Animal models: a means to study the pathogenesis of osteoarthritis

A number of animal models have been developed to investigate the pathogenesis of osteoarthritis. In general, rabbits, guinea pigs, and dogs have been the animals of choice, although rats, mice, and birds have also been used. The techniques used to induce disease development include: destabilization of a knee joint either by extra- or intraarticular surgical manipulation; immobilization of the knee joint to alter load impact and distribution; or introduction of a foreign substance into the joint space. The success of a particular animal model rests in the ability to parallel, on a temporal basis, the biological changes which characterize osteoarthritic development as seen in the human population. Macroscopic, microscopic, and biochemical evaluations then permit the detailing of the steps which lead to cartilage erosion. In this manner, link proteins have been found to be deficient in osteoarthritic guinea pig cartilage.