scholarly journals Can the body slope of interference screw affect initial stability of reconstructed anterior cruciate ligament?: An in-vitro investigation

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Nazanin Daneshvarhashjin ◽  
Mahmoud Chizari ◽  
Javad Mortazavi ◽  
Gholamreza Rouhi

Abstract Background Superior biomechanical performance of tapered interference screws, compared with non-tapered screws, with reference to the anterior cruciate ligament (ACL) reconstruction process, has been reported in the literature. However, the effect of tapered interference screw’s body slope on the initial stability of ACL is poorly understood. Thus, the main goal of this study was to investigate the effect of the 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 screws were designed and fabricated. The diameters of both screws were 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, also through applying subsequent step of loading graft to the failure, maximum load to failure, and graft’s mode of failure were determined. Accordingly, the performance of the fabricated interference screws was compared with each other. Results HSTIS provides a greater graft-bone-screw construct stiffness, and a lower graft laxity, compared to LSTIS. Moreover, transverse rupture of graft fibers for LSTIS, and necking of graft in the HSTIS group were the major types of grafts’ failure. Conclusions HSTIS better replicates the intact ACL’s behavior, compared to LSTIS, by causing less damage in graft’s fibers; reducing graft laxity; and increasing fixation stability. Nonetheless, finding the optimal slope remains as an unknown and can be the subject of future studies.

2021 ◽  
Author(s):  
Nazanin Daneshvarhashjin ◽  
Mahmoud Chizari ◽  
SM Javad Mortazavi ◽  
Gholamreza Rouhi

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.


Author(s):  
M. Chizari ◽  
B. Wang ◽  
M. Snow

The natural history of Anterior Cruciate rupture is one of progressive deterioration of knee function, with the development of instability, meniscal tears and post traumatic osteoarthritis. The current surgical approach is for anatomical reconstruction using a biological tissue autograft. It is well understood that the initial stability is dependent on the strength of the fixation rather than the strength of the graft, until the graft becomes biologically incorporated in the bone tunnel. A study was carried out to better understand postoperative internal bone stresses in anterior cruciate ligament (ACL) reconstruction surgery. The mechanical aspects of an interface screw fixation were examined both experimentally and numerically, with the aim to minimize deleterious effects in ACL reconstruction. The tibial cortical/cancellous bony tunnel and the stress pattern resulting from the screw fixation in the tunnel are investigated.


2021 ◽  
Author(s):  
Yuanjun Teng ◽  
Lijun Da ◽  
Xiaohui Zhang ◽  
Hong Wang ◽  
Hua Han ◽  
...  

Abstract Background: Interference screw is commonly used for graft fixation in anterior cruciate ligament (ACL) reconstruction However, previous studies h a d reported that the insertion of interference screws significantly caused graft laceration . The purpose of this study was to determine whether sutures reduce d the graft laceration from the insertion of interference screws in ACL reconstruction. Methods: Porcine tibias and bovine extensor tendons were used for establishing a knee model of ACL reconstruction in vitro . The ends of grafts were sutured using three different sutures, including the bioabsorbable, Ethibond and ultra high molecular weight polyethylene (UHMWPE) sutures Poly ether ether ketone (PEEK) interference screw s w ere used fortibial fixation Biomechanical tests were performed to investigate the protective effects of different sutures on grafts Results : All prepared tendons and bone specimens showed similar characteristics (length, weight, and pre tension of the tendons, tibial bone mineral density) among all groups ( P 0.05). The biomechanical test s demonstrated that PEEK interference screw s significantly caused the graft laceration P 0.05). However, all sutures (the bioabsorbable, Ethibond and UHMWPE sutures) did not reduce the graft laceration in ACL reconstruction P 0.05). Conclusions : PEEK interference screw s significantly weakened the biomechanical properties of grafts during tibial fixation in ACL reconstruction. Absorbable Ethibond and UHMWPE sutures did not provide protective effects on grafts during ACL reconstruction.


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.


2017 ◽  
Vol 45 (6) ◽  
pp. 1349-1358 ◽  
Author(s):  
Jian-Chun Zong ◽  
Richard Ma ◽  
Hongsheng Wang ◽  
Guang-Ting Cong ◽  
Amir Lebaschi ◽  
...  

Background: Moderate graft pretensioning in anterior cruciate ligament (ACL) reconstruction is paramount to restore knee stability and normalize knee kinematics. However, little is known about the effect of graft pretensioning on graft-to-bone healing after ACL reconstruction. Hypothesis: Moderate graft pretensioning will improve bone formation within the bone tunnel after ACL reconstruction, resulting in superior load to failure. Study Design: Controlled laboratory study. Methods: 67 male Sprague-Dawley rats underwent unilateral ACL reconstruction with a flexor digitorum longus tendon autograft. The graft was subjected to pretensioning forces of 0 N, 5 N, or 10 N. Custom-made external fixators were used for knee immobilization postoperatively. Rats were euthanized for biomechanical load-to-failure testing (n = 45) and micro–computed tomography (μCT) examination (n = 22) at 3 and 6 weeks after surgery. Three regions of each femoral and tibial bone tunnel (aperture, middle, and tunnel exit) were chosen for measurement of tunnel diameter and new bone formation. Results: Biomechanical tests revealed significantly higher load-to-failure in the 5-N graft pretensioned group compared with the 0- and 10-N groups at 3 weeks (8.58 ± 2.67 N vs 3.96 ± 1.83 N and 4.46 ± 2.62 N, respectively) and 6 weeks (16.56 ± 3.50 N vs 10.82 ± 1.97 N and 7.35 ± 2.85 N, respectively) after surgery ( P < .05). The mean bone tunnel diameters at each of the 3 regions were significantly smaller in the 5-N group, at both the femoral and tibial tunnel sites, than in the 0- and 10-N groups ( P < .05). At 3 and 6 weeks postoperatively, the bone mineral density, bone volume fraction, and connectivity density around the aperture and middle regions of the tibial bone tunnels were all significantly higher in the 5-N group compared with the 0- and 10-N groups ( P < .05). In the aperture and middle regions of the femoral bone tunnels, pretensioning at either 5 or 10 N resulted in increased bone formation compared with the nonpretensioned group at 3 weeks postoperatively. No differences were found in bone formation between any of the 3 femoral tunnel regions at 6 weeks. Conclusion: Graft pretensioning can stimulate new bone formation and improve tendon-to-bone tunnel healing after ACL reconstruction. Clinical Relevance: Optimal graft pretensioning force in ACL reconstruction can improve bone tunnel healing. Further study is necessary to understand the mechanisms underlying the effect of graft pretensioning on healing at the bone-tunnel interface.


