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In the present study, a polyethylene terephthalate (PET) artificial ligament was coated with an organic layer-by-layer (LBL) self-assembled template of chitosan and hyaluronic acid, and then incubated in a calcium phosphate (CaP) solution to prepare a biomimetic CaP coating. The surface characterization of the ligament was examined using scanning electron microscopy, atomic force microscopy and energy-dispersive X-ray spectroscopy. The effects of CaP coatings on the osteogenic activity of MC3T3 E1 mouse osteoblastic cells were investigated by evaluating their attachment, proliferation and the relative expression levels of alkaline phosphatase. The results revealed that the organic LBL template on the PET artificial ligament was effective for CaP apatite formation. Following incubation for 72 h, numerous nanoscale CaP apatites were deposited on the PET ligament fibers. In addition, the results of the in vitro culture of MC3T3-E1 mouse osteoblastic cells demonstrated that the CaP coating had a good biocompatibility for cell proliferation and adhesion, and the CaP-coated group had a significantly higher alkaline phosphatase activity compared with the uncoated control group after seven days of cell culture. Collectively, these results demonstrated that the biomimetic nanoscale CaP-coated PET artificial ligaments have potential in bone-tissue engineering. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate whether a periosteum patch could enhance polyethylene terephthalate (PET) artificial ligament graft osseointegration in a bone tunnel. 12 female goats underwent ACL reconstruction with a PET artificial ligament graft in the right knees. Right knees in 6 goats were reconstructed with periosteum patch-enveloped PET grafts (Periosteum group) in the tibia bone tunnel, whereas the other 6 goats had no periosteum patch and served as the Control group. All the goats were sacrificed at 12 months after surgery. 3 tibial-graft complex samples in each group were harvested consecutively for microcomputed tomography (micro-CT) scan, magnetic resonance imaging (MRI) scan and histological evaluation. The other 3 tibial-graft complex samples in each group were harvested for biomechanical testing. The mean pull-out load of the Periosteum group (208±25N) at 12 months was significantly higher than that of the Control group (1O7±13JV) (p = 0.0044). According to the micro-CT scan, more new bone formation was observed at the graft-bone interface in the Periosteum group compared with the Control group. Furthermore, MRI showed that the Periosteum group appeared to have a better graft osseointegration within the bone tunnel compared with the Control group. Histologically, application of a periosteum patch induced more new bone and Sharpey's fiber formation between the graft and bone tunnel compared with the controls. The study has shown that periosteum enveloping of the PET artificial ligament has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel. [ABSTRACT FROM AUTHOR]

The aim of this research was to produce artificial anterior cruciate ligaments (ACL) using the weaving (plain and leno) and braiding techniques, and to compare the mechanical and fatigue life properties of these ligaments with the natural ACL. For this purpose, tubular fabric structures were produced on braiding and weaving machines from polyester and Vectran yarns. To turn these structures into ligaments, the core of the tubes were filled with straight yarns. The mechanical properties of the resulted ligaments were tested before and after a fatigue test. The results showed that all produced ligaments provide enough tensile strength and breaking elongation when they were compared with the natural ACL mechanical properties. After the fatigue test, the tensile strength of ligaments did not decline substantially. Regarding the tensile strength, the leno weaving structure has the most similar properties to the natural ACL. The leno weaving ligament made from Vectran has one-third of the strain percentage of the natural ACL. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether augmented remnant repair could enhance polyethylene terepthalate (PET) artificial ligament graft ligamentization. 12 female goats underwent ACL reconstruction with PET artificial ligament graft in the right knees. Right knees in 6 goats were reconstructed with augmented remnant repair (Remnant group), whereas the other 6 goats had no augmented remnant repair comprised the Control group. 3 goats in each group were randomly sacrificed at 6 months and 12 months respectively after surgery. The intra-articular parts of the reconstructed grafts were harvested for histological evaluation. Well-vascularized tissue ingrowth within the artificial ligament was observed in the remnant group at 12 months postoperatively. Collagen-I content of graft was significantly higher in the Remnant group than in the Control group at each time point (p<0.05). The relative expression of collagen-III positive area of the remnant-preserved group was significantly higher than that of the Control group at 12 months (p = 0.005). The vascular endothelial growth factor (VEGF)-positive or CD31-positive area in the graft appeared higher in the Remnant group compared with the Control group at 6 months. Remnant repair enhanced the revascularization and remodeling of the PET artificial ligament in ACL reconstruction. [ABSTRACT FROM AUTHOR]

Background: Recent improvements in manufacturing of biomaterials have made available a new generation of artificial ligaments with better biocompatibility and design that have led to a new interest in using them for ACL reconstructions. Purpose: To evaluate the biomechanical characteristics of four femoral fixations using a Ligament Advanced Reinforcement System (LARS™ AC; LARS, Arc sur Tille, France) for anterior cruciate ligament replacement. Method: Six femoral ACL fixations in four configurations using fresh calf femurs with an interference titanium screw inserted inside to outside, an interference titanium screw inserted outside to inside, an interference titanium screw inserted inside to outside with a staple and a new transversal cortical suspension device developed by LARS™ were compared in a static loading and failure test. Output values were ultimate strength, graft slippage, mode of failure, energy to failure and stiffness. Results: The transversal fixation performed with a significantly higher failure load than others (1804 N) ( p < 0.001), whereas there were no significant differences between the three fixations with interference screws. There were no significant differences of stiffness between all fixations, and the transversal device had a significantly higher graft slippage (13.1 mm) than others (all p < 0.01). Conclusions: In this in vitro evaluation, the transversal fixation exhibited better biomechanical performance under static solicitations than others. The transversal device is expected to provide better clinical results than the well-established screw system fixations for femoral ACL fixation. Clinical relevance: Laboratory investigation (Level 2). [ABSTRACT FROM AUTHOR]

