Surface Modification of Intrasynovial Flexor Tendon Allograft in a Canine Model In Vitro

INTRODUCTION: The tendon graft still plays an important role to restore hand function if the damaged tendon can not be directly repaired, or if a primary repair fails. Animal studies have shown that intrasynovial tendon autografts result in better functional restoration compared with extrasynovial tendon autografts, but the availability of intrasynovial autograft tendons is limited. Previous work from our laboratory has demonstrated that decreasing the friction of extrasynovial tendon by surface treatment with a carbodiimide derivatized HA (cd-HA) gelatin improves extrasynovial autograft outcomes in an in vivo canine model. Intrasynovial tendon allograft would be another possibility to treat such injuries, but it is not known if a common allograft preparation process, which involves freeze thaw cycling with lyophilization and rehydration to reduce immunogenicity, adversely affects the tendon allograft gliding ability, or whether tendon surface modification cd-HA gelatin has the same beneficial effects on an allograft that it does on an autograft. The purpose of this study was to investigate the effects of cdHA gelatin treatment of a tendon allograft on tendon gliding in a canine intrasynovial tendon allograft model in vitro. We hypothesized that the allograft preparation process would adversely affect tendon gliding, and that cd-HA gelatin surface modification would restore normal tendon gliding ability to the allograft tendons.