In a previous communication1 the pathologic changes which followed the production of mild sprain in the knee joint of the rabbit were reported. Since that time, other similar experiments have been performed which are of greater interest, particularly since the results suggest the pathologic basis for the clinical condition termed chronic traumatic arthritis. As a foundation for the discussion, a résumé of the results in the most recent group of experiments together with those reported2 previously is given.
METHOD
After varying amounts of manual force were applied to the knee and ankle joints of ten rabbits, a method was developed for the production of mild and severe forms of sprain without roentgenographic evidence of fracture.In this manner, mild sprains were produced in twelve rabbits (group 1) and severe sprains in eleven (group 2). Roentgenograms of all sprained joints were taken immediately thereafter, and no evidence of injury