Augmentation of tendon healing with butyric acid-impregnated sutures: biomechanical evaluation in a rabbit model.

BACKGROUND

Butyric acid (BA) has been shown to be angiogenic and to enhance transcriptional activity in tissue. These properties of BA have the potential to augment biological healing of a repaired tendon.

PURPOSE

To evaluate this possibility both biomechanically and histologically in an animal tendon repair model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A rabbit Achilles tendon healing model was used to evaluate the biomechanical strength and histological properties at 6 and 12 weeks after repair. Unilateral tendon defects were created in the middle bundle of the Achilles tendon of each rabbit, which were repaired equivalently with either Ultrabraid BA-impregnated sutures or control Ultrabraid sutures.

RESULTS

After 6 weeks, BA-impregnated suture repairs had a significantly increased (P < .0001) Young's modulus and ultimate tensile strength relative to the control suture repairs. At 12 weeks, no statistical difference was observed between these measures. The histological data at 6 weeks demonstrated significantly increased (P < .005) vessel density within 0.25 mm of the repair suture in the BA-impregnated group. There was also an associated 42% increase in the local number of myofibroblasts in the BA samples relative to the controls at this time. By 12 weeks, these differences were not observed.

CONCLUSION

Tendons repaired with BA-impregnated sutures demonstrated improved biomechanical properties at 6 weeks relative to control sutures, suggesting a neoangiogenic mechanism of enhanced healing through an increased myofibroblast presence.

CLINICAL RELEVANCE

These findings demonstrate that a relatively simple alteration of suture material may augment early tendon healing to create a stronger repair construct during this time.