A study to be presented at the AAOS 2022 Annual Meeting identified patient characteristics and surgical factors that were associated with successful planned same-day discharge following total knee arthroplasty (TKA). Nithin C. Reddy, MD, FAAOS, orthopaedic surgeon in the department of orthopaedics at Kaiser Permanente in San Diego, will share the findings.

Dr. Reddy and colleagues sought to examine factors associated with outcomes of same-day TKA among a large U.S. population. “With the expansion of same-day-discharge TKA, there is a need to identify patient factors and perioperative practices that increase the risk for failure to discharge (FTD). Prior studies have been limited to small numbers of patients and care teams or large database studies lacking practice details,” they wrote.

The investigators utilized data from a national total joint registry to conduct their cohort study. Eligible patients underwent primary unilateral TKA for osteoarthritis between 2018 and 2020 and had a planned same-day discharge.

The team used a conditional logistic regression model to analyze the follow variables for associations with FTD:

• patient characteristics (age, BMI, gender, race/ethnicity, smoking status, American Society of Anesthesiologist [ASA] classification, and 27 medical comorbidities identified from the Elixhauser algorithm)
• surgical factors (operative start time, total operative time, anesthetic technique, type of spinal anesthesia [long, short, mixed, or none], and whether interpreter services were requested)
• medication utilization (multimodal [i.e., acetaminophen, benzodiazepine, clonidine, gabapentinoids, hydrocortisone, ketamine, and NSAIDs], antinausea, nerve block, opioids, and Dalury cocktail)

To address differences between surgeons and hospitals, the team created a cluster term for the operating surgeon and facility. The final multivariable model was constructed via stepwise regression according to the Akaike Information Criterion.

Overall, data from 30,072 patients were included for analysis. The rate of FTD was 25.4 percent, or 7,628 patients. The mean patient age was 67.8 years, and the cohort was mostly female (60.5 percent). Patients were treated by a total of 161 surgeons at 28 institutions.

Several patient factors and comorbidities were associated with FTD and were included in the final model (Table 1). Patient characteristics included female gender; Asian, Black, and Hispanic race/ethnicity (versus white race); ASA ≥3; and increasing age. Comorbidities associated with a higher likelihood of FTD were:

• anemia (chronic blood loss or iron deficiency)
• fluid/electrolyte disorders
• weight loss
• drug abuse
• congestive heart failure
• neurological disorders
• peripheral vascular disease
• depression
• diabetes
• renal failure
• chronic pulmonary disease

Regarding procedure-related factors, general or mixed (both general and regional) anesthesia was more strongly associated with FTD compared with regional anesthesia only. Long-acting spinal anesthesia and longer operative time were also associated with FTD.

The perioperative use of several medications was related to FTD. Pre- or postoperative use of opioids was significantly associated with failure, as was pre-, intra-, and postoperative use of benzodiazepine. Postoperative use of preventative or therapeutic antinausea agents were also related to a higher risk of FTD.

Conversely, several factors were associated with a lower likelihood of FTD, including operative time—surgeries that started before noon were less likely to fail to discharge that day. The use of interpreter services was also associated with a reduced likelihood of failure. Dalury cocktails, nerve blocks, preoperative NSAIDs, preoperative or intraoperative preventative antinausea agents, ketamine, and a history of hypertension were also all associated with lower likelihood of FTD.

In summary, Dr. Reddy and colleagues wrote, “We found several patient characteristics and comorbidities, surgical factors, and perioperative medications that may impact success of a planned same-day discharge TKA. These findings can be used to counsel patients, resource plan, and improve preoperative optimization, as well as perioperative protocols.”

The study will be presented as Paper 657 on Friday at 2 p.m. in Room S105b.

Dr. Reddy’s coauthors of “Patient and Perioperative Risk Factors for Failure to Discharge after Planned Same-day Total Knee Arthroplasty: A Multicenter Study” are Michael Vostrejs, MD; Liz Paxton, PhD; and Heather Ann Prentice, PhD, MPH.

Rebecca Araujo is the associate editor of AAOS Now. She can be reached at raraujo@aaos.org.