MAINTENANCE OF THE GLIDING SURFACE OF TENDON AUTOGRAFTS IN DOGS

To determine whether there are differences in the extent to which the superficial cellular layers remain viable and contribute to the healin g process, extra- and intrasynovial hindlimb donor tendons of 12 dogs (24 tendons) were labeled with 3H-thymidine in vitro and transferred t o the medial and lateral toes of the forepaw. After transplantation, t he distribution and amounts of remaining labeled cells within the heal ing tendon grafts were determined at 1 and 3 weeks after surgery by sc intillation countings and autoradiographic examinations.The two types of tendon grafts showed different turnover rates for the elimination o f labeled DNA. At 1 week, 25 percent of labeled DNA remained in the ex trasynovial grafts and 65 percent in the intrasynovial grafts, The two types of tendon grafts also showed different healing responses histol ogically. Autradiographic examinations showed that the majority of lab eled cells were located in the periphery of the control tendons and th at the numbers of labeled cells within the newly proliferated superfic ial areas of both types of tendon grafts decreased over time. These fi ndings indicate that intrasynovial flexor tendons may possess improved prerequisites for superficial cellular survival and tendon gliding fo llowing autogenous tendon grafting.