Osteoarthritis of the Knee in the Rabbit Produced by Immobilization:: Attempts to Achieve a Reproducible Model for Studies on Pathogenesis and Therapy

Abstract

In order to obtain a reproducible experimental model of osteoarthritis a method of immobilizing the rabbit's knee in extension by means of a plastic splint was developed. The right knees of the rabbits were immobilized for periods varying from 4 days to 24 weeks. With the left knees as controls the knees were studied in a variety of ways among these being radiography (126 rabbits), histological sections stained with Alcian Blue (88 rabbits), analysis of 35S-sulphate uptake (22 rabbits) and 35S-autoradiography (6 rabbits). In 27 rabbits the regaining of mobility after immobilization was studied. After 5–6 weeks of immobilization most of the knees showed moderate or severe changes including loss of articular cartilage and osteophyte formation. Immobilization of the rabbit's knee by this method provokes a fairly easily reproducible type of degenerative joint disease showing similarities to advanced osteoarthritis as seen in humans.