What is the main objective of using continuous passive motion (CPM) following a total knee replacement?

The main objective of using continuous passive motion (CPM) following a total knee replacement is to promote passive knee flexion. CPM devices provide controlled movement of the knee through a predefined range of motion without requiring active effort from the patient. The primary goal is to prevent joint stiffness, promote the healing of soft tissues, and improve circulation in the area surrounding the knee joint.

By utilizing CPM, the therapeutic movement helps to maintain the elasticity of the joint structures, which is crucial after surgery when there is a risk of scar tissue formation. This passive movement facilitates the gradual increase of joint range of motion, particularly focusing on knee flexion, which is essential for functional mobility post-surgery. The hope is to restore normal knee mechanics and prevent complications associated with immobility, making it an important modality in postoperative rehabilitation.

Active knee motions, such as extension or flexion, rely on patient effort and are not the primary aim of CPM therapy, which operates primarily to encourage passive movement.