This review comprehensively covers research conducted to enhance polyethylene terephthalate (PET) artificial ligament osseointegration in the bone tunnel. These strategies, using biocompatible or bioactive coatings, had a positive effect in promoting PET ligament osseointegration by increasing bone formation and decreasing fibrous scar tissue at the ligament-to-bone interface. The improved osseointegration can be translated into a significant increase in the biomechanical pull-out loads. However, the load-to-failure of coated ligament is far lower than that of native ACL. Coatings to promote intra-articular ligamentization are also discussed in this study. Collectively, our investigations may arouse further study of the biological coating of PET artificial ligaments in order to effectively enhance ligament osseointegration and promote artificial ligament ligamentization. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 839-845, 2015. [ABSTRACT FROM AUTHOR]

Synthetic ligament for anterior cruciate ligament (ACL) reconstruction has been widely used in the past. Long-term follow-up has demonstrated the unreliability of many of these devices in ACL surgery, and problems may arise for the surgeon approaching a patient with failed artificial ligament reconstruction. The aim of this study is to investigate whether revision surgery may improve clinical and radiographic outcomes in patients with failed synthetic ACL reconstruction. Fourteen patients who were treated in the past with ACL reconstruction with synthetic grafts underwent two-stage revision surgery. Follow-up averaged 4.2 years (range 2-6 years). Mean KOOS score was 75.8 (SD 10.2); IKDC score was B in two patients, C in nine and D in three. The improvement compared to preoperative status was not statistically significant ( p > 0.05). Four patients were positive to Lachman and anterior drawer tests. Mean side-to-side anterior laxity averaged 4.3 mm (SD 1.2). Biopsy specimens documented the presence of foreign body granulomatous reaction, giant foreign body cells and polyethylene wear particles. The level of osteoarthritis worsened at follow-up compared to preoperative status ( p < 0.05). ACL revision surgery with autografts in patients who underwent previous failed primary synthetic ligament reconstruction does not improve clinical outcomes and does not influence the natural history of knee osteoarthritis started from artificial ligament debris. [ABSTRACT FROM AUTHOR]

Background and Objective: Anterior cruciate ligament (ACL) reconstruction calls for artificial ligaments with better bioactivity, however systematic reviews regarding bioactivity enhancement strategies, technologies, and perspectives of artificial ligaments have been rarely found., Methods: Research papers, reviews, and clinical reports related to artificial ligaments were searched and summarized the current status and research trends of artificial ligaments through a systematic analysis., Results: Having experienced ups and downs since the very first record of clinical application, artificial ligaments differing in material, and fabrication methods have been reported with different clinical performances. Various manufacturing technologies have developed and realized scaffold- and cell-based strategies. Despite encouraging in-vivo and in-vitro test results, the clinical results of such new designs need further clinical examinations., Conclusion: As the demand for ACL reconstruction dramatically increases, novel artificial ligaments with better osteoinductivity and mechanical performance are promising., The Translational Potential of This Article: To develop novel artificial ligaments simultaneously possessing excellent osteoinductivity and satisfactory mechanical performance, it is important to grab a glance at recent research advances. This systematic analysis provides researchers and clinicians with comprehensive and comparable information on artificial ligaments, thus being of clinical translational significance., Competing Interests: The authors declare no conflict of interest., (© 2022 The Authors.)

Objective: Anterior cruciate ligament (ACL) reconstruction using a new generation of artificial ligaments (NGAL) gained popularity in China owing to its good effectiveness and early functional recovery, but iatrogenic surgical failures and preconceived misconceptions have seriously affected its standardized clinical application. A specialist consensus is now developed to provide guidance and reference for orthopaedic sports medicine doctors when adopting or considering the NGAL for ACL reconstruction., Methods: The consensus on the core techniques and adverse events in ACL reconstruction using the NGAL was developed by a modified Delphi method, referring exclusively to the NGAL for ACL reconstruction approved by the National Medical Products Administration (NMPA). Consensus specialists were selected from the members of the Chinese Association of Orthopaedic Surgeons (CAOS) and the Chinese Society of Sports Medicine (CSSM). The drafting team summarized the draft consensus terms based on medical evidence and organized rounds of investigation: two rounds of online questionnaire investigation and the final round of face-to-face meeting. After discussion, revision, and voting, a consensus on the draft consensus term was reached when the agreement rate exceeded 85%. The consensus terms were categorized as "strong" (agreement rate: 95.0%-100%), "moderate" (agreement rate: 90.0%-94.9%), and "basic" (agreement rate: 85.0%-89.9%)., Results: Thirty-one specialists completed the questionnaire investigation. They all practiced in university teaching hospitals (Grade-A tertiary hospitals) from 16 provinces, autonomous regions, and municipalities in China. Among them, 28 were chief physicians and 3 were associate chief physicians; 22 were professors and 7 were associate professors; the average seniority in orthopedic sports medicine was 25.2 years (range, 12-40 years); the average seniority in performing ACL reconstruction procedures was 13.2 years (range, 7-23 years); in terms of the number of ACL reconstruction using the NGAL, 18 completed more than 100 cases, of which 6 had more than 300 cases; in terms of research, 28 had published more than 1 related paper in the past 5 years, of which 13 had published more than 3 related papers. Twenty-six specialists attended the face-to-face meeting and reached a consensus on 9 terms, including 8 strong terms and 1 moderate term., Conclusion: ACL reconstruction using the NGAL must deploy "isometric" or "near-isometric" reconstruction and should preserve the natural ACL remnants as much as possible. Bone tunnel positioning can be performed using intraoperative radiographic measurements or the lateral femoral intercondylar ridge as reference marks. Incorrect positioning of the bone tunnel is the main reason of surgical failure, and there is a lack of consensus on handling interference screws during revision. Bone tunnel enlargement exists after reconstruction but rarely causes related symptoms. Synovitis and infection are uncommon complications. The aging effect of polyethylene terephthalate fiber on the long-term clinical outcomes is unknown and deserves attention.

