Tendon grafts with preserved muscle demonstrate similar biomechanical properties to tendon grafts stripped of muscular attachments: a biomechanical evaluation in a porcine model

Luis Fernando Zukanovich Funchal,Ari Digiácomo Ocampo Moré,Carlos Rodrigo De Mello Roesler,Diego Costa Astur,Andrew Esteban Jimenez,Moises Cohen,Arthur Paiva Grimaldi,André Luiz Almeida Pizzolatti

doi:10.1186/s40634-021-00375-6

Abstract

Purpose(1) To evaluate the biomechanical properties of a porcine flexor digitorum superficialis tendon graft with preserved muscle fibers and (2) to compare these results with the biomechanical properties of a porcine tendon graft after removal of associated muscle.MethodsEighty-two porcine forelegs were dissected and the flexor digitorum superficialis muscle tendons were harvested. The study comprised of two groups: Group 1 (G1), harvested tendon with preserved muscle tissue; and Group 2 (G2), harvested contralateral tendon with removal of all muscle tissue. Tests in both groups were conducted using an electro-mechanical material testing machine (Instron, model 23-5S, Instron Corp., Canton, MA, USA) with a 500 N force transducer. Yield load, stiffness, and maximum load were evaluated and compared between groups.ResultsThe behavior of the autografts during the tests followed the same stretching, deformation, and failure patterns as those observed in human autografts subjected to axial strain. There were no significant differences in the comparison between groups for ultimate load to failure (p = 0.105), stiffness (p = 0.097), and energy (p = 0.761).ConclusionIn this porcine model biomechanical study, using autograft tendon with preserved muscle showed no statistically significant differences for yield load, stiffness, or maximum load compared to autograft tendon without preserved muscle. The preservation of muscle on the autograft tendon did not compromise the mechanical properties of the autograft.Level of evidenceLevel III Controlled laboratory study

Highlights

Semitendinosus (ST) and gracilis (G) tendons have been increasingly used as grafts for numerous tendon and ligament structures because of their anatomical features, including a straightforward harvesting technique [6, 8, 11, 25, 27]
Material and methods A total of eighty-two porcine forelimbs from two MS60 and F1 breeds were evaluated and their flexor digitorum superficialis muscle tendons were harvested for biomechanical analysis
There were no significant differences in the comparison between groups for yield load (p = 0.105), stiffness (p = 0.097), and maximum load (p = 0.761), as outlined in Figs. 5 and 6

Summary

Introduction

Semitendinosus (ST) and gracilis (G) tendons have been increasingly used as grafts for numerous tendon and ligament structures because of their anatomical features, including a straightforward harvesting technique [6, 8, 11, 25, 27]. These tendons are commonly used for anterior. Autograft tendons are commonly stripped of the adjacent muscular tissue before graft preparation [29] This process inevitably causes a certain degree of trauma to the tendon and, on a cellular level, may compromise graft healing [17]. Funchal et al, described the clinical and histological advantages of preserving the adherent muscle tissue during ACL reconstruction, with improved knee function scores, return to sport, and increased final size of the autograft used [9]

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