How Effective Is TKA?
A new study suggests that total knee arthroplasty may have only a minimal effect on quality of life and may not be cost-effective for all patients who undergo the procedure.
Orthopaedic surgeons generally consider total knee arthroplasty (TKA) to be an effective procedure that relieves the pain of knee osteoarthritis (OA) and restores physical functioning.
A study recently published in the BMJ comes to a different conclusion, suggesting that overall, TKA provides only minimal improvement in quality of life and is economically unattractive because the procedure is performed in too many patients.
If it were limited to patients with more severe symptoms, however, its effectiveness – and economic attractiveness – would rise, they say.
“Given its limited effectiveness in individuals with less severely affected physical function, performance of total knee replacement in these patients seems to be economically unjustifiable,” said Bart Ferket, MD, PhD, Assistant Professor, Department of Population Health Science and Policy at the Icahn School of Medicine at Mount Sinai and lead author on the study.
“Considerable cost savings could be made by limiting eligibility to patients with more symptomatic knee osteoarthritis. Our findings emphasize the need for more research comparing total knee replacement with less expensive, more conservative interventions, particularly in patients with less severe symptoms.”
About 12% of adults in the United States have knee OA. The annual rate of total knee replacement has doubled since 2000, mainly due to expanding eligibility to patients with less severe physical symptoms. The number of procedures performed each year now exceeds 640,000 at a total annual cost of about $10.2 billion.
For the study, researchers from the Icahn School of Medicine at Mount Sinai and Erasmus University Medical Center in Rotterdam, The Netherlands, wanted to evaluate the impact of TKA on quality of life in people with knee OA. They also wanted to estimate differences in lifetime costs and quality adjusted life years (QALYs) according to level of symptoms.
They analyzed data from 2 US cohort studies:
- 4,498 participants from the Osteoarthritis Initiative (OAI) who were ages 45 to 79 years, had knee OA or were high risk of developing it, and who were followed for up to 9 years
- 2,907 patients from the Multicenter Osteoarthritis Study (MOST) who were followed up for 2 years
Quality of life was measured using a recognized score of physical and mental function – the SF-12 – and using OA-specific quality of life scores.
The researchers found that quality of life outcomes generally improved after TKA, although the effect was small. Improvements were found to be higher in patients with lower preoperative physical function scores.
In a cost-effectiveness analysis, current practice was more expensive and in some cases seemed less effective compared with scenarios in which TKA was performed only in patients with lower physical function scores.
“Our findings show opportunity for optimizing delivery of total knee replacement in a cost-effective way: finding the patients who will benefit the most, delivering the treatment at the correct point in their disease progression, and optimizing the cost so we can deliver the benefit to all who need it,” said Madhu Mazumdar, PhD, Director of the Institute for Healthcare Delivery Science at the Mount Sinai Health System, Professor of Biostatistics, Department of Population Health Science and Policy at the Icahn School of Medicine at Mount Sinai, and co-author of the study.
Ferket BS, Feldman Z, Zhou J, Oei EH, Bierma-Zeinstra SM, Mazurdam M. Impact of total knee replacement practice: cost effectiveness analysis of data from the Osteoarthritis Initiative. BMJ. 2017 Mar 28;356:j1131. doi: 10.1136/bmj.j1131.