Intrinsic tendon healing. A new experimental model.

A new experimental model was developed to study intrinsic flexor tendon healing in vivo. Segment of flexor tendons from the synovial sheath region of rabbits' forepaw were cut, resutured and placed in a silicone tube, sealed in both ends with a GORE-TEX pericardial patch (pore-size less than 1 micron), fastened with silicone glue. The chamber was left subcutaneously in the back of rabbits for six weeks. At this time the chamber was filled with clear tissue fluid. Histologically and ultrastructurally the tendon demonstrated fibroplasia with cell proliferation and collagen synthesis in spite of the fact that no extrinsic cells could gain entrance into the chamber--a finding supporting the concept of intrinsic healing.