How Four Weeks of Implantation Affect the Strength and Stiffness of a Tendon Graft in a Bone Tunnel

2002 ◽  
Vol 30 (4) ◽  
pp. 506-513 ◽  
Author(s):  
Wamis Singhatat ◽  
Keith W. Lawhorn ◽  
Stephen M. Howell ◽  
Maury L. Hull
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Tendon Graft ◽  
Interference Screw ◽  
Bone Tunnel ◽  
Fixation Device ◽  
Fixation Devices ◽  
Soft Tissue Graft ◽  
Anterior Cruciate ◽  
Strength And Stiffness

Background For a tendon graft to function as an anterior cruciate ligament, the tendon must heal to the bone tunnel. We studied the effect of 4 weeks of implantation on the strength and stiffness of a tendon in a bone tunnel using two different fixation devices in an ovine model. Hypothesis The type of fixation device in anterior cruciate ligament reconstruction may affect early healing, which can be measured as the strength and stiffness of a tendon in a bone tunnel. Study Design Controlled laboratory study. Methods An extraarticular tendon graft reconstruction was performed in ovine tibias. The graft was fixed with either a bioresorbable interference screw or a WasherLoc. After 4 weeks of implantation the strength and stiffness of the complex and the tendon graft-bone tunnel interface were determined by incrementally loading specimens to failure. Results For the interference screw, the strength deteriorated 63% and the stiffness deteriorated 40%. For the WasherLoc, the strength was similar and the stiffness improved 136%. Conclusions The type of fixation device determines whether the strength and stiffness of a tendon in a bone tunnel increases or decreases after implantation. Clinical Relevance The pace of rehabilitation may need to be adjusted based on the type of fixation device used to secure a soft tissue graft.

scholarly journals Evaluation of Adjustable Loop Suspensory Anterior Cruciate Ligament Fixation Devices

2019 ◽  
Vol 5 (1) ◽  
pp. 505-507
Author(s):  
Mira Dreier ◽  
Samuel Bachmayer ◽  
Christian Baumgartner ◽  
Jörg Schröttner
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Bone Tunnel ◽  
Test Series ◽  
Fixation Device ◽  
Test Protocol ◽  
Graft Tension ◽  
Fixation Devices ◽  
Anterior Cruciate

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.

Miniplate Suture Button Augmentation for Soft Tissue Graft Tibial Fixation in Anterior Cruciate Ligament Reconstruction

2021 ◽  
Vol 104 (2) ◽  
pp. 277-285
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Interference Screw ◽  
Tibial Fixation ◽  
Suture Button ◽  
Soft Tissue Graft ◽  
Anterior Cruciate ◽  
Supplemental Fixation

Background: Anterior cruciate ligament (ACL) reconstruction requires reliable and rigid graft fixation. Tibial-sided fixation is frequently cited as the “weak point” of the femur-graft-tibia construct. Some authors have recommended supplemental fixation with a staple or screw suture to post improve the strength and stiffness of the fixation. However, with these fixations, there is a risk for symptomatic hardware. Miniplate is flatter than screw or staple and does not penetrate the bone when attached. It is used as a button for suspensory fixation to enhance interference screw tibial fixation. Objective: To evaluate the clinical outcomes of the miniplate suture button for supplemental soft tissue graft tibial fixation in ACL reconstruction. Materials and Methods: A retrospective study was carried out between August 2016 and December 2019. A total of 40 patients had undergone primary ACL reconstruction, performed with hamstring tendon grafts that were secured using a miniplate suture button for supplemental interference screw tibial fixation. A total of 18 patients were excluded, leaving 22 patients at 1-year follow-up. Results: At least 1-year follow-up, the remaining 22 patients had significant difference between preoperative and postoperative outcome of anterior drawer test, Lachman test and pivot shift test (p<0.05). Lysholm knee scores improved significantly from 54.0±12.53 to 90.04±5.38. However, 3 patients (13.6%) experienced symptomatic hardware pain and 3 patients (13.6%) tendered around the miniplate site. There were no radiographic changes in miniplate displacement, deformed or broken plate, and bony reaction around miniplate. Conclusion: The use of a miniplate suture button as a supplemental fixation showed adequate fixation strength and showed good results in postoperative manual ligament laxity test and functional scores at minimum 1-year follow-up. However, there is still symptomatic pain at the hardware site. Keywords: Anterior cruciate ligament reconstruction, Supplemental fixation, Suture button

Compaction of a Bone Dowel in the Tibial Tunnel Improves the Fixation Stiffness of a Soft Tissue Anterior Cruciate Ligament Graft

2005 ◽  
Vol 33 (5) ◽  
pp. 719-725 ◽  
Author(s):  
Stephen M. Howell ◽  
Phil Roos ◽  
Maury L. Hull
Keyword(s):  
Anterior Cruciate Ligament ◽  
Soft Tissue ◽  
Cruciate Ligament ◽  
Tibial Tunnel ◽  
Tendon Graft ◽  
Joint Line ◽  
Fixation Device ◽  
Yield Load ◽  
Anterior Cruciate Ligament Graft ◽  
Anterior Cruciate

