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Background: Research on return to sport and psychological recovery in anterior cruciate ligament (ACL) revision remains scarce. The clinical efficacy of artificial ligament in ACL revision requires further exploration. Our objectives were (1) to compare the midterm clinical outcomes of artificial ligament versus allogenic tendon graft in ACL revision and (2) to analyze the effects of employing artificial ligament on return to sport and psychological recovery in ACL revision. Methods: This cohort study included the cases receiving ACL revision from 2014 to 2021 in Sports Medicine Department of Huashan Hospital. The grafts used were Ligament Advanced Reinforcement System (LARS) and ATT allograft. We recorded patients' baseline data. The final follow-up assessment included subjective scales, physical examination, and return to sport status. We recorded the rates and timings of return to sport. Subjective scales included the 2000 International Knee Documentation Committee (IKDC) subjective score, Lysholm Knee Scaling Score (LKSS), Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner activity score, Marx activity rating score, and Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI). Anterior knee stability was assessed using the KT-1000 arthrometer. Results: Fifty cases (LARS group: 27; ATT group: 23) enrolled and 45 (LARS group: 23; ATT group: 22) completed evaluations with a median follow-up period of 49 months. At recent follow-up, LARS group outperformed in knee stability (1.0 ± 1.9 mm vs. 2.6 ± 3.0 mm, P = 0.039), confidence (86.7 ± 12.4 vs. 69.4 ± 18.6, P

Artificial ligaments transplanted into the human body are subject to ligament rupture and ligament fatigue injury during exercise. The three-section structure of artificial ligaments has a tight structure which can improve the breaking strength at the two ends, and a looser structure which can keep the flexibility in the middle. At present, scholars have studied braided artificial ligaments with high elasticity and creep resistance, and three-section artificial ligaments have other advantages on this basis. In this study, the three-section artificial ligaments were braided with UHMWPE, and a core-shell structure was used at both ends of the ligament as a way to strengthen the tightness and strength, facilitate the fixation of the ligament, and improve the fatigue resistance of artificial ligaments. In addition, the mechanical properties of artificial ligaments were investigated with different numbers of cores. This study proved that the three-section artificial ligament, which is made of UHMWPE has high strength, excellent elastic recovery rate, and fatigue resistance, which can provide mechanical support for the daily activities of the knee joint and help maintain the stability of the knee joint. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the results of Gant-Miwa-Thiersch (GMT) rectal prolapse repair using an artificial ligament in elderly patients. Subjects and Methods: We investigated the perioperative and postoperative outcomes of 35 patients aged 85 years or older with rectal prolapse who underwent radical surgery at our hospital from January 2012 to December 2022. Results: The median age of the patients was 88 years, and all were female. The median length of bowel evacuation was 7 cm, and the median operative time was 37 minutes. There was one perioperative complication including infection of the artificial ligament. There was two cases of recurrence, but neither recurrence occurred after additional transperineal surgery. Fecal incontinence was present preoperatively in 23 patients, but improved postoperatively in 11. Constipation was well controlled with oral medication, and there were no cases of long-term difficulty of defecation. Conclusion: GMT using an artificial ligament may be the first choice for rectal prolapse repair in very elderly patients. [ABSTRACT FROM AUTHOR]

