July 16, 2018
2 min read

Higher risk for surgical complications reported with outpatient vs inpatient TKA

Researchers found an increase in outpatient TKA performed from 2007 to 2015.

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.

Patients who underwent outpatient total knee arthroplasty showed a slightly higher risk for perioperative surgical complications that was statistically significant in results of a retrospective study presented at the American Academy of Orthopaedic Surgeons Annual Meeting and published in The Journal of Bone & Joint Surgery.

“While [outpatient TKA is] effective in places that have good experience and established protocols, these small differences may reflect trends from centers that have less experience with it, places where they do not do outpatient total joint [replacement] as frequently or do not have as streamlined or well-designed follow-up processes or rehabilitation protocols. That can be reflected potentially in those small differences,” Armin Arshi, MD, resident physician in the department of orthopedic surgery at David Geffen School of Medicine, University of California, Los Angeles, told Orthopedics Today.

Armin Arshi, MD
Armin Arshi

Outpatient vs inpatient TKA

There was a small, but statistically significant difference in surgical site infections, postoperative stiffness requiring manipulation under anesthesia and component revisions at 1 year postoperatively between outpatient and inpatient TKA procedures, Arshi noted in his presentation.

Patients who underwent outpatient TKA had a slightly higher incidence of postoperative deep vein thrombosis, however results showed no differences in terms of cardiac and cerebrovascular events, acute renal failure and pulmonary events between the two groups, he said.

“One of the things you would expect is that outpatients who get TJRs are healthier on average, have more support at home, are more mobile and when we adjusted for variables such as baseline age and comorbidities and gender differences, we found that outpatients had a slightly higher risk of some of these complications,” Arshi told Orthopedics Today. “That was surprising in a sense.”

According to Arshi, that finding is somewhat understandable because it might make a difference in the risk for complications when outpatient TJR is performed at centers that are less experienced with these types of procedures.

Increase in outpatient cases

The results were based on 4,400 patients in the Humana administrative claims registry who underwent outpatient TKA with discharge in fewer than 24 hours and 129,000 control patients who underwent in-patient TKA. Findings showed the annual incidence of outpatient TKA increased during the period of the study, which was 2007 to 2015.

“The increase in incidence of outpatient TKA is not surprising given the literature that has come out showing great success in individual high-volume institutions and the gradual trend toward lowering costs to institutions. It is not surprising that surgeons and hospitals, as a whole, would make the transition to doing outpatient joint replacement as a way of saving hospital-related costs,” Arshi said.


New research should review outpatient TKA in randomized controlled trials and focus on individual institutions or practice regions to identify which practices are associated with higher complication profiles, he said. Investigators should identify particular rehabilitation protocols, discharge criteria or antibacterial regimens that may help decrease the complication rate, he said.

“These are differences where, if you are an inpatient, you may get 24 hours with an antibiotic or you may work with physical therapy in a supervised way every day. But some of those things, especially in places where it is less well-defined or less protocol-driven, can be an issue with early discharge,” Arshi said. – by Casey Tingle

Disclosure: Arshi reports no relevant financial disclosures.