Content area
Full Text
Abstract-Stiffness following surgery or injury to a joint develops as a progression of four stages: bleeding, edema, granulation tissue, and fibrosis. Continuous passive motion (CPM) properly applied during the first two stages of stiffness acts to pump blood and edema fluid away from the joint and periarticular tissues. This allows maintenance of normal periarticular soft tissue compliance. CPM is thus effective in preventing the development of stiffness if full motion is applied immediately following surgery and continued until swelling that limits the full motion of the joint no longer develops. This concept has been applied successfully to elbow rehabilitation, and explains the controversy surrounding CPM following knee arthroplasty. The application of this concept to clinical practice requires a paradigm shift, resulting in our attention being focused on preventing the initial or delayed accumulation of periarticular interstitial fluids.
Key words: bleeding, continuous passive motion (CPM), edema, fibrosis, granulation tissue, joint stiffness.
INTRODUCTION
Von Riemke, in his presidential address to the Danish Surgical Society in 1926, stated that, "All joint affections...should be moved. Movement should begin on the first day, should be very slow, and as much as possible it should be continuous." Salter, who invented the concept of continuous passive motion, which has come to be known as simply "CPM," derived this concept on the basis of a series of experimental investigations and well thought-out rationale. Salter and Field (1) showed in 1960 that immobilization of a rabbit knee joint under continuous compression, provided by either a compression device or forced position, resulted in pressure necrosis of the cartilage. In 1965, Salter et al. (2) reported deleterious effects of immobilization on the articular cartilage of rabbit knee joints and the resultant lesion that they termed "obliterative degeneration of articular cartilage." Salter (3) believed that "The relative place of rest and of motion is considerably less controversial on the basis of experimental investigation than on the basis of clinical empiricism." He reasoned that because immobilization is obviously unhealthy for joints, and if intermittent movement is healthier for both normal and injured joints, then perhaps continuous motion would be even better. Because of the fatigability of skeletal muscle, and because a patient could not be expected to move his or her own joint constantly, he concluded that...