Background: Graft choice is an important step in the pre-operative plan of anterior cruciate ligament reconstruction (ACLR). The four-strand hamstring tendon (4SHT) is the most widely used auto-graft, while the Ligament Advanced Reinforcement System (LARS) is the newest typical biomaterial for ACLR. The physical activity level (PAL) before injury can affect the efficacy and outcomes of ACLR. This study aims to compare the efficacy and functional outcomes between ACLR using LARS and 4SHT in patients different PALs. Methods: This was a prospective paired case-control study. ACL rupture patients included from 1 January 2017 to 31 December 2019 were subsequently divided into the high and plain PAL groups, according to their baseline PAL before injury. Clinical assessments included: Lachman test, pivot shift test, ligament laxity, Lysholm and International Knee Documentation Committee (IKDC) scores, and rate of returning to sports. The minimum follow-up was 2 years (y). Results: A total of 58 patients had accomplished the 2 y follow-up (missing rate: 6.5%). In the high PAL group (n = 22), the positive rate of A-P laxity of the LARS subgroup was lower than the 4SHG subgroup ( p = 0.138), while the Lysholm score ( p = 0.002), IKDC score ( p = 0.043), and rate of returning to sports ( p = 0.010) of the LARS were higher than the 4SHG at 1 year follow-up; the positive rates of A-P laxity ( p = 0.009) and pivot test ( p = 0.027) were lower in the LARS than the 4SHG at 2 y follow-up. In the plain PAL group (n = 36), the positive rate of A-P laxity in the LARS subgroup was lower than the 4SHG at 1 year follow-up ( p = 0.017); the positive rates of A-P laxity ( p = 0.001), Lachman ( p = 0.034), and pivot tests ( p = 0.034) in the LARS were also lower than the 4SHG at 2 y follow-up, but the IKDC score ( p = 0.038) and rate of returning to sports ( p = 0.019) in the 4SHG were higher than the LARS. Conclusion: In patients with high PAL, LARS can acquire better knee stability, sooner functional recovery, and returning to sports than 4SHG, while in patients without high PAL, 4SHG acquires better functional outcomes and a higher rate of returning to sports., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ma, Wang and Xu.)

The optimized graft for use in anterior cruciate ligament (ACL) reconstruction is still in controversy. The bone-patellar tendon-bone (BPTB) autograft has been accepted as the gold standard for ACL reconstruction. However, donor site morbidities cannot be avoided after this treatment. The artificial ligament of ligament advanced reinforcement system (LARS) has been recommended for ACL reconstruction. The purpose of this study is to compare the midterm outcome of ACL reconstruction using BPTB autografts or LARS ligaments. Between July 2004 and March 2006, the ACL reconstruction using BPTB autografts in 30 patients and LARS ligaments in 32 patients was performed. All patients were followed up for at least 4 years and evaluated using the Lysholm knee score, Tegner score, International Knee Documentation Committee (IKDC) score, and KT-1000 arthrometer test. There were no significant differences between the two groups with respect to the data of Lysholm scores, Tegner scores, IKDC scores, and KT-1000 arthrometer test at the latest follow-up. Our study demonstrates that the similarly good clinical results are obtained after ACL reconstruction using BPTB autografts or LARS ligaments at midterm follow-up. In addition to BPTB autografts, the LARS ligament may be a satisfactory treatment option for ACL rupture. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the impact of polystyrene sodium sulfonate (PolyNaSS) grafting onto the osseo-integration of a polyethylene terephthalate artificial ligament (Ligament Advanced Reinforcement System, LARS™) used for Anterior Cruciate Ligament (ACL). The performance of grafted and non-grafted ligaments was assessed in vitro by culturing human osteoblasts under osteogenic induction and this demonstrated that the surface modification was capable of up-regulating the secretion of ALP and induced higher level of mineralisation as measured 6 weeks post-seeding by Micro-Computed Tomography. Grafted and non-grafted LARS™ were subsequently implanted in an ovine model for ACL reconstruction and the ligament-to-bone interface was evaluated by histology and biomechanical testings 3 and 12 months post-implantation. The grafted ligaments exhibited more frequent direct ligament-to-bone contact and bone formation in the core of the ligament at the later time point than the non-grafted specimens, the grafting also significantly reduced the fibrous encapsulation of the ligament 12 months post-implantation. However, this improved osseo-integration was not translated into a significant increase in the biomechanical pull-out loads. These results provide evidences that PolyNaSS grafting improved the osseo-integration of the artificial ligament within the bone tunnels. This might positively influence the outcome of the surgical reconstructions, as higher ligament stability is believed to limit micro-movement and therefore permits earlier and enhanced healing. [Copyright &y& Elsevier]