A 65-year-old woman presented with right elbow pain after a fall. Imaging showed an avulsion fracture of the olecranon. The patient subsequently underwent surgery using the suture bridge technique with anchors. However, loosening was observed intraoperatively. Therefore, a McLaughlin cerclage with an artificial ligament was added, resulting in a rigid fixation. Bone union was achieved at 4 months postoperatively. At 18 months postoperatively, no limitation was observed in the range of motion of the elbow joint; the disabilities of the arm, shoulder and hand score was 0. McLaughlin cerclage with an artificial ligament provided additional fixation, demonstrating greater strength compared with suture anchors and minimizing the risk of cut-through in the osteoporotic bone. This approach offers a promising alternative for such cases by combining firm fixation with a reduced risk of complications, particularly in older patients with osteoporosis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Grafts are often used to reconstruct the anterior cruciate ligament in clinical practice, while different types of grafts affect postoperative knee function and the development of rehabilitation programs. OBJECTIVE: To retrospectively analyze the effects of different graft types on muscle strength, joint stability, functional activities, and return to sports in patients after anterior cruciate ligament reconstruction. METHODS: Related studies were searched through PubMed, Web of Science, Cochrane, CNKI, and WANFANG databases. The Chinese and English key words were “anterior cruciate ligament reconstruction, autografts, allografts, artificial ligaments, bone-patellatendon-bone, quadriceps tendon autograft, hamstring tendon autograft, peroneus longus tendon autograft, rehabilitation, exercise, protocol, return to sport”. RESULTS AND CONCLUSION: Patients with bone-patellar tendon-bone grafts should strengthen centrifugal contraction exercises of quadriceps muscle, and pay attention to the recovery of quadriceps muscle endurance and explosive power in the later stage of rehabilitation. Compared with bone-patellar tendon-bone grafts and hamstring tendon grafts, significantly fewer patients with quadriceps tendon grafts met regression criteria within 5-8 months, and a longer training plan should be developed, with the training cycle lasting as long as possible to more than 3 years. The selection of hamstring tendon grafts should strengthen the hamstring muscle strength training under multiple angles, especially the cycle of bending the knee above 60° until at least 18 weeks after surgery. Patients who choose peroneus longus tendon graft should strengthen the muscle strength around the ankle, mainly the plantar muscle strength. In the selection of allograft, attention should be paid to the reduction of tension resistance of 20% after the graft is disinfected by low-dose radiation, so attention should be paid to knee stability training. Patients who choose artificial ligament grafts can gradually enhance quadriceps and hamstring muscle strength training within 3-6 weeks, pay attention to early proprioceptive exercises, and conduct targeted training on balance, jumping, and flexibility. [ABSTRACT FROM AUTHOR]

Artificial ligament products exhibit various drawbacks in clinical applications, including non-degradability, stress shielding, mid-to long-term fatigue relaxation, and chronic inflammation. Therefore, the development of biodegradable artificial ligament materials with excellent mechanical properties represents the future direction of new-generation artificial ligaments. In the present study, an artificial ligament (AL) prototype with "shell-core" structure was designed through the use of silk fibroin fibers as raw materials, and AL was coated with polyurethane(PU) solution mixed with nanohydroxyapatite( Hap) to obtain coated artificial ligament (CAL) materials. Furthermore, morphology, microstructure, mechanical properties, degradability, cell and tissue compatibility of the CAL were systematically characterized. The results demonstrate a regular "shell-core" structure, smooth surface, and uniform pores. Compared to AL, the mechanical properties of the CAL were significantly improved(P<0.05), and the degradation rate in vitro was significantly delayed. Furthermore, the results of cell and tissue compatibility tests indicate that the CAL exhibits satisfactory cell and tissue compatibility, and mild inflammatory reaction. This study provides a theoretical basis and practical reference for development of new high-strength biodegradable artificial ligament products. [ABSTRACT FROM AUTHOR]

Inspired by “crimped” collagen fiber, which induce a low-level load region within the hierarchical structures of ligaments and tendons, this study introduces a braiding technology aiming at characterizing nonlinear mechanical behavior. Samples of the developed artificial ligament with a multilayer braided structure were fabricated and tested. Alterations in the number of braiding layers, wales, and courses significantly affect the mechanical properties of the artificial ligaments. Specifically, the toe length exhibited an increase of up to 104.58 %, while the linear stiffness exhibited variations concomitant with changes in these parameters. Additionally, a mathematical model to describe the relationship between the toe length and linear stiffness was developed based on the braiding parameters and material properties of the fibers. Alternative fibers were employed and tested to demonstrate a consistency with the mathematical model. The correlation coefficients were calculated as 0.9644 for the toe length and 0.9203 for the linear stiffness. Lastly, this study mimics the mechanical behavior of the human medial collateral ligament (MCL) by integrating the artificial ligament into a bio-fidelity knee model with a joint stiffness of 1.77 Nm/deg, resulting in a high degree of similarity with human knee in valgus-varus, further affirming the utility and applicability of this study.

