Passive biomechanical properties of sutured mammalian muscle lacerations

Muscle trauma, such as laceration or transection, is a common occurrence, but repairing delicate tissue poses a clinical challenge. This is at least partially due to the lack of established muscle repair models. The purpose of this study was to compare the biomechanical properties of stitches in transected porcine and bovine muscle bellies. A biomechanical protocol was designed for measuring suture performance in muscle belly lacerations. Twenty simple stitches in porcine and 21 stitches in bovine specimens were tested. Individual stitches were placed in lacerated muscle bellies and tensioned on a biomechanical tester (model 8521S, Instron Corporation, Canton, MA). The mean maximum load for porcine (22.0 N) and bovine (23.9 N) stitches was not significantly different (p = .48). The difference in mean strains at maximum load between porcine (9.7%) and bovine (8.0%) groups was statistically significant (p = .004). Failure mechanisms were similar. One porcine stitch avulsed the muscle transversely, while 19 stitches tore out longitudinally. All 20 stitches tore out in bovine specimens. Sutured muscle was the weakest element in each test. The present study demonstrated that sutured muscles performed similarly for the two mammals regarding the parameters of maximum load and mechanism of failure. Regarding suturing of skeletal muscle lacerations, both mammalian models had similar biomechanical performance for maximum loads and failure mechanisms, while strain data differed. The stitch load magnitudes in this study approximate those required to successfully repair transected muscle. Knowledge introduced by this study fills a gap concerning muscle stitching relevant to clinical care.