A plasma- and precursor-assisted biomimetic process utilizing plasma and alternate dipping treatments was applied to a Leeds-Keio artificial ligament to produce a thin coating of apatite in a supersaturated calcium phosphate solution. Following plasma surface modification, the specimen was alternately dipped in calcium and phosphate ion solutions three times (alternate dipping treatment) to create a precoating containing amorphous calcium phosphate (ACP) which is an apatite precursor. To grow an apatite layer on the ACP precoating, the ACP-precoated specimen was immersed for 24 h in a simulated body fluid with ion concentrations approximately equal to those in human blood plasma. The plasma surface modification was necessary to create an adequate apatite coating and to improve the coating adhesion depending on the plasma power density. The apatite coating prepared using the optimized conditions formed a thin-film that covered the entire surface of the artificial ligament. The resulting apatite-coated artificial ligament should exhibit improved osseointegration within the bone tunnel and possesses great potential for use in ligament reconstructions. [ABSTRACT FROM AUTHOR]

Prosthetic devices for anterior cruciate ligament (ACL) reconstruction have been unsuccessful due to mechanical failure or chronic inflammation. Polymer hydrogels combine biocompatibility and unique low friction properties; however, their prior use for ligament reconstruction has been restricted to coatings due to insufficient tensile mechanics. Here, we investigate new constructs of polyvinyl alcohol (PVA) hydrogel fibers. In water, these fibers swell to an equilibrium water content of 50% by weight, retaining a tensile modulus greater than 40 MPa along the fiber axis at low strain. Rope constructs were assembled for ACL replacement and mechanical properties were compared with data from the literature. Pure PVA hydrogel constructs closely reproduce the non-linear tensile stiffness of the native ACL with an ultimate strength of about 2000 N. An additional safety factor in tensile strength was achieved with composite braids by adding ultrahigh molecular weight polyethylene (UHMWPE) fibers around a core of PVA cords. Composition and braiding angle are adjusted to produce a non-linear tensile behavior within the range of the native ligament that can be predicted by a simple rope model. This design was found to sustain over one million cycles between 50 and 450 N with limited damage and less than 20% creep. The promising mechanical performances of these systems provide justification for more extensive in vivo evaluation. [ABSTRACT FROM AUTHOR]

The ideal artificial ligament graft should have favorable biocompatibility to facilitate cell adhesion, proliferation, and collagen regeneration. In this present study, surface modifica-tion was performed on a poly(ethylene terephthalate) (PET) artificial ligament graft by layer-by-layer (LBL) self-assembly coating of hyaluronic acid (HA) and chitosan (CS). The surface characterization of the ligament was examined using scanning electron microscopy, atomic force microscopy, and energy-dispersive X-ray spectroscopy. The results of in vitro culturing of human foreskin fibroblast cells supported the hypothesis that the LBL coating of CS-HA could promote the cell proliferation and adhesion on the sheets. A rabbit medi-cal collateral ligament reconstruction model was used to evaluate the effect of this LBL coating in vivo. The final results proved that this LBL coating could significantly promote and enhance new collagen formation among the graft fibers. On the basis of these results, we conclude that such CS-HA assembly coating could enhance PET graft biocompatibility in vitro and in vivo, and a CS-HA-coated PET graft has considerable potential as a desirable substitute for ligament reconstruction. [ABSTRACT FROM AUTHOR]

Background: We aimed to prospectively investigate the clinical outcomes of medial patellofemoral ligament (MPFL) reconstruction using polyester high-strength suture tape with knotless anchors., Method: Forty-three patients (65 knees) were followed for at least 1 year postoperatively, with 27 patients (43 knees) followed for 2 years postoperatively. All patients underwent MPFL reconstruction using polyester high-strength suture tape (FiberTape®; Arthrex) with knotless anchors (SwiveLock®; Arthrex). Repeated dislocation and residual patellar apprehension signs were recorded, and congruence and tilting angles were measured. Changes in Knee Injury and Osteoarthritis Outcome Scale (KOOS) scores and their associations with the preoperative tibial tubercle-trochlear groove (TT-TG) distance were analyzed., Results: No repeat dislocations (0%) were observed. One (2.4%) residual positive patellar apprehension sign was noted. The mean tilting angle decreased from 24.8° to 10.7° (P < 0.001), and the mean congruence angle decreased from 24.9° to 4.3° (P < 0.001). At 2 years follow up, all KOOS subscales had improved: pain (92.0 ± 12.9), symptoms (90.2 ± 11.9), activities of daily living (95.7 ± 7.3), sports activity (85.7 ± 16.9), quality of life (87.7 ± 12.9), and patellofemoral (89.0 ± 9.6) outcomes. KOOS subscale scores improved regardless of the preoperative TT-TG distance (21.1 ± 3.5 mm; range, 13.8-29.9 mm)., Conclusions: MPFL reconstruction using FiberTape and knotless SwiveLock anchors was performed without sacrificing autologous tissue. No recurrent patellar dislocation was observed during the 2-year follow up period. All KOOS subscale scores improved using FiberTape and SwiveLock anchors in MPFL reconstruction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Hydroxyapatite (HA) based materials have been widely used in the field of ligament tissue engineering in the past decades. It has been previously reported that HA can increase the penetration of marrow-derived mesenchymal stem cells (MSCs) and MSCs cells into scaffolds due to increased cell differentiation in biological media. Additionally, it was found that there are much difference between MSCs and anterior cruciate ligament (ACL) cells. For that reason, we mainly evaluate the biocompatibility of polyethylene terephthalate (PET) silk scaffold with fibroblasts cells in vitro. We cultured mouse fibroblasts cells on the substrate of PET fiber and PET-HA scaffold, respectively, and then observed the morphology by using scanning electron microscopy. Our data indicate that PET-HA scaffold has good biocompatibility with fibroblasts cells and can potentially be useful in enhancing the fibroblasts cell differentiation and proliferation. [ABSTRACT FROM AUTHOR]

