questions are essential to providing the best care for each individual patient at the lowest cost,” MacDonald explains. “Our goal is to leverage large data sets and predictive models to improve our patients’ results after hip and knee arthroplasty.”

Same-day surgery decisions should be made jointly by patients and surgeons. “The surgeon’s intuition on who is a good candidate becomes our guide,” MacDonald says. “However, as more patients opt for same-day discharge and as more joint replacements are done in ambulatory surgery centers, we need to quantify the criteria upon which we choose patients for accelerated discharge.”

This paper provides useful data for surgeons to consider when creating and adjusting criteria for same-day procedures. But it is just one snapshot of the bigger picture of what may work in a particular center.

“Track your results,” MacDonald suggests. “Locally, you may find a different set of criteria to help identify appropriate patients for same-day discharge. To improve the quality of care delivered, it is essential that we continually evaluate our data and adjust our approach to achieve optimal patient outcomes.” 


  1. Turcotte JJ, Menon N, Kelly ME, et al. Preoperative predictors of same-day discharge after total knee arthroplasty. Arthroplast Today 2021;7:182-187.