PREP-ping for knee replacement
An innovative pre-surgery exercise program could aid recovery for people who have had knee replacements.
Story by Laura Ly/Photos by Veer and Trudie Lee
Total knee-replacement surgery is an option for patients with arthritic pain and mobility problems; in particular, people suffering from end-stage osteoarthritis. After surgery, patients undergo rehabilitation to regain knee mobility and strength. But what happens when patients with severely limited knee mobility undergo rehabilitation before surgery? AHFMR Population Health Investigator Dr. Allyson Jones aims to find out.
Dr. Jones is the principal investigator of the Preoperative Rehabilitation Exercise Program, aptly known as the PREP study. She explains, "With earlier studies, we found that patients' activity level or functional level prior to surgery predicted how well they recovered six months after total knee-replacement surgery. Based on that work, we want to see if we can maintain or improve a patient's functional level while they wait for surgery." Functional level is measured by a person's ability to perform basic daily activities such as walking and climbing stairs.
The program is designed for a particular subgroup of patients undergoing knee replacements: those with the lowest functional level and the most difficulty with pain. Participants in the study will be randomly divided into two groups. Members of one group will be assigned a home exercise program, administered by a physiotherapist, for eight weeks prior to surgery. The program will work on managing pain, increasing strength and overall mobility, and extending range of motion in the knee. At week four the physiotherapist will measure progress and adjust the exercise program accordingly. In the other group, members will prepare for surgery without this exercise program. "Patients in both groups will have a physiotherapist phone them on a weekly basis to see how they are managing," says Dr. Jones.
Participants are currently being recruited through the Alberta Hip and Knee Clinic in Edmonton; 230 patients will be involved. "We are recruiting patients as they are seen by the orthopedic surgeon. We assess them nine to ten weeks before surgery, and again before hospital admission when the exercise group have completed their program. Then we follow them up at one, three, and six months post-operatively," Dr. Jones explains. During the follow-up assessments, patients will answer questions about their pain, their mobility, and their overall health status. They will also be asked to perform knee and arm exercises to measure their range of motion, muscle strength, and agility.
Epidemiologists, rheumatologists, orthopedic surgeons, health economists, and pharmacists are also involved in the study. As Dr. Jones explains, research projects in the area of clinical rehabilitation often involve multidisciplinary teams. "It's all part and parcel with the type of research we are doing. It's a great team effort."
A future related study may target patients who are waiting for knee replacements but who have a higher level of function than those involved in the first PREP study. "We want to evaluate patients waiting for their surgery who, while still having functional limitations, can perform a more aggressive exercise program."
Ultimately, Dr. Jones and her colleagues want to develop a preoperative exercise program that will be the most beneficial to the recovery of patients with knee replacements. Dr. Jones says that "it's often a challenge to rehabilitate patients who have had total knee replacements. Helping patients regain joint mobility and strength, and return to regular activity involves a lot of work during the post-operative period. Basically, we want to identify optimal exercise programs for patients while they wait for surgery."
Dr. Jones argues that pre-surgery rehabilitation may be beneficial not only for knee function and the recovery process, but also to overall health and quality of life for patients. "Pain is typically the primary reason for having a knee replacement. Because of the pain, patients are less active. 'Pre-habilitation' in the form of exercise may improve overall health because it may maintain-or even increase-activity during the period when patients are waiting for their surgery."
What is total knee replacement?
Total knee-replacement surgery involves replacing the damaged knee with an artificial version made of metal and plastic. The bottom end of the thigh bone and the top end of the shin bone are replaced, and often the back of the kneecap are refaced.