Abstract: In this study layer by layer (LBL) self-assembled coatings of hyaluronic acid (HA) and cationized gelatin (CG) were used to modify polyethylene terephthalate (PET) artificial ligament grafts. Changes in the surface properties were characterized by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and contact angle and biomechanical measurements. The cell compatibility of this HA–CG coating was investigated in vitro on PET films seeded with human foreskin dermal fibroblasts over 7days. The results of our in vitro studies demonstrated that the HA–CG coating significantly enhanced cell adhesion, facilitated cell growth, and suppressed the expression of inflammation-related genes relative to a pure PET graft. Furthermore, rabbit and porcine anterior cruciate ligament reconstruction models were used to evaluate the effect of this LBL coating in vivo. The animal experiment results proved that this LBL coating significantly inhibited inflammatory cell infiltration and promoted new ligament tissue regeneration among the graft fibers. In addition, the formation of type I collagen in the HA–CG coating group was much higher than in the control group. Based on these results we conclude that PET grafts coated with HA–CG have considerable potential as substitutes for ligament reconstruction. [Copyright &y& Elsevier]

Abstract: Even though modern ski bindings can prevent tibia fractures they are still unable to reliably protect the knee. Attempts are therefore made to develop mechatronic concepts to implement additional release criteria. In order to systematically test and optimize such new bindings an artificial instrumented knee joint is currently being constructed at our Institute. A major challenge in this development is to measure the tension forces in the artificial ligaments. To provide this demanding measuring, a novel sensor fiber made of silicon rubber and filled with carbon black was used, which alters its electrical conductivity due to elongation. The fiber itself was either bonded or sewn on the synthetic ligament (LARS, Corin Group PLC, UK). To check the linearity, reproducibility and accuracy of the new measurement unit, tensile tests have been conducted using a similar method as proposed by another study on sensor fibers. As a result, the tests revealed good quality of the developed measurement application, showing minimal variance and high reproducibility. Thus it turned out to be a reliable and appropriate tool to record forces in a uniaxial direction making it an interesting device not only in our application but generally as a method to measure tension in sports apparel and other fabrics. [Copyright &y& Elsevier]

Copyright of Operative Orthopädie und Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Surface coating with an organic layer-by-layer self-assembled template of chitosan and hyaluronic acid on a poly(ethylene terephthalate) (PET) artificial ligament was designed for the promotion and enhancement of graft-to-bone healing after artificial ligament implantation in a bone tunnel. The results of in vitro culturing of MC3T3-E1 mouse osteoblastic cells supported the hypothesis that the layer-by-layer coating of chitosan and hyaluronic acid could promote the cell compatibility of grafts and could promote osteoblast proliferation. A rabbit extra-articular tendon-to-bone healing model was used to evaluate the effect of this kind of surface-modified stainless artificial ligament in vivo. The final results proved that this organic compound coating could significantly promote and enhance new bone formation at the graft-bone interface histologically and, correspondingly, the experimental group with coating had significantly higher biomechanical properties compared with controls at 8 weeks (P < 0.05). [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study is to evaluate the midterm results of using Ligament Advanced Reinforcement System (LARS) artificial ligament for augmentation of the short (<15cm length) and small-sized (3–4mm) diameter for the gracilis and (4–5mm) for the semitendinosus harvested hamstring tendons in anterior cruciate ligament (ACL) reconstruction, and to assess the knee stability, patient satisfaction and early- and midterm complications following surgery. A total of 112 patients were included in this study and were operated with arthroscopic ACL reconstruction using (augmented hamstring tendon graft with LARS) between January 2004 and December 2006. Assessment before and after the surgery include the history, clinical examination, modified international knee documentation committee score (IKDC), KT1000 measurements for clinical knee stability and osteoarthritis outcome score (KOOS) for patient satisfaction. Clinical results measured by IKDC evaluation, KT1000 and Lysholm scores showed significant postoperative values compared with the preoperative ones. Our findings suggest that at the end of a 5-year follow-up, augmented hamstring tendon graft with LARS artificial ligament is a useful, safe and satisfactory treatment option for ACL reconstruction in deficient knees with short- and small-sized harvested hamstring tendons, especially when an early return to high levels of sport activity is needed. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to determine the effect of the combination of hydroxyapatite (HA) and bioglass (BG) on polyethylene terephthalate (PET) artificial ligament graft osseointegration within the bone tunnel. The results of in vitro culturing of MC3T3-E1 mouse osteoblastic cells proved that this HA/BG composite coating can promote the cell compatibility of grafts. A rabbit extraarticular tendon-to-bone healing model was used to evaluate the effect of this composite coating on PET artificial ligaments in vivo. The final results demonstrated that HA/BG coating improved new bone formation at the graft-bone interface and increased the load-to-failure property of graft in bone tunnel compared to the control group at early time. The study has shown that HA/BG composite coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel. [Copyright &y& Elsevier]

