Incidence, Causes, and Timing of 30-Day Readmission Following Total Knee Arthroplasty

It is important to study the incidence and causes of readmissions in order to understand why they occur and how to reduce them. This study looks at a national sample of patients following total knee arthroplasty (TKA) to identify incidences, trends, causes, and timing of 30-day readmissions.

Patients undergoing primary TKA from 2012 to 2016 in the American College of Surgeons National Surgical Quality Improvement Program database were identified (n = 197,192). Patients with fractures (n = 177), nonelective surgery (n = 2234), bilateral TKA (n = 5483), and cases with unknown readmission status (n = 1047) were excluded, leaving a total of 188,251 cases. Linear regression analysis was used to determine trends over time.

The incidence of overall 30-day readmission following primary TKA from 2012 to 2016 was 3.19% (6014/188,251), with significant decreases in readmission rates during this time ( β = −0.001, P < .001). The top 5 causes of readmission included superficial surgical site infection (SSI; 9.7%), non-SSI infection (9.5%), cardiovascular complications (CV; 9.3%), gastrointestinal complications (8.8%), and venous thromboembolisms (8.8%). The most common cause of readmission during postoperative week 1 was CV complications (12.2%), week 2 was superficial SSI (11.6%), week 3 was deep SSI (11.4%), and week 4 was deep SSI (12.4%).

Overall, 30-day readmissions following TKA were found to significantly decline from 2012 to 2016. The most common causes of overall readmission included superficial SSI, non-SSI infection, CV complications, gastrointestinal complications, and venous thromboembolisms. However, the most common causes of readmission changed from week to week postoperatively. This data may help institutions develop policies to prevent unplanned readmissions following TKA.