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.