Introduction: In an attempt to fill a gap between simple decompression alone and fusion in the spectrum of surgical treatment for degenerative lumbar spinal stenosis (DLSS), the authors sought to demonstrate the efficacy and reproducibility of soft stabilization with interspinous artificial ligament after microsurgical fenestration to prevent post-decompression segmental instability for mildly unstable DLSS. Materials and methods: Clinical outcomes from 556 patients treated with soft stabilization with artificial ligament following microdecompression for mildly unstable DLSS from March 1998 to June 2006 were retrospectively obtained from three institutions in three countries. Outcomes were measured at a mean of 48.9 months after surgery using MacNab criteria. Peri- and postoperative complications and revision surgery cases were also analyzed. Results: Follow-up was achieved in 391 (70.3%) of the 556 patients. Clinical outcomes were excellent in 43.7%, good in 36.7%, fair in 12.2%, and poor in 7.4% of the patients. The overall clinical success rate was 80.4%. No major complications except postoperative hematoma and wound infection (6/391 cases, 1.5%) were observed, and few revision surgeries (2.3%) were done during follow-up. Conclusion: We found favorable and reproducible results with soft stabilization with artificial ligament after microdecompression for mildly unstable DLSS from three institutions in three countries. Soft stabilization with artificial ligament may be concluded to represent an effective prevention of increased post-decompression instability with reliable reproducibility for mildly unstable DLSS in carefully selected patients. [ABSTRACT FROM AUTHOR]

Copyright of IRBM is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, artificial anterior cruciate ligaments were manufactured using braiding process. The mechanical behaviour of circular braids under tensile loads was studied. These braids were manufactured from different yarns and materials. A study of the effect of yarns characteristics and the machine parameters on the braid mechanical properties was done. Predictive models of the braid mechanical response based on the constituent yarn characteristics and the machine parameters have been developed. The last part of this study has been devoted to optimise the braid mechanical properties to be close to those of native ligament. [ABSTRACT FROM AUTHOR]

Artificial ligaments are a useful tool in ligament reconstruction. Although the new generation of artificial ligaments shows encouraging clinical results, in contrast to earlier generations studies on the biological properties are lacking. Biopsies were taken from a ligament advancement reinforcement system (LARS) 6 months after implantation and investigated by histochemistry. An in vitro study seeding human fibroblasts or osteoblast-like cells (up to 106 cells for 21 days) on ligament pieces (5 × 5 mm) was conducted and analyzed by histochemistry. The biopsies showed complete cellular and connective tissue ingrowth in the LARS ligament. In vitro fibroblasts and osteoblast-like cells encapsulated the fibers by building a cellular net around them. To our knowledge, these findings demonstrate for the first time the cellular ingrowth into the LARS ligament. This mechanism might explain the strength and the inert behavior of the ligament without the synovialitis shown in clinical studies. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the effect of combined posterior cruciate ligament (PCL) and postero-lateral corner (PLC) reconstruction on laxity and three-dimensional kinematics of cadaver knees. We performed anatomical double bundle PCL reconstruction, and functional one bundle ‘over-the-bottom’ PCL reconstruction combined with one type of PLC reconstruction, running from the postero-lateral tibia to an isometric point near the lateral epicondyle of the femur. Our results showed that combined reconstruction was necessary to restore rotatory laxity. PLC reconstruction, according to the technique described, invariably created a shift towards internal rotation of the kinematic curves, compared to the intact knee. [Copyright &y& Elsevier]

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Copyright of Orthopédie Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background/objectives: Polyethylene terephthalate (PET)-based artificial ligaments are one of the most commonly used grafts in anterior cruciate ligament (ACL) reconstruction surgery. However, the lack of favorable hydrophilicity and cell attachment for PET highly impeded its widespread application in clinical practice. Studies found that surface modification on PET materials could enhance the biocompatibility and bioactivity of PET ligaments. In this study, we immobilized bone morphogenetic protein-2 (BMP-2) on the surface of PET ligaments mediated by polydopamine (PDA) coating and investigated the bioactivation and graft-to-bone healing effect of the modified grafts in vivo and in vitro . Methods: In this study, we prepared the PDA coating and subsequent BMP-2-immobilized PET artificial ligaments. Scanning electron microscopy (SEM) was used to analyze the morphological changes of the modified grafts. In addition, the surface wettability properties of the modified ligaments, amount of immobilized BMP 2, and the release of BMP-2 during a dynamic period up to 28 days were tested. Then, the attachment and proliferation of rat bone mesenchymal stem cells (rBMSCs) on grafts were examined by SEM and Cell Counting Kit-8 (CCK-8) assay, respectively. Alkaline phosphatase (ALP) assay, RT-PCR, and Alizarin Red S staining were performed to test the osteoinduction property. For in vivo experiments, an extra-articular graft-to-bone healing model in rabbits was established. At 8 weeks after surgery, biomechanical tests, micro-CT, and histological staining were performed on harvested samples. Results: A surface morphological analysis verified the success of the PDA coating. The wettability of the PET artificial ligaments was improved, and more than 80% of BMP-2 stably remained on the graft surface for 28 days. The modified grafts could significantly enhance the proliferation, attachment, as well as expression of ALP and osteogenic-related genes, which demonstrated the favorable bioactivity of the grafts immobilized with BMP-2 in vitro . Moreover, the grafts immobilized with BMP-2 at a concentration of 138.4 ± 10.6 ng/cm 2 could highly improve the biomechanical properties, bone regeneration, and healing between grafts and host bone after the implantation into the rabbits compared with the PDA-PET group or the PET group. Conclusion: The immobilization of BMP-2 mediated by polydopamine coating on PET artificial ligament surface could enhance the compatibility and bioactivity of the scaffolds and the graft-to-bone healing in vivo ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kang, Li, Shu, Du, Yu, Qian, Zhong, Zhang, Yu, Huang, Huang, Zhu, Yi and Ding.)

