INTRAARTICULAR INJECTION OF KETOROLAC IN THE RAT KNEE-JOINT - EFFECT ON ARTICULAR-CARTILAGE AND SYNOVIUM

We have investigated the effects of intraarticular (i.a.) administrati on of ketorolac in the rat knee joint. Thirty Sprague-Dawley rats were given 0.25 ml of a standard preparation of ketorolac trometamol (10 m g ml(-1)) by injection into the right knee joint and 0.25 ml of 0.9% p hysiological saline solution by injection into the left knee as a cont rol, Ten rats were killed at 24 h, 10 at 48 h and 10 at 5 days after i njection. The joints were prepared and sectioned for histological exam ination. There was significantly more inflammation in those knees that had received i.a. ketorolac at all times of examination, with the mos t severe changes occurring 5 days after injection. A further group of 10 rats were given 0.25 mi of 10% w/v ethanol in physiological saline (similar to the vehicle for parenteral ketorolac) injected into the kn ee joint, with a 0.9% saline control injected in the other knee. These rats were then killed at 5 days (as this was the time interval after which we found the maximum inflammatory response in the earlier phase of our study). The joints were prepared and examined histologically. W e feel that the absence of inflammatory changes in these joints make i t unlikely that ethanol was responsible for the inflammation produced by ketorolac injection.