Relative Motion of Tendon Limbs in a Loop Tendon Graft

Abstract

The biomechanical data derived from the standard tensile testing machines may not be able to show the relative motion of the graft limbs. This paper uses a digital stereo image recording system, synchronized with the standard test machine, to determine the relative motion of a looped tendon graft. Bovine°exor tendon was used to create the looped graft and then the graft was passed through a tunnel in a foam block and¯xed with an interference screw. The structure was then mounted in a testing machine. The tendon limbs surfaces were speckled just moments before test, and two cameras synchronized with the test machine were capturing the movements of the speckles. Following a cyclic loading from 50À250 N at 1.0 Hz for 500 cycles, a load-to-failure test was carried out at a rate of 20 mm/min. The load-displacement data and the corresponding images of the graft were used to examine the mechanical properties of the graft structure and the relative motion of the individual graft limbs. There was no signi¯cant di®erence between the mechanical properties of the grafts structure. The average displacement of the grafts structure was 6.95 mm, while the average relative motion between the loop limbs up to the point of the graft failure was 0.3 mm.

Biomechanical Modeling of a Bone Tunnel Enlargement Post ACL Reconstruction

“…By maintaining the four-tailed end of the tendon bundle, a 10 mm diameter interference screw was screwed into the entrance (anterior aspect) of the tunnel between the tendon strands and moved forward until its tip reached the proximal bone-tunnel opening (Fig.1 c). A general biomechanical test, i.e., tensile test as described previously [14][15][16], was performed on the bone and tendon to observe the placement of the graft and screw in the bone tunnel after the mechanical loading. The loop portion of the tendon hanged with the crosshead of the testing machine, and the bone was secured using custom-made grips in the testing machine (Fig.…”

“…After that, if the structure was not failed in previous stages, a load-to-failure test was carried out at a rate of 20 mm/min [14,16]. Failure was characterized either by tendon rupture or when significant slip-up occurs at fixation [17,18].…”

Response to: Comment on “Mechanical assessment of two different methods of tripling hamstring tendons when using suspensory fixation”

“…ACL reconstruction has been widely investigated by many researchers from different aspects of clinical and bioengineering viewpoints [3, 4]. The majority of previous researchers concluded that the tibial fixation is the weakest link in ACL reconstruction [1, 2].…”

Characterisation of soft tissues biomechanical properties using 3D Numerical Approach

“…According to previous researches pertaining to skin, animal skins have been the main samples and focus of study, prepared and tested using the in-vitro procedure. Murine, bovine and rabbit skins were studied to investigate the biomechanical parameters [3][4][5]. On the other hand, several articles have studied and discussed about the investigation of human skin.…”