Many Knee Replacements May Be Unnecessary

Total knee replacement surgery for arthritis patients may be inappropriate in many cases

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) For some patients with arthritis, knee replacement may eventually seem like the only option for treating their pain. But a new study suggests this treatment may not always be appropriate.

The study analyzed cases of total knee replacement by looking at a number of different aspects of the patients' cases, including their age, symptoms and information gathered from X-rays.

The study found that a third of total knee replacements examined were determined to be inappropriate.

"Talk to your rheumatologist about low-impact exercise options."

According to the American Academy of Orthopedic Surgeons, total knee replacement surgery that replaces the original knee joint can ease pain and improve mobility in those coping with arthritis or an injury.  

The researchers behind this new study, who were led by Daniel L. Riddle, PT, PhD, of the Department of Physical Therapy at Virginia Commonwealth University in Richmond, aimed to explore how many of these total knee replacement surgeries could be classified as appropriate, inconclusive or inappropriate.

To do so, Dr. Riddle and team used data from the Osteoarthritis Initiative study to examine 175 patients who had undergone total knee replacement. The patients had an average age of 66.9 years old.

A number of measures were used to provide insight into the patients prior to their surgery, including knee motion measures, knee X-rays, analysis of their arthritis case and scales called the WOMAC Pain and Physical Function scales.

The WOMAC scales measure 22 different items for a total score that represents intensity of symptoms. Dr. Riddle and team then used these scores to categorize the patients' symptoms as moderate, intense or severe.

After analyzing all the information, the researchers determined that 44 percent of the total knee replacements were appropriate, 21.7 percent were inconclusive and 34.3 percent were inappropriate.

The 77 patients who had total knee replacements considered "appropriate" by the researchers tended to have intense or severe symptoms, have limited mobility and be age 55 or older.

The 38 patients in the "inconclusive" category involved a number of situations, including having intense or severe symptoms, but having normal mobility or being under the age of 55.

The 60 patients who had "inappropriate" total knee replacements tended to have slight or moderate symptoms and less certain evidence that their arthritis called for the surgery.

"These data support the need for consensus development of criteria for patient selection among practitioners in the US treating potential [total knee replacement] candidates," concluded Dr. Riddle and team.

It is important to note that this study examined a relatively small number of participants and that the proper age for total knee replacement candidates (i.e., above or below age 55) is an area that is still being discussed. Further research is needed to confirm these findings.

This study was published online June 30 in Arthritis & Rheumatology. No conflicts of interest were reported.

The study relied on data from the Osteoarthritis Initiative study, which was funded by a number of sources, including the National Institutes of Health, Merck Research and Pfizer, Inc.

Review Date: 
June 26, 2014
Last Updated:
June 30, 2014