Researchers found that the drug pregabalin, when administered before and after total knee replacement surgery significantly decreased the incidence of chronic pain while increasing and expediting patient mobility after surgery.

“While TKR is an effective surgical treatment one of the complications is chronic pain, a debilitating condition that can lead to a substantial reduction in quality of life with few effective treatment options,” said Asokumar Buvanendran, M.D., associate professor of anesthesiology and director of orthopedic anesthesia at Rush Medical College, Chicago, Illinois. “Searching for ways to improve the patient surgical experience, we evaluated pregabalin for effectiveness not as a treatment for chronic pain, but as a preventative of chronic neuropathic pain after surgery.”

For the trial 240 patients having knee replacement were divided into two groups. Half of the patients received 300 milligrams of pregabalin two hours before surgery and repeated doses of 150 milligrams of pregabalin twice a day for 14 days following surgery. The remaining patients received a matching placebo at the same time intervals. After surgery all patients received pain medication through a catheter using a patient controlled epidural device (PCEA).

The principal finding of the study was the dramatic decrease in the incidence of chronic neuropathic pain in patients who received pregabalin. Six months following surgery, 0 percent of patients in the pregabalin group reported the incidence of chronic pain compared to 5.3 percent of patients in the placebo group.

In addition patients that received pregabalin experienced a greater knee range of motion (ROM) following surgery with the ability to perform simple tasks when returning home such as climbing stairs with a ROM of 85 degrees compared to a ROM of 79 degrees for the placebo group. Patients can climb stairs at 83 degrees of knee flexion, descend stairs at 90 degrees and rise from a chair at 90 degrees.

“This is the first large prospective clinical trial examining the incidence of chronic pain after TKR and defining strategy to prevent the development of this debilitating chronic pain syndrome,” said Buvanendran. “With the promising treatment of pregabalin, patients may no longer delay needed orthopedic surgery for fear of pain after surgery and delayed rehabilitation.”

About Osteoarthritis

Osteoarthritis also known as degenerative arthritis, degenerative joint disease), is a condition in which low-grade inflammation results in pain in the joints, caused by abnormal wearing of the cartilage that covers and acts as a cushion inside joints and destruction or decrease of synovial fluid that lubricates those joints. As the bone surfaces become less well protected by cartilage,  pain is experienced upon weight bearing, including walking and standing. Due to decreased movement because of the pain, regional muscles may atrophy, and  ligaments may become more lax.

"Osteoarthritis" is derived from the Greek word "osteo", meaning "of the bone", "arthro", meaning "joint", and "itis", meaning inflammation, although many sufferers have little or no inflammation.  Osteoarthritis affects nearly 21 million people in the United States, accounting for 25% of visits to primary care physicians, and half of all NSAID (Non-Steroidal Anti-Inflammatory Drugs) prescriptions. More than 10 million Americans have a total joint replacement each year.

A common misconception is that osteoarthritis is due solely to wear and tear, due to the fact that osteoarthritis typically is not present in younger people. However, while age is correlated with osteoarthritis incidence, this merely illustrates that osteoarthritis is a process that takes time to develop. There is usually an underlying cause for osteoarthritis, in which case it is described as secondary osteoarthritis. If no underlying cause can be identified it is described as primary osteoarthritis. "Degenerative arthritis", often used as a synonym for osteoarthritis, but the latter involves both degenerative and regenerative changes.

It is estimated that 80% of the population will have radiographic evidence of osteoarthritis by age 65, although only 60% of those will be symptomatic.

About the American Society of Anesthesiologists

Physicians providing the lifeline of modern medicine. Founded in 1905, the American Society of Anesthesiologists is an educational, research and scientific association with 43,000 members organized to raise and maintain the standards of the medical practice of anesthesiology and improve the care of the patient. For more information visit the American Society of Anesthesiologists Web site at http://www.asahq.org.