Author(s):  
Adam T. Hexter ◽  
Anita Sanghani-Kerai ◽  
Nima Heidari ◽  
Deepak M. Kalaskar ◽  
Ashleigh Boyd ◽  
...  

Abstract Purpose The effect of bone marrow mesenchymal stromal cells (BMSCs) and platelet-rich plasma (PRP) on tendon allograft maturation in a large animal anterior cruciate ligament (ACL) reconstruction model was reported for the first time. It was hypothesised that compared with non-augmented ACL reconstruction, BMSCs and PRP would enhance graft maturation after 12 weeks and this would be detected using magnetic resonance imaging (MRI). Methods Fifteen sheep underwent unilateral tendon allograft ACL reconstruction using aperture fixation and were randomised into three groups (n = 5). Group 1 received 10 million allogeneic BMSCs in 2 ml fibrin sealant; Group 2 received 12 ml PRP in a plasma clot injected into the graft and bone tunnels; and Group 3 (control) received no adjunctive treatment. At autopsy at 12 weeks, a graft maturation score was determined by the sum for graft integrity, synovial coverage and vascularisation, graft thickness and apparent tension, and synovial sealing at tunnel apertures. MRI analysis (n = 2 animals per group) of the signal–noise quotient (SNQ) and fibrous interzone (FIZ) was used to evaluate intra-articular graft maturation and tendon–bone healing, respectively. Spearman’s rank correlation coefficient (r) of SNQ, autopsy graft maturation score and bone tunnel diameter were analysed. Results The BMSC group (p = 0.01) and PRP group (p = 0.03) had a significantly higher graft maturation score compared with the control group. The BMSC group scored significantly higher for synovial sealing at tunnel apertures (p = 0.03) compared with the control group. The graft maturation score at autopsy significantly correlated with the SNQ (r = − 0.83, p < 0.01). The tunnel diameter of the femoral tunnel at the aperture (r = 0.883, p = 0.03) and mid-portion (r = 0.941, p = 0.02) positively correlated with the SNQ. Conclusions BMSCs and PRP significantly enhanced graft maturation, which indicates that orthobiologics can accelerate the biologic events in tendon allograft incorporation. Femoral tunnel expansion significantly correlated with inferior maturation of the intra-articular graft. The clinical relevance of this study is that BMSCs and PRP enhance allograft healing in a translational model, and biological modulation of graft healing can be evaluated non-invasively using MRI.


2021 ◽  
Vol 8 (18) ◽  
pp. 1258-1263
Author(s):  
Vishal Singh ◽  
Alokeshwar Sharma ◽  
Avinash Gundavarapu ◽  
Tejas Patel ◽  
Santosh Kumar M

BACKGROUND Traditionally, metallic interference screws were considered to have increased resistance to load than bio absorbable screws in anterior cruciate ligament (ACL) reconstruction. We did a comparative evaluation of biodegradable and metallic interference screws for tibial sided ACL reconstruction and also analysed complications, compared clinical outcome, did imaging study of ACL single bundle reconstruction by using titanium & newer poly–L-lactic acid (PLLA) bio absorbable screws to determine as to whether bio absorbable screw which costs double the metallic screw, is functionally better than standard metallic screws. METHODS This is a prospective comparative study conducted among 50 patients aged between 15 and 55 years with clinical and MRI confirmation of complete ACL tear, treated arthroscopically with ACL reconstruction with either bio absorbable (group 1) or metallic (group 2) interference screw and both the groups were compared on follow up for an average duration of 12 months. Lysholm and Gillquist Knee Scoring Scale were used and outcome scores were divided into excellent, good, fair and poor. RESULTS In our study 41 patients were males and 9 were females. Bio screw was used in 24 males and 6 female patients. Metallic screw was used in 17 males and 3 females. Outcome score was excellent in 26 (52 %) cases, good in 18 (36 %) cases, fair in 4 (8 %) cases, poor in 2 (4 %) cases. The mean Lysholm score in bio absorbable group was 93.13 and in metallic group was 89.70. Knee effusion was higher in bio screw group and infection rate was higher in metallic group. CONCLUSIONS In our study, the difference between bio absorbable screw group and metallic screw group was insignificant with regard to final patient outcome. Final osseointegration was better with bio absorbable screw, but increased cost of implant and almost same results compared to metallic screw does not make the bio absorbable screw superior to its counterpart. KEYWORDS ACL, Bio Absorbable Interference Screws, Metallic Interference Screws


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