Pain Forecast after Total Knee Replacement Surgery

Anxiety and depression have been linked to pain after total knee replacement (TKR). Doctors at the Northwestern Orthopedic Institute in Illinois are looking for ways to reduce pain after TKR. They studied 116 patients before and after surgery to find risk factors that predict pain. If they can tell who might be affected and why, they may be able to prevent the pain.

The researchers measured pain, stiffness, and physical function. They also took X-rays. Another test showed symptoms of anxiety and depression. They asked each patient about current life stress. Results showed a typical pain pattern after TKR. Most patients reported that pain intensity was cut in half three months after the surgery. About 25 percent still had significant pain after three months. By one year, one in eight patients had pain despite normal test findings.

Patients who had pain that lasted beyond the expected time after TKR tended to have symptoms of depression and anxiety before the operation. Patients with the most depression beforehand had the worst pain a year after surgery. How does knowing this help doctors and patients? Simple screening can be done with every patient before TKR. Anxious patients can learn coping skills before the operation. A class in relaxation is advised. Physicians can follow patients who have high distress scores more closely.

The authors suggest that patients with a high stress profile see a psychologist to deal with depression before having TKR surgery. They say doctors should treat pain sooner in patients with anxiety or depression. Taking steps to reduce psychologic stress before TKR surgery may result in less pain and better function after the operation.



References: Victoria A. Brander, MD, et al. Predicting Total Knee Replacement Pain. In Clinical Orthopaedics and Related Research. November 2003. Vol. 416. Pp. 27-36.