EFFECT OF MOTION AND TENSION ON INJURED FLEXOR TENDONS IN CHICKENS

This study was undertaken to evaluate the individual effects of motion and tension on the healing response of injured flexor profundus tendo ns in chickens. Partial midsection transverse lacerations of the profu ndus tendons were produced in 53 chickens. Postoperatively, they were assigned randomly to four management groups: both motion and tension; only motion, no tension; no motion, only tension; no motion and no ten sion. Biomechanical results at 4 weeks showed that breaking strength s ignificantly increased with both motion and tension, significantly dec reased with neither, and was intermediate with only motion or only ten sion. Histologic evaluation generally showed the greatest cellular act ivity with both motion and tension, the least with neither, and an int ermediate response with one or the other alone. Collagen fiber stainin g was increased primarily in the tension groups. The finding that both motion and tension enhance the tendon's response to injury encourages the development of active mobilization protocols following tendon rep air.