Muscle-Secreted Factors Improve Anterior Cruciate Ligament Graft Healing: An In Vitro and In Vivo Analysis

2018 ◽  
Vol 24 (3-4) ◽  
pp. 322-334 ◽  
Author(s):  
Corina Adriana Ghebes ◽  
Nathalie Groen ◽  
Yau Chuk Cheuk ◽  
Sai Chuen Fu ◽  
Hugo Machado Fernandes ◽  
...  
2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Conrad K. Smith ◽  
M. L. Hull ◽  
S. M. Howell

A millimeter-for-millimeter relation between an increase in length of an anterior cruciate ligament graft construct and an increase in anterior laxity has been demonstrated in multiple in vitro studies. Based on this relation, a 3 mm increase in length of the graft construct following surgery could manifest as a 3 mm increase in anterior laxity in vivo, which is considered clinically unstable. Hence, the two primary objectives were to determine whether the millimeter-for-millimeter relation exists in vivo for slippage-resistant fixation of a soft-tissue graft and, if it does not exist, then to what extent the increase in stiffness caused by biologic healing of the graft to the bone tunnel offsets the potential increase in anterior laxity resulting from lengthening at the sites of fixation. Sixteen subjects were treated with a fresh-frozen, nonirradiated, nonchemically processed tibialis allograft. Tantalum markers were injected into the graft, fixation devices, and bones. On the day of surgery and at 1, 2, 3, and 4 months, Roentgen stereophotogrammetric analysis was used to compute anterior laxity at 150 N of anterior force and the total slippage from both sites of fixation. A simple linear regression was performed to determine whether the millimeter-for-millimeter relation existed and a springs-in-series model of the graft construct was used to determine the extent to which the increase in stiffness caused by biological healing of the graft to the bone tunnel offset the increase in anterior laxity resulting from lengthening at the sites of fixation. There was no correlation between lengthening at the sites of fixation and the increase in anterior laxity at 1 month (R2=0.0, slope=0.2). Also, the increase in stiffness of the graft construct caused by biologic healing of the graft to the bone tunnel offset 0.7 mm of the 1.5 mm potential increase in anterior laxity resulting from lengthening at the sites of fixation. This relatively large offset of nearly 50% occurred because lengthening at the sites of fixation was small.


2001 ◽  
Vol 29 (2) ◽  
pp. 161-166 ◽  
Author(s):  
Bruce D. Beynnon ◽  
Benjamin S. Uh ◽  
Robert J. Johnson ◽  
Braden C. Fleming ◽  
Per A. Renström ◽  
...  

2000 ◽  
Vol 122 (6) ◽  
pp. 600-603 ◽  
Author(s):  
Isaac Zacharias ◽  
M. L. Hull ◽  
Stephen M. Howell

To determine which exercises do not overload the graft-fixation complex during intensive rehabilitation from reconstructive surgery of the anterior cruciate ligament (ACL), it would be useful to measure ACL graft loads during rehabilitative activities in vivo in humans. A previous paper by Ventura et al. (1998) reported on the design of an implantable transducer integrated into a femoral fixation device and demonstrated that the transducer could be calibrated to measure graft loads to better than 10 percent full-scale error in cadaveric knees. By measuring both the static and fatigue strengths of the transducer, the purpose of the present study was to determine whether the transducer could be safely implanted in humans without risk of structural failure. Eight devices were loaded to failure statically. Additionally, seven devices were tested using the up-and-down method to estimate the median fatigue strength at a life of 225,000 cycles. The average ultimate strength was 1856±74 N and the median fatigue strength was 441 N at a life of 225,000 cycles. The maximum graft load during normal daily activities is estimated to be 500 N and the 225,000 cycle life corresponds to that of the average healthy individual during a 12-week period. Considering that patients who have had an ACL reconstruction are less ambulatory than normal immediately following surgery and that biologic incorporation of the graft should be well developed by 12 weeks thus decreasing the load transmitted to the fixation device, the FDT can be safely implanted in humans without undue risk of structural failure. [S0148-0731(00)00606-3]


Author(s):  
Ali Hosseini ◽  
Thomas J. Gill ◽  
Guoan Li

The knowledge of in-vivo ACL forces is instrumental for understanding ACL injury mechanisms and for improving surgical ACL reconstruction techniques. Several in-vitro investigations have measured ACL forces in response to various loads applied to the knee. However, in-vivo ACL forces in response to controlled loading are still unknown. The objective of this study was to estimate the force of healthy ACL as well as the possible upper bound of ACL forces under an increasing axial tibial loading in living subjects using a non-invasive method.


2015 ◽  
Vol 15 (01) ◽  
pp. 1550006 ◽  
Author(s):  
ZHENG LI ◽  
JIANKANG HE ◽  
XIANG LI ◽  
WEIGUO BIAN ◽  
WENYOU ZHANG ◽  
...  

Silk was widely investigated as a promising scaffold material in ligament tissue engineering. Although a variety of silk scaffolds were developed for the regeneration of anterior cruciate ligament (ACL) in vitro and in vivo, more investigations should be performed in large animals to translate these findings into clinical applications. The aim of this study is to evaluate the feasibility of using silk-based ACL scaffolds to regenerate damaged ACLs in porcine model. The microstructural organization, tissue regeneration as well as ligament-bone interface of silk implants were evaluated with scanning electron microscopy, micro-computerized tomography, histological and immunohistochemical staining at three and six months postoperatively. The results demonstrated that silk fibers in the ACL scaffolds organized in parallel similar with collagen fibers in native ligaments, which facilitated and guided the penetration of newly regenerated tissue into the pores among silk fibers. Collagen production especially collagen I in silk implants significantly increased from three to six months, and was gradually close to the level of native ligaments. At implant-bone interface, indirect ligament-bone insertion was observed at three months and substantial Sharpey's fibers formed at six months. The results indicated that the silk-based ACL scaffold provides a promising tissue engineering approach for ACL regeneration.


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