Healing and Exercise
After knee replacement surgery, one of the most important parts of the recovery process is the healing of the muscles. Even with minimally invasive surgery, there is some damage to the muscles that surround and support the knee. This damage often is magnified because of the weakening of the muscles that occurred before the surgery as the patient avoided putting weight on and using the knee. A recent study, performed at the University of Delaware by Lynn Snyder-Mackler followed the outcomes of patients who had recently had knee replacement surgery and divided them into patients who received progressive strength training as compared to those who just had standard physical therapy at home. This study found that the patients who completed strength training as part of their rehabilitation had significantly stronger quadriceps as well as greater function in their knees (as measured both by the patients and by clinicians) when compared with the patients who received only home physical therapy. This study helped establish the importance of exercising for muscle healing after total knee replacement.
Therapy
Because of the importance of exercise on muscle healing after a total knee replacement, the American Association of Orthopaedic Surgeons recommends beginning physical therapy 48 hours after the surgery has been completed, despite the expected pain and stiffness. This therapy initially involves using a knee brace, which will be left on while the patient is walking and sleeping, though the brace may be removed for portions of the therapy. Many physical therapists recommend a continuous passive motion machine, which will move the knee through a range of motions without requiring any effort on the part of the patient. Many patients will be told to continue their physical therapy using exercises at home. Once the patient returns to normal exercise activities, the surgeon will recommend avoiding running and contact supports and instead suggest activities such as swimming, that will strengthen the knee without running the risk of injuring it.
Home Exercises
Many patients can do strengthening exercises at home to help with muscle healing. These include straightening the leg while keeping the thigh tense, lifting the leg straight in the air, and bending and straightening the knee while a small towel is under the ankle. The American Association of Orthopaedic Surgeons also recommends doing knee-bends while laying down and sitting to help strengthen the knee. The patient can help support the operated knee by placing the foot from his other leg behind or under the knee.