Aims: The aim of this study is to provide a detailed description of cases combining bridging patch repair with artificial ligament "internal brace" reinforcement to treat irreparable massive rotator cuff tears, and report the preliminary results., Methods: This is a retrospective review of patients with irreparable massive rotator cuff tears undergoing fascia lata autograft bridging repair with artificial ligament "internal brace" reinforcement technique between January 2017 and May 2018. Inclusion criteria were: patients treated arthroscopically for an incompletely reparable massive rotator cuff tear (dimension > 5 cm or two tendons fully torn), stage 0 to 4 supraspinatus fatty degeneration on MRI according to the Goutallier grading system, and an intact or reparable infraspinatus and/or subscapularis tendon of radiological classification Hamada 0 to 4. The surgical technique comprised two components: first, superior capsular reconstruction using an artificial ligament as an "internal brace" protective device for a fascia lata patch. The second was fascia lata autograft bridging repair for the torn supraspinatus. In all, 26 patients with a mean age 63.4 years (SD 6.2) were included., Results: All patients underwent more than two years of follow-up (mean 33.5 months (24 to 45)). All clinical scores were also improved at two-year follow-up (mean visual analogue scale 0.7 (SD 0.5) vs 6.1 (SD 1.2); p < 0.001; mean American Shoulder and Elbow Surgeons score 93.5 (SD 5.3) vs 42.5 (SD 10.8); p < 0.001; mean University of California, Los Angeles score, 31.7 (SD 3.7) vs 12.0 (SD 3.1); p < 0.001; and mean Constant-Murley score 88.7 (SD 3.5) vs 43.3 (SD 10.9); p < 0.001), and 24 of 26 fascia lata grafts were fully healed on MRI (92%). One patient had haematoma formation at the harvesting side of the fascia lata at two days postoperatively., Conclusion: The fascia lata autograft bridging repair combined with artificial ligament internal brace reinforcement technique achieved good functional outcomes, with a high rate of graft healing at two-year follow-up. Although the short-term results are promising, further studies with a greater number of patients would provide clearer results. Cite this article: Bone Joint J  2021;103-B(10):1619-1626.

Background: Interference screws are the most common femoral fixation for anterior cruciate ligament (ACL) reconstruction with polyethylene terephthalate (PET) artificial ligaments. However, interference screws have several disadvantages, such as the risk of one tunnel blowout and damage to the graft. Suspensory fixations have the advantages of high tensile strength and promotion of graft bone contact. The purpose of this study was to compare PET artificial ligament graft osseointegration between interference screw fixation (ISF) and cortical suspensory fixation (CSF) for ACL reconstruction., Methods: Forty sheep underwent ACL reconstruction of the right knee with PET artificial ligament. The graft was fixed with ISF or CSF for femoral fixation. Animals were randomly assigned to the ISF (n=20) or the CSF (n=20) groups. The sheep were sacrificed at 3 or 12 months postoperatively for biomechanical tests, micro computed tomography (micro-CT) scans, and histological assessments., Results: The mean load-to-failure between the CSF group (836±355 N) appeared higher than that of the ISF group (604±277 N) at 3 months, but no significant difference was detected between the groups (P=0.24). At 12 months, there was also no significant difference in load-to-failure between the CSF and ISF groups (1,194±350 vs. 1,097±764 N; P=0.78). According to the micro-CT scan results, the femoral bone tunnel diameter of the ISF group appeared larger than that of the CSF group at 3 months (12±1 vs. 10±1 mm; P=0.02) and similar to that of the CSF group at 12 months (12±1 vs. 11±2 mm; P=0.38). Furthermore, histological results showed that at the graft-tunnel interface of the femoral tunnel aperture, disoriented fibers formed in the ISF group while oriented and dense fibers formed in the CSF group., Conclusions: ACLR with synthetic ligament by cortical suspension devices with adjustable loops demonstrated a better graft-bone healing capacity at the femoral tunnel aperture compared with that from titanium interference screws over 12 months postoperatively. No significant difference was found in biomechanical strength between the two fixation methods during the early healing stage., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://dx.doi.org/10.21037/atm-21-1076). The authors declare that they have no competing interests., (2021 Annals of Translational Medicine. All rights reserved.)

