Knee Replacement for Elderly Also Lowers Risk of
Death and Heart Failure
It does, however, cost Medicare a little more than treating those osteoarthritis patients who did not choose the replacement
About Knee Replacement
By American Academy of Orthopaedic Surgeons
most common cause of chronic knee pain and disability is arthritis. Although there are many types of arthritis, most knee pain is
caused by just three types: osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis.
● Osteoarthritis. This is an age-related "wear and tear"
type of arthritis. It usually occurs in people 50 years of age and older, but may occur in younger people, too. The cartilage that
cushions the bones of the knee softens and wears away. The bones then rub against one another, causing knee pain and stiffness.
● Rheumatoid arthritis. This is a disease in which the
synovial membrane that surrounds the joint becomes inflamed and thickened. This chronic inflammation can damage the cartilage and
eventually cause cartilage loss, pain, and stiffness. Rheumatoid arthritis is the most common form of a group of disorders termed
● Post-traumatic arthritis. This can follow a serious
knee injury. Fractures of the bones surrounding the knee or tears of the knee ligaments may damage the articular cartilage over time,
causing knee pain and limiting knee function.
knee replacement (also called knee arthroplasty) might be more accurately termed a knee "resurfacing" because only the surface of the
bones are actually replaced.
There are four basic steps to a knee replacement procedure.
● Prepare the bone. The damaged cartilage surfaces at the
ends of the femur and tibia are removed along with a small amount of underlying bone.
● Position the metal implants. The removed cartilage and
bone is replaced with metal components that recreate the surface of the joint. These metal parts may be cemented or "press-fit" into
● Resurface the patella. The undersurface of the patella
(kneecap) is cut and resurfaced with a plastic button. Some surgeons do not resurface the patella, depending upon the case.
● Insert a spacer. A medical-grade plastic spacer is
inserted between the metal components to create a smooth gliding surface.
Candidates for Surgery
There are no absolute age or weight restrictions for total knee replacement surgery.
Recommendations for surgery are based on a patient's pain and disability, not age.
Most patients who undergo total knee replacement are age 50 to 80, but orthopaedic
surgeons evaluate patients individually.
Total knee replacements have been performed successfully at all ages, from the young
teenager with juvenile arthritis to the elderly patient with degenerative arthritis.
Feb. 7, 2012 – Elderly patients needing a total knee replacement (TKR) due to
osteoarthritis have new reasons to say, “Yes.” Research presented at the annual
meeting of the American Academy of Orthopaedic Surgeons says the operation not only repairs the knee, it also lowers the patient’s probability
of heart failure and death.
The purpose of this study however, was to compare differences in cost and health outcomes between osteoarthritic patients
who undergo joint replacement therapy and those who do not. They found that it did cost Medicare a little more for the patients that received
the TKR than for those who did not.
Investigators reviewed Medicare records to identify osteoarthritis patients, separating them into two groups – those who
underwent TKR to relieve symptoms, and those who did not.
Outcomes of interest included average annual Medicare payments for related care, mortality, and new diagnoses of
congestive heart failure, diabetes and depression.
Differences in costs and risk ratios were adjusted for multiple variables including age, sex, race and region. The
results (adjusted for underlying health conditions) were compared at fixed periods of one year, three years, five years and seven years after
The seven-year cumulative average Medicare payments for all treatments were $63,940 for the non-TKR group, and $83,783
for the TKR group, for an incremental increased seven-year cost of $19,843.
It was suggested that one thing that may narrow this difference is the cost of prescription drugs, which were not
included in the study but are reportedly “much higher” for the non-TKR group.
There were significant positives in the osteoarthritis TKR group:
● the risk of mortality was half that of the non-TKR group and
● the congestive heart failure rate also was lower, at three, five and seven years after surgery.
There was no difference in diabetes rates among both groups.
Depression rates were slightly higher in the TKR group during the first three years after surgery, though there was no
difference at five and seven years.
“These patients had improved survivorship and reduced risk for cardiovascular conditions,” said Scott Lovald, PhD, MBA,
lead investigator and senior associate at Exponent, Inc.
“More specifically, total knee replacement in osteoarthritis patients may reduce patient mortality by half. There are few
health care investments that are so cost effective.”
Disclosures: Scott Lovald, PhD, has nothing to disclose in relation to this study.