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 load-displacement 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 non-aperture 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 non-aperture 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 déplacement. 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.
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Acknowledgements
The authors acknowledge the Edmonton Orthopaedic Research Committee for their financial support.
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