Background Despite increasing attention on fixation of a soft tissue anterior cruciate ligament graft in the tibia, there have been no studies on the use of a bone dowel as a joint line fixation device for promoting fixation properties, especially stiffness at the time of implantation. Purpose To determine whether compacting a bone dowel into the tibial tunnel improves fixation stiffness, yield load, and resistance to slippage of a soft tissue anterior cruciate ligament graft. Study Design Controlled laboratory study. Methods A double-looped tendon graft was fixed at the distal end of the tibial tunnel with a WasherLoc in 24 calf tibias. The tibial tunnels were treated with or without a dowel of cancellous bone. The bone dowel was harvested from the tibial tunnel and then compacted into a tapered space anterior to the anterior cruciate ligament graft as a joint line fixation device. A cyclic load and measurement test was administered to determine fixation stiffness, yield load, slippage, and failure mode. Results The specimens with the bone dowel had 58 N/mm more stiffness (P =. 04); however, the yield load and resistance to slippage were similar in specimens with and without the bone dowel. Conclusions A bone dowel harvested from the tibial tunnel can be used as a joint line fixation device in series with a distal fixation method to improve initial fixation stiffness and increase the fit, which is known to enhance tendon graft-to-bone healing in the tibia.

scholarly journals Can the Body Slope of Interference Screw Affect Initial Stability of Reconstructed Anterior Cruciate Ligament?: In-vitro Investigation

2021 ◽  
Author(s):  
Nazanin Daneshvarhashjin ◽  
Mahmoud Chizari ◽  
SM Javad Mortazavi ◽  
Gholamreza Rouhi
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Interference Screw ◽  
Bone Tunnel ◽  
Interference Screws ◽  
Bone Screw ◽  
Initial Stability ◽  
In Vitro Investigation ◽  
Tunnel Diameter ◽  
Anterior Cruciate

Abstract Background Superior biomechanical performance of tapered interference screws, in regard to reconstruction of anterior cruciate ligament (ACL), compared with non-tapered screws, has been reported in the literature. However, the effect of tapered interference screw’s body slope on the initial stability of ACL is not studied yet. Thus, the main goal of this study was to investigate the effects of interference screw's body slope on the initial stability of the reconstructed ACL. Methods Based on the best screw-bone tunnel diameter ratios in non-tapered screws, two different tapered interference screw were designed and fabricated. The diameters of both screws were considered to be equal to bone tunnel diameter in one third of their length from screw tip, then they were gradually increased by 1mm, in the lower slope (LSTIS), and 2 mm, in the higher slope (HSTIS) screws. To simulate the ACL reconstruction, sixteen soft tissue grafts were fixed, using HSTIS and LSTIS, in synthetic bone blocks. Through applying sub-failure cyclic incremental tensile load, graft-bone-screw construct's stiffness and graft laxity in each cycle, and through applying subsequent step of loading graft to the failure, maximum load to failure, and graft’s mode of failure were determined. Accordingly, performance of the fabricated interference screws were compared with each other. Results HSTIS, compared to LSTIS, provides a greater graft-bone-screw construct stiffness, and a lower graft laxity. Moreover, transverse rupture of graft fibers for LSTIS, and necking of graft in HSTIS group were the major types of grafts' failure. ConclusionHSTIS compared to LSTIS, by causing less damage in graft's fibers; reducing graft laxity; and increasing fixation stability, better replicates the intact ACL's behavior.

A Higher Initial Tensioning Force of an ACL Graft Results in a Higher Graft Force After Screw Fixation Irrespective of the Screw Diameter: A Biomechanical Study

2021 ◽  
pp. 036354652110478
Author(s):  
M. Enes Kayaalp ◽  
Robert Collette ◽  
Philipp Kruppa ◽  
Anne Flies ◽  
Klaus-Dieter Schaser ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Soft Tissue ◽  
Screw Fixation ◽  
Cruciate Ligament ◽  
Interference Screw ◽  
Biomechanical Study ◽  
Bioabsorbable Interference Screw ◽  
Soft Tissue Graft ◽  
Screw Diameter ◽  
Anterior Cruciate

Background: The intra-articular graft force (IAGF) in anterior cruciate ligament reconstruction decreases quickly over the first hours after surgery. Nevertheless, little is known about whether the initial extra-articular tensioning force (EATF) and screw diameter affect the graft force after fixation. Purpose: To investigate the effects of different EATFs on the IAGF of a soft tissue graft fixated via a bioabsorbable interference screw over 100 minutes after fixation and to evaluate the effects of different screw diameters within 1 mm of the tunnel width during this process. Study Design: Controlled laboratory study. Methods: In this biomechanical study, a porcine quadruple-strand soft tissue graft was inserted into the tibial anterior cruciate ligament tunnel. On the extra-articular side, 3 loads were applied during retrograde insertion of the bioabsorbable interference screw (6, 7, and 8 mm): 20 N, 80 N, and maximum manual EATF (Nmax). Nine study groups consisting of 10 tibiae each were created to test the effects of different EATFs and screw sizes. The IAGF was measured up to 100 minutes after the EATF was released. Results: An EATF ≥80 N resulted in a larger IAGF for all screw sizes at 100 minutes. There were no significant associations between the IAGF at 100 minutes and different screw diameters. Inserting the tibial screw significantly increased the IAGF in all groups, with the exception of Nmax applied in groups with 7- or 8-mm screws. When compared with the end of screw insertion, after the release of the EATF, the IAGF dropped by 55% to 77 % at 100 minutes. Conclusion: An initial EATF ≥80 N is associated with a significantly larger IAGF at 100 minutes in this cadaveric simulation. The IAGF in soft tissue grafts decreased substantially after the retrograde placement of an interference screw. A recommendation regarding screw diameter with respect to the IAGF cannot be given. Clinical Relevance: To obtain a higher residual graft force after bioabsorbable interference screw fixation, an initial EATF ≥80 N should be applied according to this model. The significant decrease in graft force after the release of the EATF indicates that the reconstructed knee cannot be mechanically stabilized after the surgery.

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