Total knee arthroplasty (TKA) is one of the most successful procedures performed to relieve pain caused by osteoarthritis (OA). As the number of patients with OA of the knee grows, it is projected that the demand for TKA will increase to an estimated 935,000 procedures annually by 2030. 
The safety of any surgery can be a concern as patients age. Past studies have suggested that distinct complications can arise for TKA patients over age 80, including a higher risk of mortality, increased risk of medical complications, and higher rates of implant-related complications. As a result, orthopaedic surgeons and their older patients tend to be cautious in determining whether the procedure should be undertaken.
One of the issues, however, is that data comparing outcomes of octogenarians with those of non-octogenarians are limited, as many studies group older adults into a single cohort of 65 years and older. This makes it difficult to tease out conclusions about TKA in patients at different stages of their lives and then provide individualized care.
Creating 2 Distinct Cohorts
A study presented at the 2022 Annual Meeting of the American Academy of Orthopaedic Surgeons takes a step toward better defining outcomes of TKA in different groups of older adults.
Using the PearlDiver database and International Classification of Disease, 9th revisions (ICD-9) codes, they identified patients who underwent primary TKA between January 1, 2005, and March 31, 2014. They then divided these patients into 2 cohorts, matched on a 1:5 basis:
- The octogenarian study group included patients aged 80 and older (n=295,908).
- The control group included patients aged 65 to 79 (n=1,479,552).
“Literature looks at the older adults as one giant population,” said lead author Priscilla P. Varghese, MBA, MS, who is an MD candidate at The State University of New York (SUNY) Downstate College of Medicine in Brooklyn.
“By stratifying patients into these 2 cohorts, we are better able to explore the differences and reinforce a personalized approach for patients undergoing TKA. [Patients] who are 65 years old are navigating very different issues than someone who is 85 or 90 years old. We can take away specific nuances to promote quality of life.”
Primary endpoints of the study were 90-day medical complications, 90-day readmission rates, in-hospital length of stay (LOS), and 2-year implant-related complications following TKA.
The researchers found that compared with the control group, octogenarians had:
- Lower rates of implant-related complications: 1.67% vs. 1.93%
- Equal incidence of developing any medical complications: 1.26% vs 1.26%
- Higher rates of certain medical complications, including cerebrovascular accidents (0.04% vs 0.02%), pneumonia (0.07% vs 0.05%), and acute kidney failure (0.12% vs 0.10%)
- Significantly higher 90-day readmission rate: 10.59% vs 9.35%
- Significantly longer LOS: 3.69 days vs 3.23 days
“Generally, you expect older patients to have greater medical complications following TKA, so the 90-day medical complications outcomes were very interesting,” said senior author Martin William Roche, MD, who is Director of Arthroplasty at HSS Florida in West Palm Beach.
“These data will be helpful as surgeons advise patients on the decision of whether to undergo TKA. For older patients, it can be reassuring to know they can have similar outcomes to a 65-year-old and improve their quality of life. The outcomes reflect the advancements in healthcare and post-surgical interventions to alleviate complications.”
The results demonstrate the benefits of further stratifying patient populations. The investigators plan to conduct additional research to determine consistency between different types of orthopaedic procedures in octogenarians versus non-octogenarians.
Varghese PP, Chen C, Gordon AM, Ashraf A, Ng MK-S, Magruder M, Roche MW. Complications, Readmission Rates, and In-Hospital Lengths of Stay Rates in Octogenarian vs. Non-Octogenarians: An Analysis of Over 1.7 Million Patients (Poster P0120). Presented at the American Academy of Orthopaedic Surgeons’ 2022 Annual Meeting, March 22-26, 2022, Chicago, Illinois.
- Sloan M, Premkumar A, Sheth NP. Projected volume of primary total joint arthroplasty in the U.S., 2014 to 2030. JBJS. 2018; 100 (17):1455-1460. Accessed March24, 2022.