Total Knee Replacement is Very Cost-Effective in the US Medicare-Aged Population

High-volume health centers confer greater value per dollar spent compared to low-volume centers.

Boston, MA, July 08, 2009 --( Each year nearly 500,000 total knee replacements (TKR) are performed in the US at a cost exceeding $11 billion. Due to the aging population, projections indicate dramatic increases in TKRs over the next two decades. Researchers at Brigham and Women's Hospital (BWH) have found that TKR in US Medicare-aged population is very cost-effective, across various patient risk levels for post-surgical complications. Further results note that TKR performed at a high-volume health center yields better value compared to those performed at lower volume centers. This research appears in the June 22, 2009 issue of Archives of Internal Medicine.

The researchers examined whether cost-effectiveness of TKR is affected by patients’ surgical risk and the volume of TKRs performed at the procedure site. The study showed that TKR shows consistent success and cost-effectiveness across all surgical risk groups and that TKR was more costly and less effective in low-volume than high-volume centers.

“Because health care expenditures related to TKR are substantial, it is critical to understand the value obtained for the money spent on TKR,” said Elena Losina, PhD, co-director of Orthopedics and Arthritis Center for Outcomes Research in the Department of Orthopedic Surgery at BWH, associate professor of orthopedics, Harvard Medical School, and lead author of the study. Dr. Losina and colleagues developed a mathematical model to simulate the outcomes of end stage knee osteoarthritis in a Medicare population with and without TKR. In addition to pain relief, the model considered adverse events including surgical complications and prosthesis failure.

Researchers found that TKR added on average 1.1 quality adjusted years (QALYs) per patient receiving the procedure and increased costs by about $20,000, yielding a cost-effectiveness ratio of $18,300/QALY gained. According to US thresholds, TKR appears to be very cost-effective. In other words, for every $18,300 in costs associated with total knee replacement, one individual would gain one additional quality adjusted year of life because of the TKR. “Importantly, results do not necessarily suggest that a person will live longer but rather that they will experience improvement in the quality of each year lived," said Dr. Losina, who is also an adjunct associate professor of Biostatistics at Boston University School of Public Health.

“This work is a natural continuation of our previous research where we found that mortality rates, and risk for postoperative complications, and failure of the knee replacement generally decrease for those who have the procedure at a high-volume center,” said Jeffrey N. Katz, MD, director of the Orthopedic and Arthritis Center for Outcomes Research at BWH, and senior study author .

"Medicare patients and their referring physicians should consider these findings when discussing TKR options for knee osteoarthritis. Higher volume centers lead to better outcomes and confer a better value” said Dr. Losina. “Having a TKR in low-volume hospital is, however, preferable to not having TKR at all, as TKR at a low-volume hospital still provides tangible improvement in quality of life and confers a good value for cost."

This study was funded by grants from National Institute of Arthritis, Musculoskeletal and Skin Disease and the Arthritis Foundation. Contributing authors include Rochelle P. Walensky, MD, MPH, Courtenay L. Kessler, MS, Parastu S. Emrani, William M. Reichmann, MA, Elizabeth A. Wright, PhD, Holly L. Holt, Daniel H. Solomon, MD, MPH, Edward Yelin, PhD, A. David Paltiel, PhD and Jeffrey N. Katz, MD, MS.

About Brigham and Women's Hospital:-
Brigham and Women's Hospital (BWH) is a 777-bed nonprofit teaching affiliate of Harvard Medical School and a founding member of Partners HealthCare, an integrated health care delivery network. In July of 2008, the hospital opened the Carl J. and Ruth Shapiro Cardiovascular Center, the most advanced center of its kind. BWH is committed to excellence in patient care with expertise in virtually every specialty of medicine and surgery. The BWH medical preeminence dates back to 1832, and today that rich history in clinical care is coupled with its national leadership in quality improvement and patient safety initiatives and its dedication to educating and training the next generation of health care professionals. Through investigation and discovery conducted at its Biomedical Research Institute (BRI), BWH is an international leader in basic, clinical and translational research on human diseases, involving more than 860 physician-investigators and renowned biomedical scientists and faculty supported by more than $416 M in funding. BWH is also home to major landmark epidemiologic population studies, including the Nurses' and Physicians' Health Studies and the Women's Health Initiative. For more information about BWH, please visit

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