1. Could PEMF aid the mechanism of repair of articular cartilage? In osteoarthritis degeneration and erosion of the articular cartilage is a basic aspect of the pathologic process, but there is abundant evidence for a reversibility to this process. There is proliferation of chondrocytes at the site of the lesions, and the increased synthesis of proteoglycans and collagen occurring in the cartilage at the site at which there is accelerated loss of these matrix components. These phenomena can slow or even reverse the lesions, and there is evidence for such reversibility clinically under certain circumstances (a prime example is the appearance of new cartilage in the hip joint following a surgical procedure known as a Pauwels osteotomy, in which the site of weight bearing stress in the hip joint is shifted.) No present non-surgical therapy has been shown to cause reversal of the lesions, but it is potentially possible. How such a process would affect the pain is not known; however, the ability of the cartilage to absorb compressive stress would be augmented, and therefore the physical stresses on the underlying bone and other joint tissues which have nerve endings, such as the capsule, would be diminished.

During the course of the study of PEMF therapy of osteoarthritis it should become possible to investigate the possibility that this treatment slows progression or causes some reversal of the pathology of the disease. Such studies should give us a better idea of the mechanism of action of this form of therapy.