The Effect of Surface Treatment Using Hyaluronic Acid and Lubricin on the Gliding Resistance of Human Extrasynovial Tendons In Vitro

Purpose: To investigate the effects of tendon surface treatment using hyaluronic acid (HA) and lubricin on the gliding resistance of human extrasynovial palmaris longus (PL) tendon in vitro. Methods: Thirty-two fresh-frozen cadaver human fingers and 16 ipsilateral PL tendons were used. Each PL tendon was divided into 2 pieces, which were randomly assigned into 4 experimental groups. After the gliding resistance of the normal PL tendon segments were measured, the tendons were treated with either saline, carbodiimide derivatized (cd) gelatin and HA (cd-HA gelatin), cd gelatin with lubricin added (cd gelatin plus lubricin), or cd-HA gelatin plus lubricin. After treatment, tendon gliding resistance was measured during up to 1000 cycles of simulated flexion and extension motion. Results: The gliding resistance of the PL tendons in the cd-HA gelatin, cd gelatin plus lubricin, and cd-HA gelatin plus lubricin groups was significantly lower than that of the saline-treated control after 1000 cycles. The gliding resistance in these treatment groups decreased within the first 50 cycles and then increased at a much more gradual rate over the 1000 cycles, with the cd-HA gelatin plus lubricin group being most stable. Conclusions: The results suggest that tendon surface treatment using HA and lubricin can improve the gliding of human PL tendon in vitro. If validated in vivo, tendon surface treatment has the potential to improve the gliding ability of tendon grafts clinically.