scholarly journals Biological enhancement of graft-tunnel healing in anterior cruciate ligament reconstruction

Joints ◽  
2016 ◽  
Vol 04 (03) ◽  
pp. 174-182
Author(s):  
Maristella Saccomanno ◽  
Luigi Capasso ◽  
Luca Fresta ◽  
Giuseppe Milano

The sites where graft healing occurs within the bone tunnel and where the intra-articular ligamentization process takes place are the two most important sites of biological incorporation after anterior cruciate ligament (ACL) reconstruction, since they help to determine the mechanical behavior of the femur-ACL graft-tibia complex. Graft-tunnel healing is a complex process influenced by several factors, such as type of graft, preservation of remnants, bone quality, tunnel length and placement, fixation techniques and mechanical stress. in recent years, numerous experimental and clinical studies have been carried out to evaluate potential strategies designed to enhance and optimize the biological environment of the graft-tunnel interface.Modulation of inflammation, tissue engineering and gene transfer techniques have been applied in order to obtain a direct-type fibrocartilaginous insertion of the ACL graft, similar to that of native ligament, and to accelerate the healing process of tendon grafts within the bone tunnel. Although animal studies have given encouraging results, clinical studies are lacking and their results do not really support the use of the various strategies in clinical practice. Further investigations are therefore needed to optimize delivery techniques, therapeutic concentrations, maintenance of therapeutic effects over time, and to reduce the risk of undesirable effects in clinical practice.

2019 ◽  
Vol 5 (1) ◽  
pp. 505-507
Author(s):  
Mira Dreier ◽  
Samuel Bachmayer ◽  
Christian Baumgartner ◽  
Jörg Schröttner

AbstractAlong with increasing enthusiasm for sports comes an increase of sport related injuries. One of the most common injuries in the human knee is the tear of the anterior cruciate ligament (ACL). The selection of a graft fixation device is an important factor that determines the outcome of an anterior cruciate ligament reconstruction. Before the healing process is completed, the graft is dependent on tibial and femoral fixation devices to maintain normal ACL graft tension. Among various devices, the use of an adjustable loop suspensory fixation device (ALD) in soft-tissue graft reconstruction attracts current interest. An advantage of the ALD is the ability to draw the graft to the depth of the bone tunnel to achieve adequate graft tension while minimizing the empty space in the tunnel. In this study a comprehensive controlled laboratory investigation is performed to examine the biomechanical properties of commonly used cortical fixation devices, with the aim of implementing a standard testing procedure for adjustable loop devices. The procedure consists of three test series, a loop shortening test and two different stability test series (singe device and tendon device test). Those test series are used to compare the performance of a new ALD from Arthrex (Naples, USA) with five competitor devices already on the market. In order to obtain representative results eight samples of each device are tested. In comparison to the previously performed studies, a complete unloading is applied in the stability tests, which allows for a detailed examination of the ALDs locking mechanisms in dynamically loaded test situations. Furthermore, the performed loop shortening tests reveal important aspects, such as the shortening accuracy and settling effects of the loops, that are not found in previous studies. Therefore, the used test protocol can be recommended for further testing.


2013 ◽  
Vol 404 ◽  
pp. 344-349
Author(s):  
Chen Ming Kuo ◽  
Gwo Chung Tsai ◽  
Wen Lin Yeh

This paper will take five male patients who performed a double-bundle anterior cruciate ligament (ACL) reconstruction to do finite element analysis and compare the stress distributions with each other. In order to lead this paper to reality, a model of the original bone tunnel according to CT is created and transformed into a finite-element model based on the reverse engineering method. The double-bundle ACL graft in the bone tunnel simulates the interference screw which screwed the ACL under the limit of friction and fix of contact. The dynamic analysis is performed with the femur flexion-extension axis which is under the limit of a fixed rotation angle (100°) and two degrees of freedom of motion in flexion. In the postprocess, the ACL graft is divided into several parts to get the stress distribution which will be easily to discuss the results. The result shows that max stress can be found on the top of the ACL or at the start point of the ACL because of the fixed position of the interference screw. The stress in PL bundle is greater than the stress in AM bundle. The angle of flexion will affect the stress and the stress might be higher at a specific angle.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1961
Author(s):  
Krzysztof Ficek ◽  
Jolanta Rajca ◽  
Mateusz Stolarz ◽  
Ewa Stodolak-Zych ◽  
Jarosław Wieczorek ◽  
...  

The exact causes of failure of anterior cruciate ligament (ACL) reconstruction are still unknown. A key to successful ACL reconstruction is the prevention of bone tunnel enlargement (BTE). In this study, a new strategy to improve the outcome of ACL reconstruction was analyzed using a bioresorbable polylactide (PLA) stent as a catalyst for the healing process. The study included 24 sheep with 12 months of age. The animals were randomized to the PLA group (n = 16) and control group (n = 8), subjected to the ACL reconstruction with and without the implantation of the PLA tube, respectively. The sheep were sacrificed 6 or 12 weeks post-procedure, and their knee joints were evaluated by X-ray microcomputed tomography with a 50 μm resolution. While the analysis of tibial and femoral tunnel diameters and volumes demonstrated the presence of BTE in both groups, the enlargement was less evident in the PLA group. Also, the microstructural parameters of the bone adjacent to the tunnels tended to be better in the PLA group. This suggested that the implantation of a bioresorbable PLA tube might facilitate osteointegration of the tendon graft after the ACL reconstruction. The beneficial effects of the stent were likely associated with osteogenic and osteoconductive properties of polylactide.


