The effects of Hylan G-F 20 surface modification on gliding of extrasynovial canine tendon grafts in vitro

Purpose: Studies have shown that a lubricant exogenously applied on extrasynovial tendon surfaces can reduce the gliding resistance after flexor tendon repair; however, the reagents that have been tested are solely for experimental testing and are not available for clinical use. The purpose of this study was to investigate the effect of exogenously applied hylan G-F 20, a U.S. Food and Drug Administration-approved hyaluronic acid for the treatment of osteoarthritis, on extrasynovial tendon gliding resistance in an in vitro canine model. Methods: Twenty-four canine peroneus longus (PL) tendons and proximal pulleys of the ipsilateral paws were treated with 1 of 3 solutions: saline, carbodiimide derivatized hylan G-F 20, or unmodified hylan G-F 20. The gliding resistance of each tendon preparation was then measured over 1000 cycles in a saline bath. Results: After 1,000 cycles, the gliding resistance of the PL tendons treated with unmodified hylan G-F 20 decreased significantly compared with the saline-treated tendons. The gliding resistance of the PL tendons treated with modified hylan G-F 20 increased significantly compared with the saline group. Conclusions: The PL tendons treated with pure hylan G-F 20 showed a positive effect on the gliding resistance. Clinical relevance: The results of this in vitro canine study suggest that exogenously applied hylan G-F 20 improves gliding of the extrasynovial tendon graft. This material may be capable of reducing friction over flexor tendon repair sites and flexor tendon grafts.