WebMD Medical News
Louise Chang, MD
Oct. 20, 2008 -- Roughly 300,000 knee replacement surgeries are performed
each year in the U.S., and while most patients do well, some have lingering pain even when the operation is
But a strategy developed at Chicago's Rush Medical Center appears to
significantly reduce chronic pain following knee surgery.
Rush researchers report that patients treated with the fibromyalgia drug Lyrica immediately before
surgery and for two weeks afterward had significantly less chronic pain six
months later, compared with patients who were not treated with the drug.
Anesthesiologist and study lead author Asokumar Buvanendran, MD, tells WebMD
that it is increasingly clear that drugs given at the time of surgery can have a long-term
effect on pain.
"We showed that treating patients immediately before and after surgery
was associated with long-term improvements in pain control and quality of
life," he says.
Buvanendran says it is not uncommon for patients to develop chronic pain
after surgery, but the condition is poorly understood and underdiagnosed.
Studies suggest that between 1% and 10% of patients who have knee replacement surgery have
lingering, long-term pain that is not associated with the arthritis or other conditions
that lead to surgery.
Known as chronic neuropathic (nerve-related) pain, the condition has been
difficult to treat precisely because there is no widely agreed upon
"Many physicians don't even recognize it and that is why patients often
end up going from doctor to doctor to get help," he says.
In June 2007, Pfizer's epilepsy drug Lyrica became the
first approved treatment for the chronic pain condition fibromyalgia. It is
also approved for the treatment of chronic pain caused by diabetic nerve
According to Pfizer, the drug works by targeting the pain-causing electrical
signals in damaged nerves.
With this in mind, the Rush researchers got the idea to treat patients with
the drug around the time of surgery in an effort to prevent chronic
nerve-related pain later on.
Buvanendran reported the results of the first randomized trial of the
strategy Sunday at the 2008 Annual Meeting of the American Society of
Anesthesiologists in Orlando, Fla. The study was funded in part by Pfizer.
The study involved 240 patients undergoing knee replacement surgery who were
divided into two groups.
Half the patients were treated with 300 milligrams of Lyrica two hours
before surgery and 150 milligrams of the drug twice a day for two weeks
following surgery. The rest of the patients received placebo treatments given
at the same time intervals.
Neither the patients nor the doctors and nurses administering the drugs knew
which treatment the patients were getting. All the study participants also
received standard pain medication following surgery.
Six months after surgery, there were no complaints of chronic neuropathic
pain among patients treated with the fibromyalgia drug, while 5.3% of
placebo-treated patients continued to have pain.
The Lyrica-treated patients also had a greater range of motion in surgically
treated knees following surgery.
Buvanendran says the drug is now routinely given to patients undergoing knee
replacement surgery at Rush University Medical Center.
Rush surgeon Aaron G. Rosenberg, MD, tells WebMD that the study is not the
first to show that drugs given to patients around the time of surgery can
improve long-term outcomes.
Rosenberg was not involved with the latest trial, but he did participate in
a 2003 study which showed improved long-term outcomes among knee replacement
patients treated with a Cox-2-type pain reliever immediately before and after
"We showed that patients treated for a couple of weeks with a relatively
cheap anti-inflammatory had better range of motion a month after surgery,"
he says. "That is important because the quicker knee surgery patients get
moving the better."
SOURCES:Annual Meeting of the American Society of Anesthesiologists, Orlando, Fla.,
Oct. 18-22, 2008.Asokumar Buvanendran, MD, associate professor of anesthesiology; director of
orthopedic anesthesia, Rush Medical College, Chicago.Aaron G. Rosenberg, MD, professor of surgery, Rush Medical College,
Chicago.American Academy of Orthopaedic Surgeons.The Journal of the American Medical Association, 2003; vol 290: pp
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