The study shows that the strongest predictors for severe postoperative pain during rest included being female; © panthermedia.net/Tatiana Gladskikh
Middle-aged women with rheumatoid arthritis or arthritis resulting from an injury are among the patients most likely to experience serious pain following a knee replacement, researchers from Hospital for Special Surgery (HSS) in New York have found.
One of the biggest concerns patients have is the amount of pain they will have after knee replacement surgery. Although it is a very successful operation overall to relieve arthritis pain and restore function, persistent postoperative pain can be a problem for some patients. Researchers at HSS set out to determine which groups were at highest risk for increased postoperative pain based on demographic and surgical variables.
"There is no question that pain after total knee replacement is greater than that after total hip replacement," says senior study author Dr. Thomas P. Sculco. "Many factors play a role, and our studies found that younger female patients, particularly those with post-traumatic or rheumatoid arthritis, had the highest pain scores."
In two companion studies, Sculco and colleagues also found that surgical factors like having general anesthesia or a longer tourniquet time during knee replacement also can contribute to pain following surgery.
For the studies, the researchers reviewed hospital records for 273 patients who underwent total knee replacement from October 2007 to March 2010. For the first study, investigators looked at demographic data such as gender, ethnicity, age, height, weight, type of knee arthritis and co-existing medical conditions. They also looked at the knee's preoperative range of motion, how well the patients could walk and the amount of pain they had before surgery.
The strongest predictors for severe postoperative pain during rest included being female; being between the ages of 45 and 65; having post-traumatic arthritis spurred by an injury, rheumatoid arthritis, or osteoarthritis; being obese; and having a higher level of pain at the time of hospital admission. Patients with avascular necrosis, a disease that causes cell death of bone components due to a decreased blood supply, had significantly lower postoperative pain.
During periods of activity, obesity, a higher pain level during hospital admission and being between the ages of 45 and 65 were the strongest predictors of postoperative pain. Patients who were Asian or Caucasian, and those with either underlying osteoarthritis or avascular necrosis, or both, had lower postoperative pain during periods of activity.
"Before patients come in to the hospital, surgeons should have a thorough discussion with them regarding postoperative pain, particularly in the groups that we found tended to have more pain," Sculco says. "More aggressive pain management techniques may be necessary for these patients."
MEDICA.de; Source: Hospital for Special Surgery (HSS)