Abstract Background To compare proprioception recovery after anterior cruciate ligament reconstruction (ACLR) with a hamstring tendon autograft versus the artificial Ligament Advanced Reinforcement System (LARS). Material and methods Forty patients (9 females, 31 males) with anterior cruciate ligament (ACL) rupture were enrolled in this prospective study. Patients were randomized to two groups, 1) ACLR using a hamstring tendon autograft (n = 20) or 2) ACLR using artificial LARS (n = 20). Proprioception was assessed with knee joint position sense (JPS) passive-passive test at 45° and 75° flexions, with the contralateral healthy knee as a control baseline to calculate the JPS error. Knee JPS absolute error was used as the main outcome variable and defined as the absolute difference between the reproduction and target angles. Results JPS error in both groups at 3 months after ACLR was significantly higher than that at 12 months. However, no significant difference in JPS error was detected between the LARS and autograft groups at either 3 or 12 months after ACLR. Analyzing JPS data by grouping patients according to whether ACLR was performed more or less than 1 year following injury regardless of graft type showed a statistically significant difference between the groups at 3 months, but not at 12 months, after ACLR. Patients receiving the graft within 1 year of injury had a lower JPS error than those receiving the graft more than 1 year after injury at 3 months. No complications were associated with either ACLR method. Conclusion ACLR with a hamstring tendon autograft or LARS artificial graft is similarly safe and effective for recovering knee proprioception.

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.

Objective To explore the surgical treatment of the modified Broström procedure augmented with suturetape repair of anterior talofibular ligament using mini-open incision. Methods A tatal of 17 patients with chronic lateral ankle instability underwent the modified Broström procedure augmented with suture-tape reconstruction of anterior talofibular ligament using mini-open incision. The patients included 11 males and 6 females, aged 28-56 years with a mean of (40.20±13.75) years. Body mass index (BMI) was 30.12-35.10 kg/m² with a mean of (32.27±1.83) kg/m². The FAOS and FAAM were used to evaluate the postoperative function of ankle. Results All patients had operation performed smoothly, without serious complications, and got incisions healed well. All 17 patients were followed up for 12-24 months. Compared with those preoperative, the FAOS (from 57.10±11.32 to 91.35±1.27, P＜0.05) and FAAM (from 55.76±10.12 to 91.10±0.69, P＜0.05) scores significantly improved at the latest follow-up and no complications, such as nerve, blood vessel and tendon injury. Two patients experienced tightness in the lateral ankle during early walking, and the symptoms were resolved after 8 weeks. Conclusion For the chronic lateral ankle instability, the modified Broström procedure augmented with suture-tape repair of anterior talofibular ligament using mini-open incision effectively reduces symptoms and get early rehabilitation, with definite effect. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) artificial ligaments offer an unlimited source of ligaments without donor-site-related morbidity and with good mechanical properties for a rapid return to sporting activities. Developing PET artificial ligaments with excellent ligamentisation and ligament-bone healing is still a considerable challenge. This study aimed to investigate the effects of the profiled PET/collagen/calcium phosphate (PET/C/CaP) ligament upon cell growth, ligamentisation and ligament-bone healing in vitro and in vivo. Profiled PET/C/CaP filaments were made by melt-spinning process with 2 % CaP hybrid spinning and collagen coating. Rat mesenchymal stem cells (MSCs) were cultured on the profiled PET/C filaments for cytotoxicity, viability, scanning electron microscopy (SEM) and ligament-related gene expression analysis. MSCs’ osteogenic capacity on the profiled PET/CaP filaments was identified by detecting osteogenic gene expression and alizarin red S staining. For in vivo verification, an animal study was performed to evaluate the effect of the profiled PET/C/CaP ligament in a rabbit knee medial collateral ligament reinforcement reconstruction model. The graft ligamentisation and bone formation were investigated by SEM, histology, microcomputed tomography and mechanical tests. The profiled PET/C filaments enhanced MSC proliferation and ligament-related gene expression. Furthermore, they enhanced osteogenic gene expression, alkaline phosphatase activity and mineralisation of MSCs. The in vivo study indicated that the profiled PET/C/CaP ligament enhanced ligamentous matrix remodelling and bone formation. Therefore, their use is an effective strategy for promoting MSCs’ ligamentous and osteogenic potential in vitro and enhancing ligamentous matrix remodelling and bone formation in vivo.

