Compared with older patients being evaluated for total knee arthroplasty (TKA), younger patients – those under age 60 – have similar pain, disability, and willingness to undergo surgery, according to a study published online ahead of print by The Journal of Bone & Joint Surgery.
However, because younger also tend to have higher rates of potential risk factors for complications, orthopaedic surgeons may be less likely to recommend TKA for this patient population.
To find out how patient age and age-related characteristics affect recommendations for TKA, the BEST-Knee Study Team in Canada analyzed data from 2037 patients with knee osteoarthritis (OA) who were evaluated for possible TKA at 2 arthroplasty centers between 2014 and 2016. Factors related to the appropriateness of TKA included:
- Need for TKA, based on knee symptoms and prior treatment
- Readiness/willingness to undergo TKA
- Health status, including risk factors for complications following TKA
- Expectations for the results of TKA
About one fourth of patients were under age 60: 22.7% were age 50 to 59 and 3.3% were younger than age 50. The younger patients had more severe pain and worse physical function compared with patients age 60 or older, and were more likely to rate their knee symptoms as “unacceptable.” In all age groups, more than 92% of patients said they were “definitely willing” to undergo TKA.
Expected outcomes of TKA also differed by age. Patients under age 60 were more likely to say that improved ability to exercise and participate in sports was a “very important” outcome of TKA. In contrast, older patients were more likely to cite less-demanding outcomes, such as going up and down stairs and being able to straighten the leg.
Patients in the younger age groups had higher rates of severe obesity and smoking. Obesity is a key risk factor for osteoarthritis, while smoking increases the risk of complications following TKA surgery.
After evaluation, orthopaedic surgeons recommended TKA for 73.6% of patients overall:
- 2% for patients under age 50
- 0 % for patients age 50 to 59
- 4% for patients age 60 or older
The effects of age were lessened after adjustment for other factors. In particular, surgeons were more likely to recommend TKA for patients with greater need, based on pain scores and ability to cope with symptoms, and in patients with greater willingness to undergo the procedure.
However, surgeons were less likely to recommended surgery for patients with more-demanding expectations, such as returning to sports or other vigorous activities. Consistent with the increased complication risk due to smoking, surgeons were less likely to recommend TKA for patients who smoked.
“Orthopaedic surgeons have to balance the patient’s clinical need and willingness with the risk for complications and revision,” said study co-author Gillian A. Hawker, MD, MSc, from the University of Toronto. “When they factored all these things in together, they were just as likely to offer surgery to younger versus older people.”
At a time when TKA rates are rising fastest in patients under age 60, “incorporation of TKA appropriateness criteria into TKA decision-making may facilitate consideration of TKA benefits and risks in a growing population of young, obese individuals with knee OA,” the study authors concluded.
“Whether the short- and longer-term risks of TKA are outweighed by the benefits is unclear and warrants additional research,” Dr. Hawker said.
Hawker GA, Bohm E, Dunbar MJ, et al. The effect of patient age and surgical appropriateness and their influence on surgeon recommendations for primary TKA: a cross-sectional study of 2,037 patients. J Bone Joint Surg Am. 2022 Feb 28. doi: 10.2106/JBJS.21.00597. Online ahead of print.