2016 ◽  
Vol 24 (3) ◽  
pp. 286-288
Author(s):  
Ravi Gupta ◽  
Anubhav Malhotra ◽  
Pawan Kumar ◽  
Gladson David Masih

Purpose To measure the femoral tunnel length created through a far medial portal and determine its correlation with body height, limb length, and thigh length in 404 Indian patients undergoing anterior cruciate ligament (ACL) reconstruction. Methods 364 male and 40 female Indian patients aged 18 to 51 (mean, 26.8) years underwent ACL reconstruction by a single surgeon using the hamstrings tendon autograft. Their body height, limb length, and thigh length were measured by a single assessor, as was the femoral tunnel length. Results The mean femoral tunnel length was 34.5 mm. It was <30 mm in 28 patients and <25 mm in 2 patients. The correlation coefficients of the femoral tunnel length with body height, limb length, and thigh length were 0.485 (p<0.0001), 0.426 (p<0.0001), and 0.304 (p<0.0001). No patient had posterior wall blowout fracture. Conclusion The femoral tunnel length positively correlated with body height, limb length, and thigh length in 404 Indian patients.


2017 ◽  
Vol 31 (08) ◽  
pp. 736-746 ◽  
Author(s):  
Jonathan Kosy ◽  
Vipul Mandalia

AbstractMechanoreceptors, within the anterior cruciate ligament (ACL), are believed to have importance in proprioception, contributing to dynamic knee stability. The potential for reinnervation of the ACL graft is one of the proposed advantages of remnant-preserving reconstruction. The aim of this review is to summarize advances in the basic science underpinning this function, alongside recent clinical studies, to define the current role for remnant-preservation.A comprehensive systematic review was performed using PubMed and Medline searches. Studies were analyzed with particular focus placed on the methodology used to either identify mechanoreceptors or test proprioception.Contemporary work, using immunohistological staining, has shown mechanoreceptors primarily within proximity to the bony attachments of the ACL (peripherally in the subsynovial layer). The number of these receptors has been shown to decrease rapidly, following rupture, with adhesion to the posterior cruciate ligament slowing this decline. Recent studies have shown proprioceptive deficits, in both the injured and contralateral knees, with the clinical relevance of findings limited by testing methodology and the small differences found. The advantages of remnant-preservation, seen primarily in animal studies, have not been shown in systematic reviews or meta-analysis of clinical studies.The potential for reinnervation of the graft is likely time-dependent and reliant on continued loading of the remnant. Therefore, current clinical use and future research should focus on preserving remnants within 6 months of injury that remain loaded by adherence to the posterior cruciate ligament. Subsequent testing should account for central neurological changes and focus on clinically relevant outcomes.


2018 ◽  
Vol 7 (5) ◽  
pp. 327-335 ◽  
Author(s):  
Y. Sato ◽  
R. Akagi ◽  
Y. Akatsu ◽  
Y. Matsuura ◽  
S. Takahashi ◽  
...  

Objectives To compare the effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament (ACL) reconstruction animal model. Methods Anterior cruciate ligament reconstruction using the plantaris tendon as graft material was performed on both knees of 24 rabbits (48 knees) to mimic ACL reconstruction by two different suspensory fixation devices for graft fixation. For the adjustable fixation device model (Socket group; group S), a 5 mm deep socket was created in the lateral femoral condyle (LFC) of the right knee. For the fixed-loop model (Tunnel group; group T), a femoral tunnel penetrating the LFC was created in the left knee. Animals were sacrificed at four and eight weeks after surgery for histological evaluation and biomechanical testing. Results Histologically, both groups showed a mixture of direct and indirect healing patterns at four weeks, whereas only indirect healing patterns were observed in both groups at eight weeks. No significant histological differences were seen between the two groups at four and eight weeks in the roof zone (four weeks, S: mean 4.8 sd 1.7, T: mean 4.5 sd 0.5, p = 0.14; eight weeks, S: mean 5.8 sd 0.8, T: mean 4.8 sd 1.8, p = 0.88, Mann-Whitney U test) or side zone (four weeks, S: mean 5.0 sd 1.2, T: mean 4.8 sd 0.4, p = 0.43; eight weeks, S: mean 5.3 sd 0.8,T: mean 5.5 sd 0.8, p = 0.61, Mann-Whitney U test) . Similarly, no significant difference was seen in the maximum failure load between group S and group T at four (15.6 sd 9.0N and 13.1 sd 5.6N) or eight weeks (12.6 sd 3.6N and 17.1 sd 6.4N, respectively). Conclusion Regardless of bone tunnel configuration, tendon-bone healing after ACL reconstruction primarily occurred through indirect healing. No significant histological or mechanical differences were observed between adjustable and fixed-loop femoral cortical suspension methods. Cite this article: Y. Sato, R. Akagi, Y. Akatsu, Y. Matsuura, S. Takahashi, S. Yamaguchi, T. Enomoto, R. Nakagawa, H. Hoshi, T. Sasaki, S. Kimura, Y. Ogawa, A. Sadamasu, S. Ohtori, T. Sasho. The effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament reconstruction: An animal study. Bone Joint Res 2018;7:327–335. DOI: 10.1302/2046-3758.75.BJR-2017-0238.R2.


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