Stiffness characteristics of hamstring tendon graft fixation methods at the femoral site

Abstract

In ACL reconstruction, stiffness and strength of a tendon graft complex are important features for knee stability and rehabilitation. The fixation between tendon and bone is known to be one of the weakest components of the graft complex. We examined the tensile loaddisplacement characteristics of looped semitendinosus tendons in a porcine femoral tunnel. Two groups of six cadaveric semitendinosus tendons and porcine femurs were tested, secured with either an aperture or nonaperture fixation method. Constructs were tested at 1 mm/s until failure in a materials testing machine, which allowed force and displacement data to be recorded. The nonaperture fixation group was significantly less stiff for the first 4 mm of displacement and had significantly higher ultimate failure loads. Provided that adequate ultimate strength can be achieved, stiffness properties of a tendon graft will be improved by using aperture fixation in femoral-site ACL reconstruction.Résumé Dans la reconstruction du LCA la rigidité et la résistance du complexe greffe-tendon sont des éléments importants pour la stabilité du genou et la récupération fonctionnelle. La fixation entre le tendon et l'os est connue pour être un des maillons faibles de l'ensemble. Nous avons examiné les caractéristiques de l'élasticité sous traction de tendons du demi-tendineux insérés en boucle dans un tunnel fémoral porcin. Deux groupes de six tendons cadavériques ont été testés, amarrés par une fixation avec ou sans ouverture. Les constructions ont été testées à 1 mm/s jusqu'à la rupture avec une machine á traction qui permet d'enregistrer la force et le déplace-ment. Le groupe avec la fixation sans ouverture était significativement moins rigide pour les premiers 4 mm de déplacement et avait une charge de rupture nettement plus haute. A condition que la tension de rupture puisse être atteinte, les propriétés de rigidité d'une greffe tendineuse seront améliorées en utilisant la fixation avec ouverture au niveau du site fémoral dans la reconstruction du LCA.

Application of Tendon-Derived Stem Cell Sheet for the Promotion of Graft Healing in Anterior Cruciate Ligament Reconstruction

“…The stiffness of the healing complex was calculated from the linear portion of the load-displacement curve. 1 There were 9 samples at each time point in each treatment group except the control group at week 6 (n = 10). However, some samples (n = 3) were torn during preparation.…”

Comparative biomechanical study of the Ligament Plate® and other fixation devices in ACL reconstruction

“…In studies with porcine bones, Nurmi et al [20] reported that the trabecular bone density of the porcine tibia was significantly higher than that of humans as assessed by peripheral quantitative computed tomography (CT) scan. The bone density of the porcine tibia was 323±41 mg/cm 3 , and the bone density of the human tibia was 177±32 mg/cm 3 . Chang et al [7] reported that on dual-energy X-ray absorptiometry, the bone density of the porcine tibia was on average 1.20 g/cm 2 (0.92-1.30 g/cm 2 ) and was identical to that of a young human.…”

“…3 The Ligament Plate® (Solco Biomedical, Seoul, Korea) Fig. 2 The implants are from left to right: EndoButton®, TransFix®, BioScrew®, and Ligament Plate® ful early rehabilitation, fixation strength of the graft is the most important factor [3,6,18].…”

Upregulation of Runt related transcription factor 1 (RUNX1) contributes to tendon–bone healing after anterior cruciate ligament reconstruction using bone mesenchymal stem cells

“…After cyclic preconditioning at the maximum displacement of 0.5 mm, the construct was loaded at a displacement rate of 20 mm/min. The load to failure was recorded, and the stiffness of the femur-ACL graft-tibia complex was calculated from the liner portion of the load–displacement curve [ 22 ].…”