Effect of hyaluronic acid on the excursion resistance of tendon graft: A biomechanical in vitro study in a modified human model

Background: Adhesion between the tendon and tendon sheath after flexor tendon graft inhibits restoration of excursion and strength of the grafted tendons, so post-operative finger function is occasionally unsatisfactory. Early setting rehabilitation is one important factor to prevent the adhesion, and another factor may be a lubricant. We considered the possibility of utilizing hyaluronic acid as a lubricant. The goal of this study is to investigate the in vitro effect of hyaluronic acid on tendon excursion resistance against a digital pulley in a modified human model. Methods: The excursion resistance between grafted intrasynovial and extrasynovial tendons and A2 pulley were evaluated, and compared before and after soaking in 10 mg/ml hyaluronic acid. Findings: The resistance increased after extrasynovial tendon graft, and then it decreased after soaking hyaluronic acid solution. Interpretation: The evidence we collected suggests that some style of administration of the hyaluronic acid might reduce the excursion resistance in the tendon-pulley unit, facilitating post-operative rehabilitation and limiting adhesion, after tendon graft and possibly improve the clinical outcome of flexor tendon graft.