Abstract: The aims of this study were to analyze the preliminary clinical outcome of limb salvage using Ligament Advanced Reinforcement System (LARS). It is hypothesized that LARS ligament is a safe and effective choice to enhance prosthetic reconstructions, providing good muscles reattachment and improving joint stability. From March 2009 to March 2010, 7 patients received megaprosthesis reconstruction following tumor resection in combination with soft tissue reconstruction using LARS. Reconstructions were four around the knee and three in proximal femur. The average MSTS 93 score was 81.0% at a mean follow-up of 27.0 months. No infection was observed. The results show that LARS appears to be an effective device for limb salvage surgery providing good muscles reattachment, improving joint stability. [Copyright &y& Elsevier]

Background: Despite the advantages of excellent mechanical properties for rapid return to sports and early rehabilitation after anterior cruciate ligament (ACL) reconstruction with polyethylene terephthalate (PET) artificial ligament, the graft failure rate during long-term follow-up is relatively high due to poor graft-host incorporation. The purpose of the present study was to investigate the effect of autologous tissue-engineered PET (ATE-PET) grafts on osseointegration and ligamentization after ACL reconstruction., Methods: Forty-eight New Zealand white rabbits were randomly divided into PET group (n=24) and ATE-PET group (n=24). In the ATE-PET group, the rabbits initially underwent subcutaneous implantation of the PET ligament. Two weeks later, unilateral ipsilateral ACL reconstruction was performed using an ATE-PET graft. In the PET group, the rabbits underwent ACL reconstruction using PET grafts as controls. Macroscopic observation, micro-computed tomography, histological and immunofluorescent staining, and biomechanical tests were conducted to evaluate the effects at 4 and 12 weeks postoperatively., Results: The ATE-PET graft was highly pre-vascularized with myofibroblast aggregation after two weeks of subcutaneous implantation. With regard to the intraosseous part of the graft, the ATE-PET group had significantly higher bone mineral density and bone volume/total volume ratio at 12 weeks. Histologically, the width of the interface between the graft and bone was smaller. Regarding the intra-articular part, thicker tissue coverage with a glossy appearance was observed in the ATE-PET group at 12 weeks on macroscopic observation. Histological staining also showed more collagen fibers grew in the grafts with fewer inflammatory reactions of the ATE-PET group at both 4 and 12 weeks. Immunofluorescently, both α-SMA-positive vessels and α-SMA-positive myofibroblasts were found to be significantly greater around the graft in the ATE-PET group at 4 weeks and markedly declined at 12 weeks. Moreover, the ATE-PET group presented significantly greater failure load and stiffness than the PET group at 12 weeks (53.7±5.4 vs. 42.5±4.5 N, P<0.01; 12.9±3.0 vs. 9.8±1.3 N/mm, P=0.04)., Conclusions: The ATE-PET artificial ligament with pre-vascularization and myofibroblast aggregation could effectively accelerate intra-articular graft ligamentization and intraosseous graft osseointegration, thus enhancing the biomechanical properties after ACL reconstruction in a rabbit model., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/atm-20-8048). The authors have no conflicts of interest to declare., (2021 Annals of Translational Medicine. All rights reserved.)

Due to its great biomechanical property, the polyethylene terephthalate (PET) artificial ligament has become one of the most promising allografts for anterior cruciate ligament (ACL) reconstruction. However, because of its chemical and biological inertness, PET is not a favored scaffold material for osteoblast growth, which promotes the ligament-bone healing. Meanwhile, in consideration of prevention of potential infection, the prophylactic injection of antibiotic was used as a post-operative standard procedure but also has the increasing risk of bacterial resistance. To face these two contradictions, in this article we coated a polydopamine (PDA) nano-layer on the PET ligament and used the coating as the adhesion interlayer to introduce nano-hydroxyapatite (nHA) and silver atoms to the surface of PET ligament. Because of the mild self-polymerization reaction of dopamine, the thermogravity analysis (TGA), Raman spectrum, and tensile test results show that the modification procedure have no negative effects on the chemical stability and mechanical properties of the PET. The results of NIH3T3 cell culture show that the PDA and nHA could effectively improve the biocompatibility of PET artificial ligament for fibroblast growth, and staphylococcus aureus antibacterial test results show that the Ag atom provided an antibacterial effect for PET ligament. As shown in this paper, the nano-PDA coating modification procedure could not only preserve the advantages of PET but also introduce new performance characteristics to PET, which opens the door for further functionalization of PET artificial ligament for its advanced development and application., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wu, Zhang, Zhang and Chen.)

Dual-mobility and constrained cups can stabilise most recurrent dislocations of total hip arthroplasty (THA), but may fail in case of hip abductor mechanism loss. For such complex situations, we developed an original artificial iliofemoral and ischiofemoral ligament reconstruction technique using a polyglactin 910 mesh (Vicryl ™) associated to repositioning of a Lefèvre constrained liner adapted to hip range of motion to prevent cam effects. The technique was implemented in 2 patients showing recurrent dislocation after THA, associating total femur replacement and cemented constrained liner in a metal reinforcement ring. In one of the 2 cases, the abductor mechanism had been entirely sacrificed. This simple and accessible salvage technique prevented recurrence of dislocation at 12 months' follow-up in these complex cases, previously subject to several episodes per year., (Copyright © 2020. Published by Elsevier Masson SAS.)