Repair of digital flexor tendon lacerations in the horse, using carbon fiber implants

Flexible medical grade carbon fiber was surgically implanted in tenectomized or lacerated superficial and deep digital flexor tendons of 13 horses (7 clinical cases and 6 experimental), ranging in age from 15 months to 10 years and weighing 300 to 500 kg. The 6 experimental horses were euthanatized at 30-, 45-, 60-, and 90-day intervals for gross and histologic evaluation of the results. Three of the experimental horses served as their own controls. Of the 7 clinically affected horses, 3 were euthanatized because they developed laminitis or the wound failed to heal. The remaining 4 horses in that group were discharged; 3 returned to their previous activities, and 1 was unavailable for follow-up. Carbon fiber produced a structure of approximately the same size and function as a normal tendon. Histologically, the fibroblasts and collagen fibers organized and aligned themselves in the early stages of healing. The implants appeared grossly and histologically to produce a cosmetically acceptable, strong, and functional tendon.