Implant infection impairs osseointegration of orthopaedic implants by inducing inflammation. Acinetobacter spp. are increasingly prevalent multi-drug resistant bacteria that can cause osteomyelitis. Acinetobacter spp. can also cause inflammation and thereby inhibit osseointegration in mice. The purpose of the present study was to investigate the role of quorum sensing in this context. Therefore, wild-type bacteria were compared with an isogenic abaI mutant defective in quorum sensing in a murine osseointegration model. The abaI quorum- sensing mutant affected significantly less osseointegration and interleukin (IL) 1β levels, without detectably altering other pro-inflammatory cytokines. Wild-type bacteria had fewer effects on IL1 receptor (IL1R)−/− mice. These results indicated that quorum sensing in Acinetobacter spp. contributed to IL1β induction and the resultant inhibition of osseointegration in mice. Moreover, targeting the Gram-negative acyl-homoserine lactone quorum sensing may be particularly effective for patients with Acinetobacter spp. infections.

Background: To compare proprioception recovery after anterior cruciate ligament reconstruction (ACLR) with a hamstring tendon autograft versus the artificial Ligament Advanced Reinforcement System (LARS). Material and methods: Forty patients (9 females, 31 males) with anterior cruciate ligament (ACL) rupture were enrolled in this prospective study. Patients were randomized to two groups, 1) ACLR using a hamstring tendon autograft (n = 20) or 2) ACLR using artificial LARS (n = 20). Proprioception was assessed with knee joint position sense (JPS) passive-passive test at 45° and 75° flexions, with the contralateral healthy knee as a control baseline to calculate the JPS error. Knee JPS absolute error was used as the main outcome variable and defined as the absolute difference between the reproduction and target angles. Results: JPS error in both groups at 3 months after ACLR was significantly higher than that at 12 months. However, no significant difference in JPS error was detected between the LARS and autograft groups at either 3 or 12 months after ACLR. Analyzing JPS data by grouping patients according to whether ACLR was performed more or less than 1 year following injury regardless of graft type showed a statistically significant difference between the groups at 3 months, but not at 12 months, after ACLR. Patients receiving the graft within 1 year of injury had a lower JPS error than those receiving the graft more than 1 year after injury at 3 months. No complications were associated with either ACLR method. Conclusion: ACLR with a hamstring tendon autograft or LARS artificial graft is similarly safe and effective for recovering knee proprioception. [ABSTRACT FROM AUTHOR]

The anterior cruciate ligament is one of the important tissues to maintain the stability of the human knee joint, but it is difficult for this ligament to self-heal after injury. Consequently, transplantation of artificial ligaments (ALs) has gained widespread attention as an important alternative treatment method in recent years. However, accurately predicting the intricate mechanical properties of ALs remains a formidable challenge, particularly when employing theoretical frameworks such as braiding theory. This obstacle presents a significant impediment to achieving optimal AL design. Therefore, in this study, a high-precision machine learning model based on an artificial neural network was developed to rapidly and accurately predict the mechanical properties of ALs. The results showed that the proposed model achieved a reduction of 45.22% and 50.17% in the normalized root mean square error on the testing set when compared to traditional machine learning models (Random Forest and Support Vector Machine), demonstrating its higher accuracy. In addition, the design of ALs with desired mechanical properties was achieved by optimizing the braiding parameters, and its effectiveness was verified through experiments. The mechanical properties of the prepared ALs were able to fully meet the desired targets and were at least 2% higher. Finally, the influence weights of different braiding parameters on the mechanical properties of ALs were analyzed by feature importance. [ABSTRACT FROM AUTHOR]

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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.

