Continuous passive motion (CPM) devices are used as a supplementary tool in rehabilitation settings. They are utilized typically following a soft tissue surgical procedure or trauma. CPM promotes the movement of synovial fluid to allow for better diffusion of nutrients into damaged cartilage, and diffusion of metabolic waste products other materials out (blood, toxins). Another mechanism is the prevention of fibrous scar tissue formation in the joint, which tends to decrease the range of motion. The goals continuous passive motion are:

  • Control pain (post-operative and non-operative)
  • Reduce inflammation and swelling
  • Provide passive motion in a specific plane of movement thereby increasing range of motion
  • Protect healing tissue and surgical repair site
  • Prevent arthrofibrosis and scar tissue formation

CPM is carried out by an electrically controlled medical device, which constantly moves the joint through a controlled range of motion; the exact range is dependent upon the joint, but in most cases the range of motion is increased over time. CPM is used following various types of reconstructive joint surgery such as knee replacement, knee arthroscopy and ACL reconstruction.