The influence of indomethacin on biomechanical and biochemical properties of the plantaris longus tendon in the rabbit.

It has previously been reported that indomethacin inhibits fracture healing and heterotopic bone formation. Stimulated by these reports, we undertook the present investigation to study the influence of indomethacin on biomechanical and biochemical properties of the plantaris longus tendon in the rabbit. Sixty-eight New Zealand White rabbits were used for the experiment. Half of them were treated with indomethacin, 10 mg/kg orally a day, and the other half with placebo. After 4, 8, and 16 weeks of treatment biomechanical and biochemical variables were determined and compared between the two groups. After 16 weeks there was a significant increase in tensile strength in the group treated with indomethacin. There was no certain concomitant change in the total collagen content, the amounts of soluble and insoluble collagen, or the water content. Further investigations concerning the influence of indomethacin on tendon healing are indicated.