It is a big challenge to develop a polyethylene terephthalate (PET) artificial ligament with excellent osteogenetic activity to enhance graft-bone integration for ligament reconstruction. Herein, we evaluated the effect of biomineralization (BM) and electrodeposition (ED) method for depositing calcium-phosphate (CaP) on the PET artificial ligament in vitro and in vivo. Scanning electron microscopy and energy-dispersive X-Ray spectrometer mapping analysis revealed that the ED-CaP had more uniform particles and element distribution (Ca, P and O), and thermogravimetric analysis showed there were more CaP on the PET/ED-CaP than the PET/BM-CaP scaffold. Moreover, the hydrophilicity of PET scaffolds was significantly improved after CaP deposition. In vitro study showed that CaP coating via BM or ED method could improve the attachment and proliferation of MC3T3-E1 cells, and ED-CaP coating significantly increased osteogenic differentiation of the cells, in which the Wnt/β-catenin signaling pathway might be involved. In addition, radiological, histological and immunohistochemical results of in vivo study in a rabbit anterior cruciate ligament (ACL) reconstruction model demonstrated that the PET/BM-CaP and PET/ED-CaP scaffolds significantly improved graft-bone integration process compared to the PET scaffold. More importantly, larger areas of new bone ingrowth and the formation of fibrocartilage tissue were observed at 12 weeks in the PET/ED-CaP group, and the biomechanical tests showed increased ultimate failure load and stiffness in PET/ED-CaP group compared to PET/BM-CaP and PET group. Therefore, ED of CaP is an effective strategy for the modification of PET artificial ligament and can enhance graft-bone integration both in vitro and in vivo.

Control over soft‐to‐hard tissue interfaces is attracting intensive worldwide research efforts. Herein, a bioactive film‐guided soft–hard interface design (SHID) for multi‐tissue integrative regeneration is shown. Briefly, a soft bioactive film with good elasticity matchable to native ligament tissue, is incorporated with bone‐mimic components (calcium phosphate cement, CPC) to partially endow the soft‐film with hard‐tissue mimicking feature. The hybrid film is elegantly compounded with a clinical artificial ligament to act as a buffer zone to bridge the soft (ligament) and hard tissues (bone). Moreover, the bioactive film‐decorated ligament can be rolled into a 3D bio‐instructive implant with spatial‐controllable distribution of CPC bioactive motifs. CPC then promotes the recruitment and differentiation of endogenous cells in to the implant inside part, which enables a vascularized bone growth into the implant, and forms a structure mimicking the biological ligament–bone interface, thereby significantly improving osteointegration and biomechanical property. Thus, this special design provides an effective SHID‐guided implant‐bioactivation strategy unreached by the traditional manufacturing methods, enlightening a promising technology to develop an ideal SHID for translational use in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Arthroscopic reconstruction of posterior cruciate ligament has become the main treatment for severe injury of posterior cruciate ligament. Mastering the characteristics of all kinds of posterior cruciate ligament reconstruction grafts and selecting suitable transplantation materials are considered to be an important link affecting the effect of posterior cruciate ligament reconstruction. OBJECTIVE: To summarize the advantages and disadvantages of autografts, allografts and artificial ligaments in posterior cruciate ligament reconstruction, and put forward improvement strategies and prospect. METHODS: The first author searched the articles about implant materials (autografts, allografts and artificial ligaments) for the reconstruction of posterior cruciate ligament on PubMed database, CNKI database and Wanfang database from 2000 to 2020. The articles obtained in accordance with the search words were screened and retained, and the relevant articles related to the analysis of the advantages and disadvantages of all kinds of posterior cruciate ligament grafts were further analyzed and summarized in detail. RESULTS AND CONCLUSION: Posterior cruciate ligament reconstruction grafts have their own advantages and disadvantages. At present, autogenous hamstring tendon grafts are most widely used in clinic. Ligament enhancement device, internal tension reduction technique or tendon surface coating technology can improve the effect of posterior cruciate ligament reconstruction. Autogenous tendons, allogeneic tendons and artificial ligaments are all important sources of posterior cruciate ligament reconstruction grafts in the short term. With the progress of artificial ligament and tissue engineering ligament research in the long term, it is expected to completely solve the problem of posterior cruciate ligament reconstruction materials. When selecting posterior cruciate ligament grafts, surgeon should consider the level of activity expected by patients, the types of activities they participate in, their professional characteristics, the reconstruction techniques and habits mastered by doctors, and the fixed materials matched with the grafts, so as to select a suitable posterior cruciate ligament reconstruction graft. [ABSTRACT FROM AUTHOR]

