Continuous passive motion machine [CPM] has not been shown to improve results. It is not harmful, but certainly not necessary.
The key to regaining range of motion is to use gravity. To regain flexion (bending) we recommend letting the knee hang off the side of the bed and using the opposite leg as a pusher to push the operated foot back. To regain extension (straightening) we recommend putting pillows under the heel while lying down and allowing the leg to come into extension (straight).
Exercises demonstrated are for right knee. Bend using the other leg plus gravity as shown on the left. To work on straightening, elevate the foot on a pillow or towel and suspend the leg using gravity.
It is okay to have some soreness during stretching, but the knee should not be sorer the day after. If that is the case, the stretching has been too aggressive. Aggressive flexion exercises should never be done. The patient should never be put prone (face down) and have their knee bent by the therapist and they should never bend their knee forward against a stair.
The Key is to Make Progress
Physical Therapy with a therapist is helpful but it is most critical that the patient do their bending and straightening exercises every single day on their own. Even if only for a few minutes, the exercises must be done every single day the first two months after surgery, or until adequate range of motion has been restored.
We aim to have a minimum of 90 degrees of bending by six weeks and ideally more. We recommend icing after stretching sessions but not before. We don’t recommend use of heat. It is important to remember that range of motion can continue to improve for many months after surgery. The key is to continue making progress, which can continue for a long time, even if it is slow.
Please feel free to contact us with any questions.