The influence of a cyclooxygenase-1 inhibitor on injured and uninjured ligaments in the rat.

Abstract

Results of previous studies have shown that piroxicam, a cyclooxygenase-1-2 inhibitor, improves the strength of healing ligaments, whereas celecoxib, a cyclooxygenase-2 inhibitor, impairs ligament healing. The selective cyclooxygenase-1 inhibitor, SC-560, will improve the strength of ligament healing in an in vivo rat model. Controlled laboratory study. Eighty male Sprague-Dawley rats underwent surgical transection of their medial collateral ligament. Postoperatively, 20 rats were given SC-560 at a low dose and 20 at a high dose for the first 6 days of recovery; the other 40 received a normal diet. The animals were sacrificed 14 days later, and both the injured and uninjured ligaments were mechanically tested to failure in tension. No significant differences in the strength of injured ligaments were found between drug and placebo treatment. However, the contralateral uninjured ligaments in the SC-560-treated groups failed at 27% higher energy and 22% higher load. This cyclooxygenase-1 inhibitor did not improve the strength of ligament healing but did significantly improve the strength of the contralateral uninjured ligament. A pure cyclooxygenase-1 inhibitor is probably not indicated as a positive influence on ligament healing but might provide benefits in ligament injury prevention.