Continuous Passive Motion

by Mark Reep, A.T.C.
National Sales Manager, Danniger Medical

Continuous Passive Motion (CPM) is the term coined by Dr. Robert B. Salter, Professor of Orthopedic Surgery at the Hospital for Sick Children in Toronto, to describe the treatment protocol of applying slow, rhythmic and continuous movement to joints immediately following joint injury or surgery. Dr. Salter reasoned that, since intermittent motion was better for joints than total immobilization, continuous motion should be even better. Furthermore, given the fatigability of skeletal muscle, it was clear that this motion must be passively, in this case by a machine, the patient is not causing an active muscle contraction.

Dr. Salter and the ever-growing number of supporters of CPM have demonstrated clinically that CPM, rather than immobilization, is the preferred treatment for joint injuries. Immobilization has been shown to inhibit the circulation of synovial fluid-hence starving the joint cartilage of nutrients-and promote the development of adhesions and scar tissue. CPM, on the other hand, has been shown to nurture and regenerate cartilage while maintaining joint nutrition, lubrication and successful growth of new cartilage. CPM also helps to maintain a good range of motion in the affected joint, thus reducing the length of time required for rehabilitation.

Since Dr. SalterÕs pioneering beginnings the concept of CPM has mushroomed to include even broader indications. It is becoming the standard treatment protocol following joint arthroplasty, many ligament injuries and some arthritic conditions.

As Dr. Salter phrased it "Joints were meant to move" and it is movement, particularly after trauma, which is vital to the maintenance of healthy joint function.

Indications for CPM in patients have been the immediate postoperative management following such operative procedures as open reduction and internal fixation of fractures, anthrolysis, post traumatic arthritis, synovectomy, surgical drainage for septic arthritis, methaphyseal osteotomies, total joint replacements, ligamentous reconstruction, prevention of intra-articular adhesions, release of extra-articular contractures, pain reduction, edema reduction, burn injuries, and maintenance of range motion.

The choice of rest versus motion has always presented a dilemma in the management of musculoskeletal injury and disease. Physical therapists strive to shorten recovery time and enhance the healing process following athletic injuries. They recognize the importance of instituting joint motion as soon as possible, within the safe limits of tissue healing. It should be noted, however, that CPM is not a "cure all" nor intended to replace the therapist, but is to be used in conjunction with physical therapy and as an adjunct to other treatment protocols. CPM is a good addendum to rehab and can make the therapistÕs job easier. Patients still need to work on strength, coordination, and returning to sports/work specific training.

Helping to recover (early) full range of motion is perhaps CPMÕs biggest benefit. It definitely can cut down on the frequency with which patients need to go to rehab just to work on range of motion. With shorter hospital stays and most procedures occurring on an outpatient basis, the majority of CPM usage is in the home. CPM used at home can help maintain range of motion and expedite recovery and because some patients are to losing range, or wonÕt be able to maintain between physical therapy sessions CPM can help the maintenance of progress, so at least when they return for therapy, they wonÕt have to start from square one. CPM also has psychological value for the patient. ItÕs a boost for the patient to wake up and see their knee moving and functioning as opposed to just lying there or being immobilized.

Not all CPM devices are alike; newer models are constantly being manufactured making some older models obsolete. Choosing a provider who will help you determine which device will best suit your patientsÕ needs is important. Some devices are for monthly rental, while others are for purchase. Rentals are on a daily basis and costs vary depending on several such as the type depending on the indication and patient progress. With healthcare management shifting from the clinic to the home, CPM is one way to help reduce cost while at the same time speed up patient recovery.

It is clear that CPM can help keep healthcare costs to a minimum if all healthcare professionals are committed to restoring functional mobility in the most effective and time efficient manner. CPM is a cost-effective form of treatment, because it accelerates recovery and shortens time, hence, helping to reduce overall costs.