Knee replacements hold up well after 20 years

Knee replacement surgery has become common in the last 30 years, and more younger people with bad knees are considering the surgery. A study presented Wednesday at the American Academy of Orthopaedic Surgeons annual meeting may reassure them that the replacement should hold up for a long time.

Researchers evaluated 128 people who had lived at least 20 years after total knee replacement surgery. The patients’ average age at the time of surgery was 63. The average age at the post-20-year follow-up was 82. The study found that almost all of the patients had good physical function. Most could walk at least five blocks, and half said they had “unlimited” walking ability. All but two could walk up and down stairs. None of the patients had experienced an implant failure.

“Elderly people are using their surgically replaced knees for fairly active lifestyles many years after surgery,” the lead author of the study, Dr. John B. Meding, said in a news release. Meding is an attending orthopedic surgeon at The Center for Hip and Knee Surgery in Mooresville, Ind.

In other news from the AAOS meeting:

• A study found that revision surgery for total hip replacements was linked to a younger age at the time of surgery, being male and surgery performed by doctors without as much experience in the procedure. The study is the first to look at total hip replacement surgery revision rates after 12 or more years. Total hip replacement is increasingly being done on younger patients, the authors said.

• Another study on revision hip replacement surgery found that the surgery clearly helps people age 80 or older; however, such elderly patients are at higher risk of complications and death. Among a study of 325 people with hip revisions, the death rate in people 80 and older was 6% in the three months following surgery compared with no deaths among people younger than 80. Medical complications were seen in 22.6% of those age 80 and older compared with 6.6% in people younger than 80.

Related: Imaging tests are often done for the doctor -- not the patient.

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