AUTOGENOUS FLEXOR TENDON GRAFTS - BIOLOGIC MECHANISMS FOR INCORPORATION

To examine the hypothesis that different types of dense regular connec tive tissue may have different repair mechanisms within the synovial s pace, intrasynovial and extrasynovial autogenous donor flexor tendon g rafts were placed within the synovial sheaths of the medial and latera l forepaw digits of dogs, Histologic, ultrastructural, biochemical, an d biomechanical analyses were done between 10 days and 6 weeks after t endon grafting, Intrasynovial tendon grafts remained viable when trans ferred to the synovial space and appeared to heal through an intrinsic process with preservation of the gliding surface and improved functio nal characteristics. Extrasynovial tendon grafts functioned as a scaff olding for the early ingrowth of new vessels and cells, Early cellular necrosis consistently was followed by the ingrowth of fibrovascular a dhesions from the periphery, The formation of dense peripheral adhesio ns, obliterating the gliding surface of the tendon, led to diminished tendon excursion and proximal interphalangeal joint rotation.