Caroline Emonts (Aachen), Ricarda Merfort (Aachen), Viktoria Kiaulehn (Aachen), Benedict Bauer (Aachen), Priv.-Doz. Dr.-Ing. Jörg Eschweiler (Aachen), Prof. Dr.-Ing. Thomas Gries (Aachen)
Abstract-Text (inkl. Referenzen und Bildunterschriften)
Introduction
ACL injuries are a common sports injury and ligaments have limited self-healing capabilities. The current treatment methods rely on autologous implants, which are limited by availability and donor site morbidity. Synthetic ACL are rarely used due to their shortcomings in long-term mechanical stability and friction resistance. Tissue engineering offers a new approach by using scaffolds that provide temporary mechanical stability and promote cell ingrowth to regenerate a functional ligament. This study aims to investigate the potential of long-term degradable scaffolds for ACL replacement, utilizing three different braiding technique.
Methods
The scaffolds were manufactured using round, hexagonal and linear braiding with melt-spun PCL monofilaments [1]. Three variations of scaffolds were examined. A uniaxial tensile test with a gauge length of 40 mm comparable to the length of the ACL was conducted. The effect of the braiding technique on the maximum tensile load, elongation, and stiffness was evaluated. A cyclic tensile test with the load of walking (210 N) was performed for 500000 cycles with a frequency of 1,6 Hz.
Results
The braided scaffolds exhibit a tensile strength of 3460-4110 N, surpassing the ACL's tensile strength range of 734-2160 N [2]. The scaffolds are designed to fit within the surgical bone channel diameter of 9 mm. The linear region stiffness of the braids ranges from 186 - 212 N/mm, which is comparable to the native ACL stiffness range of 180-242 N/mm [2]. The laxity of the synthetic ACL caused by creep must not exceed 3-5 mm. [3] The plastic deformation is between 1.0 -1.3 mm for all tested scaffolds. The results show that the requirements for the initial mechanical properties of the ACL as well as the long-term stability can be fulfilled.
References
Bauer et al., Fibers, 10(3):23, 2022 Noyes, F. R. et al., J of Bone and Joint Surgery, 58, 1976 Vieira, A. C., et al.: J of Biomechanics, 2009