Results of a Study Comparing Mechanical Properties of Hand Flexors of Preserved and Fresh Cadavers

Abstract

Introduction: Flexor apparatus of the hand is mechanically strongest and most durable fibrous part of the hand. It can be used as a basic reference tissue to determine the strength of other fibrous structures of the hand. The aim of the study was to determine the mechanical resistance of flexors to each other and to compare the mechanical properties of tendons from preserved and fresh cadavers. Measured values can validate use of more accessible preserved cadavers in future studies determining mechanical properties of other fibrous structures of the hand. Materials and Methods: During anatomical dissection 45 flexors were taken from fresh cadavers and 40 tendons from preserved cadavers. Tendon diameters were measured at both ends and at midpoint. Strength test was performed on a tearing machine in biomechanics laboratory. Results: We evaluated 40 flexors from preserved cadavers, with mean strength of 44.27 MPa (maximum 94.6 MPa, minimum 18.7 MPa) and 45 flexors from fresh cadavers with mean strength 50.59 MPa (maximum 113.3 MPa, minimum 24.7 MPa). In comparsion the strongest tendon is the superficial flexor of the 5th finger (cross section of 0.98 to 4 mm2, mean strength 69.2). The weakest tendon is the superficial flexor of the 3rd finger (cross section of 7.0 to 15.3 mm2, mean strength 32.4 MPa). Conclusion: The results show wide range of strength of flexors from preserved and fresh cadavers. Mean values that close shows, that more accessible preserved cadavers can be used for future testing. The results have a practical impact in determining the minimum tendon diameter necessary for its function in a given muscle, which can safely withstand the force of its tension and they will also serve to compare the mechanical properties of contracting bands in Dupuytren’s contracture with a possible practical impact on the treatment of this disease.