Quadriceps tendon allografts as an alternative to Achilles tendon allografts: a biomechanical comparison

Abstract

Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R.

Tendon Biomimetic Electrospun PLGA Fleeces Induce an Early Epithelial-Mesenchymal Transition and Tenogenic Differentiation on Amniotic Epithelial Stem Cells

“…Moreover, the ha-PLGA fleeces, different from the rd-PLGA ones used as control, closely mimic the biomechanical properties of a native tendon, as in fact, especially the stress values were comparable to those of the human tissues (i.e., human Achilles, rotator, and patellar tendons) [2]. In detail, the stress values of the produced ha-PLGA fleeces (26.02 ± 1.75 MPa) closely resembled those published for human Achilles tendons [2,65], human patellar tendons (5-65 MPa) [2,66], human rotator tendons (14-45 MPa), and human Achilles grafts (16 MPa) [2]. These obtained data are in accordance with those published previously and confirm that the mechanical properties depend on the fiber orientation and possess higher mechanical strength when the fibers are aligned, compared to the randomly distributed ones [16,56,67].…”

Tensile properties of a split quadriceps graft for ACL reconstruction

“…The current study calculated creep as the percent difference in graft elongation due to creep, whereas previous studies calculated creep as the difference in graft strain between first and last cycles [24,36]. Thus, direct comparisons cannot be made between studies.…”

“…Full-thickness quadriceps tendon grafts of approximate dimensions of 1 by 10 cm [24,35,36] were prepared with attached bone block by an orthopaedic surgeon to mimic grafts for anatomic doublebundle ACL reconstruction surgery [7,17,19,37]. Each graft was then split in half using a No.…”

Effects of external operating environments on fatigue of heat‐exchanger copper tubes

“…Tensile tests using tensile testing system MTS 810 (MTS Systems Corporation, USA) were performed on 10 specimens at room temperature (25°C), a load speed of 0.1 mm/s, and a gauge length of 100 mm while gradually increasing the load until the occurrence of fractures (Figure ). In the current study, we have measured strain from the change in the grip‐to‐grip length relative to the initial grip‐to‐grip length . The stress‐strain curves obtained were used to measure the tensile strength, yield strength, and elongation of the copper tubes.…”