The effects of polysulphated glycosaminoglycan on the healing of collagenase induced tendinitis

Objective. To examine the effects of polysulphated glycosaminoglycan on ten don healing in a controlled collagenase injury model. Design. The study use d a completely randomized design with four horses assigned to each of two g roups, control and treated. The superficial digital flexor tendons from eac h horse were measured weekly by ultrasound techniques. The differences betw een groups were evaluated using t-statistics and trends summarized by simpl e linear regression. Animals. Eight horses (four Thoroughbreds and four Sta ndardbreds) with normal superficial flexor tendons were divided into two gr oups of four. Group #1 control horses were not treated. Group #2 horses wer e treated with polysulphated glycosaminoglycans. Procedure. All of the hors es had tendinitis induced in the superficial flexor tendon of both forelimb s by the injection of 4000 IU of collagenase. The treated group received 50 0 mg of polysulphated glycosaminoglycan (PSGAG) IM every five days for seve n treatments beginning 24 h after injection of collagenase. The control gro up received saline at the same time periods. Ultrasound examination of each limb was performed on days 1, 3, 5, and 7 post-injection and weekly therea fter for eight weeks. An image analysis system was used to measure the prop ortion of tendon area damaged in mm(2) on the recorded images, and these va lues were plotted over time. The horses were euthanatized at eight weeks an d histological evaluation was performed on longitudinal sections of excised tendons. Results. The size of the tendon core defects created by the colla genase enzyme, represented as the proportion of area damaged, decreased sig nificantly faster in the treatment group (p <0.01). Histologic evaluation o f the core defects confirmed what was seen sonographically. Conclusion. Pol ysulphated glycosaminoglycans had a positive effect on tendon healing in a collagenase induced tendinitis model. Clinical relevance. Polysulphated gly cosaminoglycans may be beneficial in managing clinical cases of tendinitis.