Daily repeated traction in developing osteoarthritis. An experimental study in rabbits

The effect of repeated traction on rabbit knee joint was studied during the development of experimental osteoarthritis. The traction (10 N to the immobilized leg) was administered one hour daily during seven weeks of immobilization of the knee and eight weeks of follow-up. The control group consisted of rabbits similarly immobilized and followed but without traction. The degree of osteoarthritis was measured from joint mobility, the evaluation of radiographs and the histological picture. Traction did not statistically significantly increase the mobility range of the knee joint in the treatment group in comparison with that of the control group, and the differences were small between the histological assessments of the two groups. At the end of immobilization the radiographic changes were less marked in the traction group than in the control group, but at the end of the follow-up the difference between the two groups was not as clear. Repeated traction did not, therefore, permanently prevent degenerative changes produced by the immobilization of the rabbit knee.