Functional return of tendon graft protected entirely by pseudosheath--experimental study.

Sixty-three white Leghorn chickens were used in a two-stage tendon grafting into the deep flexor of the third toe. In the first stage, a 4- or 8-week-old pseudosheath was created around the Silastic rod. In the second stage, the grafting was carried out: in 33 birds the new sheath covered the entire tendon graft and its junctions; in 30 controls, only the main portion of the graft was covered by pseudosheath. Following 6 weeks of immobilization, the toe was left free for 8 weeks and active flexion was registered once a week at perching. The covered junctions were found to be of high anatomical quality; they were, on an average, stronger, and flexion return was significantly greater (in 8-week-old pseudosheath) when compared with noncovered control grafts.