Each year, more than 650,000 Americans with osteoarthritis of the knee undergo arthroscopic surgery in the hopes of relieving their knee pain and improving their knee function. But, research published in the July 11, 2002 issue of
The New England Journal of Medicine
suggests that arthroscopy is no more effective in relieving pain or improving knee function than a sham procedure in which incisions are made but no surgery is performed.
About the study
Researchers at the Veterans Affairs Medical Center and Baylor College of Medicine, both in Houston, Texas, enrolled 180 people with osteoarthritis of the knee. Participants were age 75 or younger and more than 90% were men. They all reported at least moderate knee pain and had undergone medical treatment without success for at least six months. People were excluded from the study if they had extremely severe arthritis, severe deformity in the knee joint, other serious medical conditions, or had previously undergone arthroscopy of the knee.
Participants were randomly assigned to receive one of three procedures:
Arthroscopic lavage –
the surgeon made incisions in the knee and examined the inside of the knee with an arthroscope; fluid was then flushed through the knee joint to remove any debris
Arthroscopic debridement –
the surgeon made incisions in the knee and examined the inside of the knee with an arthroscope; fluid was then flushed through the knee joint to remove any debris and the surgeon shaved off rough cartilage and removed further debris
Placebo procedure –
a simulated surgery in which the surgeon made the usual incisions and then asked for all the appropriate instruments and pretended to operate for the same length of time as the real procedures
Participants reported their pain and knee function (such as walking and bending) at 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years after the procedure. In addition, researchers assessed knee function by measuring the time it took for participants to walk 100 feet and to climb up and down a flight of stairs.
Researchers compared the pain and knee function of people in the lavage, debridement, and placebo groups.
Patients in the lavage and debridement groups did not report any less pain or better knee function than patients in the placebo group. This was true for all assessments: 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years after the procedure.
Although these results are interesting and seem to indicate that arthroscopy is not an effective treatment for osteoarthritis of the knee, this study has its limitations. First, because more than 90% of participants were men, it’s not clear whether these results apply to women, though there is currently no reason to think that women respond any differently to arthroscopy. Second, the arthroscopic procedures performed did not include abrasion arthroplasty or microfracture of the articular surface. Therefore, this study does not address the effectiveness of these procedures, which are sometimes performed during an arthroscopic procedure. Third, in selecting patients for this study, the researchers did not consider body mass, age, joint alignment, excess joint fluid, and inflammation of the joint lining—factors that some arthroscopists believe could affect the success of the procedure.
How does this affect you?
Does this mean knee arthroscopy doesn’t work? That depends on what type of arthroscopy and what your condition is. The findings of this study suggest that arthroscopic lavage and debridement are probably not effective in relieving pain and improving knee function in people with osteoarthritis of the knee. It also suggests that the act of having a sham surgical procedure can decrease the pain and disability associated with osteoarthritis. This phenomenon, known as the placebo effect, is identical to the improvement of symptoms often observed when patients unknowingly take inactive pills.
It’s important to understand that the term arthroscopy refers to a number of different procedures in which an arthroscope is used to examine the inside of the knee or other joints. Other types of arthroscopy for other medical conditions may be effective procedures even if arthroscopic lavage and debridement don’t help people with osteoarthritis of the knee.
Moseley JB, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee.
New England Journal of Medicine.
July 11, 2002;347(2):81-88.
Felson DT and Buckwalter J. Debridement and lavage for osteoarthritis of the knee.
New England Journal of Medicine.
July 11, 2002;347(2):132-133.
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substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
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