Clinical application of basic research on continuous passive motion for disorders and injuries of synovial joints: A preliminary report of a feasibility study

Since 1970, when the concept of continuous passive motion (CPM) was originated by one of the authors (R.B.S.), he and a succession of his research fellows have investigated its biological effects on the healing and regeneration of articular tissues in a wide variety of experimental models in rabbits. From this basic research he concluded that CPM is well tolerated, seems to be painless, stimulates the healing and regeneration of articular tissues, prevents joint stiffness, and permits the normal healing of arthrotomy incisions. Beginning in 1975, one of the authors (H.W.H.), and in 1978, the remaining authors, (from two additional Canadian cities) applied the knowledge from the basic research on CPM to the orthopaedic care of human patients. The CPM devices for humans (CPM Mobilimbs), which have been designed in collaboration with University of Toronto engineers, include, to date, devices for the ankle-knee-hip, the elbow, and the finger. Indications for CPM in patients have been the immediate postoperative management following such operative procedures as open reduction and internal fixation of fractures, arthrotomy and arthrolysis for post-traumatic arthritis, synovectomy, surgical drainage for septic arthritis, release of extraarticular contractures, metaphyseal osteotomies, total joint replacement, and ligamentous reconstruction. The case reports of nine selected patients are presented as examples of the clinical application of CPM. These patients have been relatively free of pain, have maintained the increased motion gained at operation, and have accepted the application of CPM well. There have been no complications of CPM; the operative wounds have healed well and the period of hospitalization has not been prolonged. The authors believe that the clinical application of CPM is feasible and that the clinical and radiographic results of CPM in these patients are encouraging. Long-term, prospective clinical investigations (including control patients in whom CPM is not used) will be required to assess the efficacy of CPM in relation to the various stated indications.