Changes in Bone Formation During Immobilization and Development of Experimental Osteoarthritis: A Study using Oxytetracycline in Rabbits

Abstract

The effect of immobilization on bone formation in the knee and hip was studied by means of oxytetracycline. One leg of 11 growing and 13 adult rabbits was immobilized so that the knee was held in extension but the hip was free. In the knee, degenerative changes developed consistently with a severity proportional to the length of the immobilization time. In most of the rabbits given oxytetracycline 1–13 days before they were killed considerably more oxytetracycline was incorporated in the bone in the immobilized knee region and slightly more in the hip region of the same leg than in the corresponding areas of the other leg. This indicates an increased turnover of bone tissue in the immobilized leg compared with the non-immobilized leg.