Regulation of metabolism of the chondrocytes in articular cartilage--an hypothesis.

Over a number of years, researchers in many laboratories have studied the changes occurring in an osteoarthritic joint. Most of these studies involved the biomechanical properties of the joint, biochemistry and physiology of cartilage as a whole tissue or at the cellular level. As the involvement of cartilage in the early stages of osteoarthritis is of focal nature, the results of these various studies have been conflicting. Until recently, the chondrocytes were not assigned a major role in the degradation of cartilage matrix. Instead, the matrix-destruction was believed to occur by mechanical attrition. In this paper we discuss the changes occurring in the osteoarthritic joint and provide an hypothesis for understanding the interactions between inflammatory cells and the chondrocytes, leading to an altered metabolism of chondrocytes and loss of cartilage structure.