Augmentation of Tendon Healing With Butyric Acid–Impregnated Sutures

Abstract

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.

In Vivo Measures of Shear Wave Speed as a Predictor of Tendon Elasticity and Strength

“…Importantly, our mechanical measures are similar to those reported in the literature. We found a mean elastic modulus of 250 MPa and mean ultimate stress of 34 MPa, which are within the 20-350 MPa (Leek et al 2012, Kahn et al 2013; Nagasawa et al 2008; Ni et al 2012; Reddy et al 1999; Reddy 2004; Revel et al 2003) and 8-40 MPa (Leek et al 2002; Nagasawa et al 2008; Ni et al 2012; Reddy et al 1999; Reddy 2004) ranges reported for the elastic modulus and ultimate stress, respectively, of healthy rabbit Achilles tendons.…”

The role of animal models in tendon research

“…For example, impregnating a suture with Butyric acid has shown improved biomechanical and histological properties in a rabbit model, 79 while coating a suture with mesenchymal stem cells appears to improve repair strength in the period when a repair is typically the weakest (7 to 10 days). 80 Demonstrating the importance of suture technique, a bovine model showed that the triple-strand technique provided greater mean peak load to failure, and greater resistance to gapping when compared with Dresden, Krackow, and modified oblique Dresden techniques (Fig.…”

Coated Sutures

“…7,16,[18][19][20][21][22] The aim of these studies was to locally deliver different growth factors such as basic fibroblast growth factor (bFGF), 20 vascular endothelial growth factor (VEGF), 8 recombinant human platelet-derived growth factor-BB (rhPDGF-BB), 21 bone morphogenetic protein (BMP)-12, or recombinant human growth and differentiation factor-5 (rhGDF-5). 16 Furthermore, sutures coated with mesenchymal stem cells (MSC) 23 or pluripotential embryonic cells 24 were developed in an attempt to integrate cells with a high capacity for proliferation and differentiation into the surgical site to promote healing.…”

“…Four hours before repair, the precoated Vicryl sutures were incubated in BMP-12 to begin absorption of the calcium phosphate surface in accordance with previously reported protein-release studies. 10,19,22,29 The authors compared the effects of the coated sutures (0, 0.15, 1.5, or 3.0 mg) to standard delivery methods such as a BMP-12-loaded collagen sponge (0 or 1.5 mg) or direct injection (0 or 1.5 mg). The authors transected rat Achilles tendons and performed the repairs with one of the previously mentioned biological augmentations.…”