Study finds TKA cost-effective for end-stage knee arthritis regardless of patient risk

The cost-effectiveness of TKA was comparable to that of ACL reconstruction, lumbar discectomy and total hip replacement.

Total knee arthroplasty is a cost-effective treatment option for patients with end-stage knee arthritis, even in high-risk patients, according to a study presented at the American College of Rheumatology annual meeting.

"We found that TKA (total knee arthroplasty) represents an effective and very cost-effective option for all patients with knee arthritis, not just those whom we might label 'ideal' candidates," said Elena Losina, PhD, lead author of the study, in a press release.

"While it has been shown that higher volume facilities deliver better outcomes at lower cost, we would like to stress that TKA remains an attractive treatment option even in lower-volume settings. TKA delivers better value than many other widely accepted musculoskeletal procedures, such as lumbar discectomy and fusion of the spine for spondylolisthesis."

Losina and colleagues at Brigham and Women's Hospital, Boston, and several other U.S. institutions investigated the cost-effectiveness of TKA for treating low- and high-risk patients with end-stage knee arthritis. They also examined whether hospital volume affected the cost-effectiveness assessments.

The researchers developed a Markov state-transition computer simulation model of treatment options. The analyses focused on the overall U.S. population of patients with knee arthritis as well as subgroups of patients considered low-, medium- or high-risk, according to the study.

"Patient risk was defined based on the likelihood of perioperative complications," the study authors said. "We considered four competing strategies for each group: no TKA and undergoing TKA in low-, medium- and high-volume centers."

Investigators derived perioperative and longer-term TKA outcomes using Medicare claims and survey data, and derived costs from National Health and Nutrition Examination Survey data, published literature and Medicare reimbursement schedules, according to the study.

The researchers found that, for the general population with a mean age of 73 years, TKA increased life expectancy from 4.2 to 6.7 quality-adjusted life-years (QALY). However, lifetime costs increased from $29,000 without surgery to $42,500 after TKA, yielding a cost-effectiveness ratio of $5,320 per QALY, the investigators wrote.

"In the worst-case scenario (high-risk patients receiving TKA in a low-volume center) the cost-effectiveness ratio was $10,900/QALY," they said.

"TKA in low-volume centers was a dominated strategy (higher cost, lower effectiveness) compared to having TKA in higher-volume centers. Results were most sensitive to improvement in quality of life after successful TKA, cost of TKA and cost of living with end-stage knee arthritis," they said.

"For persons with end-stage knee arthritis, TKA is very cost-effective, even for high-risk patients and patients who undergo TKA in low-volume centers," the authors said. "The cost-effectiveness of TKA is comparable to the cost-effectiveness of [anterior cruciate ligament] reconstruction, lumbar discectomy and total hip replacement, and lies well below established willingness-to-pay thresholds in the U.S."

For more information:
Losina E, Kessler CL, Walensky RP, et al. Cost-effectiveness of total knee replacement (TKR) in the U.S.: Impact of patient risk and hospital volume. #84. Presented at the American College of Rheumatology Annual Scientific Meeting. Nov. 6-11, 2007. Boston.