Knee Replacement Exercises

Exercise and physical therapy after total knee replacement is associated with early return to activity and decrease in post operative pain and stiffness. Knee replacement surgery is a common surgery and the most successful surgery in medicine.

Knee replacement implants on an average last more than 20 years and more. Exercise and physical therapy forms an important part of post operative rehabilitation.

During the surgery, the arthritic ends of the knee joint are replaced with prosthetic metal alloy and plastic parts. The surgery involves cutting of the tissues and the bone to fix the prosthetic parts. A bone cement is used to fix the prosthetic parts at the ends of the thigh bone, shin bone and the undersurface of the patella.

X-ray showing a total knee replacement.

As the muscles and tissues are separated and cut to perform the surgery, a range of motion exercises started after surgery help prevent stiffness. Regular exercise is recommended for at least 30 minutes, repeated 3-4 times a day along with regular walking.

Immediately following the surgery, the patients are advised to do ankle pumps. Ankle pumps involve pushing the ankle down and up while lying straight on the bed. The calf muscles contract when performing ankle pumps. The contraction of calf muscles not only improves circulation but also prevents serious complications like deep vein thrombosis.

Deep vein thrombosis is the formation of blood clots in the veins of the leg that may travel up to the lungs to cause pulmonary embolism. Deep vein thrombosis may occur in response to a major surgery like knee replacement. Exercise and early ambulation helps to improve the circulation that plays a role in preventing deep vein thrombosis.

While lying straight on the bed, the patients are advised to contract their thigh muscles, the thigh muscles (quadriceps) contract helps to straighten the knee. To aid in exercise, the patients are advised to try to touch the back of their knees to the bed and hold it in the position for some time. The exercise is repeated alternatively on each leg and done multiple times a day.

Intraoperative image showing prosthetic component.

Straight leg raise exercise may be performed while lying straight or in sitting position. While lying straight, the patients are advised to try to move their leg straight up in the air, lifting a couple of inches off the bed. The straight leg is held up in the position till the thigh muscles are fatigued. The exercise is repeated on the other leg and multiple repetitions are done throughout the day.

Straight leg raise when performed in a sitting position, involves raising the leg to straighten the knee and holding it in position. Similar to lying down technique, the exercise is repeated multiple times.

Knee bending exercises may be done while lying on the bed or in a sitting position. While lying down on the bed, the patient is advised to slowly bend their knee with their sole of the foot touching the bed. The patients are advised to bend their knee as far as possible and hold in that position for some time and slowly bring it back. The exercise is repeated with an attempt to bend further each time.

The knee bends may be performed using a rubber band for support. The knee band may similarly be performed unsupported or supported while sitting in a chair. In supported knee bends the other leg is used to aid in bending the knee.

Majority of the patients may be able to walk the same day of the surgery or the day after. The patients are advised to walk using a walker as an ambulatory aid. The patients are advised to first be comfortable standing. Once comfortable, the patients are advised to advance their walker forward and move with their operative leg first.

The patients are advised to keep the operated leg straight and move forward with their heel touching the ground first. The amount of weight bearing will depend upon the type of knee replacement.

Once the patients are comfortable walking and standing for long, the patients may be allowed to use a cane for ambulation. Climbing and descending stairs are an important part of daily activity. The patients are advised to climb the stairs one step at a time.

During climbing the stairs, the non operated knee is placed first, while during descending the stairs, the operated knee is placed first. The use of handrail is recommended at all times during navigating the stairs.

Advanced exercises such as resisted knee bends and straightening exercises are initiated under supervision of a physical therapist. The advanced exercises help in building the muscles around the knee and increasing the range of motion.

Exercise and physical therapy after knee replacement not only helps in the early return to activities but also decreases the pain and swelling associated with the surgery. The improvement in circulation with the exercises help in decreasing the swelling. Stiffness of the knee is a common complication when adequate exercise regime is not followed after surgery.