Bridge tendon graft in no man's land: an experimental study in chickens

OBJECTIVE: To investigate the morphological characteristics of the bridge tendon grafting in no man's land to reconstruct the tendon defect and the effect of passive mobilization on it. METHODS: A 2 cm defect was made in bilateral flexor digitorum profundus tendons of the middle chicken toes, and was then transplanted to the opposite site to serve as a segmental autograft tendon. Postoperatively, passive mobilization of the left and right middle toes began at 5 and 21 d separately. Specimens were studied by light, scanning and transmission electron microscopy at 5, 10, 21 and 35 d. RESULTS: Early repair of the tendon-graft of the left middle toes was made by proliferation and ingrowth of the epitenon cells intermingled with newly-formed collagen fibers. A gliding surface formed at 10 and 21 d. The tendon graft itself played an active role in the repair. In contrast, adhesions obliterated the surface and occupied the space between the tendon graft and surrounding tissues in the right middle toes. CONCLUSIONS: It indicates that the use of the segmental bridge tendon graft in no man's land coupled with early passive motion stimulates an intrisic repair process in both the tendon stump and the autogenous tendon graft and results in a functional healing.