Background: As many researchers have focused on promoting the graft-bone healing of artificial ligaments, even with numerous chemical coatings, identifying a biosafe, effective, and immediately usable method is still important clinically. Purpose: (1) To determine whether a low-intensity pulsed ultrasound system (LIPUS) promotes in vitro cell viability and osteogenic differentiation and (2) to assess the applicability and effectiveness of LIPUS in promoting the graft-bone healing of artificial ligaments in vivo. Study Design: Controlled laboratory study. Methods: Polyethylene terephthalate (PET) sheets and grafts were randomly assigned to control and LIPUS groups. MC3T3-E1 preosteoblasts were cultured on PET sheets. Cell viability and morphology were evaluated using a live/dead viability assay and scanning electron microscopy. Alkaline phosphatase activity, calcium nodule formation, and Western blot were evaluated for osteogenic differentiation. For in vivo experiments, the effect of LIPUS was evaluated via an extra-articular graft-bone healing model in 48 rabbits: the osteointegration and new bone formation were tested by micro–computed tomography and histological staining, and the graft-bone bonding was tested by biomechanical testing. Results: Cell viability was significantly higher in the LIPUS group as compared with control (living and dead compared between control and LIPUS groups, P =.0489 vs P =.0489). Better adherence of cells and greater development of extracellular matrix were observed in the LIPUS group. Furthermore, LIPUS promoted alkaline phosphatase activity, calcium nodule formation, and the protein expression of collagen 1 (P =.0002) and osteocalcin (P =.0006) in vitro. Micro–computed tomography revealed higher surrounding bone mass at 4 weeks and newly formed bone mass at 8 weeks in the LIPUS group (P =.0014 and P =.0018). Histological analysis showed a narrower interface and direct graft-bone contact in the LIPUS group; the surrounding bone area at 4 weeks and the mass of newly formed bone at 4 and 8 weeks in the LIPUS group were also significantly higher as compared with control (surrounding bone, P <.0001; newly formed bone, P =.0016 at 4 weeks and P =.005 at 8 weeks). The ultimate failure load in the LIPUS group was significantly higher than in the control group (P <.0001 at 4 weeks; P =.0008 at 8 weeks). Conclusion: LIPUS promoted the viability and osteogenic differentiation of MC3T3-E1 preosteoblasts in vitro and enhanced the graft-bone healing of PET artificial ligament in vivo. Clinical Relevance: LIPUS is an effective physical stimulation to enhance graft-bone healing after artificial ligament implantation. [ABSTRACT FROM AUTHOR]

Abstract Control over soft‐to‐hard tissue interfaces is attracting intensive worldwide research efforts. Herein, a bioactive film‐guided soft–hard interface design (SHID) for multi‐tissue integrative regeneration is shown. Briefly, a soft bioactive film with good elasticity matchable to native ligament tissue, is incorporated with bone‐mimic components (calcium phosphate cement, CPC) to partially endow the soft‐film with hard‐tissue mimicking feature. The hybrid film is elegantly compounded with a clinical artificial ligament to act as a buffer zone to bridge the soft (ligament) and hard tissues (bone). Moreover, the bioactive film‐decorated ligament can be rolled into a 3D bio‐instructive implant with spatial‐controllable distribution of CPC bioactive motifs. CPC then promotes the recruitment and differentiation of endogenous cells in to the implant inside part, which enables a vascularized bone growth into the implant, and forms a structure mimicking the biological ligament–bone interface, thereby significantly improving osteointegration and biomechanical property. Thus, this special design provides an effective SHID‐guided implant‐bioactivation strategy unreached by the traditional manufacturing methods, enlightening a promising technology to develop an ideal SHID for translational use in the future.

An artificial ligament tensile and torsion fatigue testing device was designed aiming at the implant failure of artificial ligaments due to stretching and torsion in vivo. The device was composed of a computer, a fabric strength tester, a mechanical sensor, an upper clamping device and a torsion fatigue device component that simulates the shear load of the anterior cruciate ligament of the human body. Two self-made artificial ligaments with braiding structures were used for tensile and torsion fatigue testing to verify the feasibility of the device. The results indicate that the apparent morphology of the artificial ligament is partially altered after fatigue loading and that fiber dislocation due to the torsional shear loading may cause postoperative complications, in addition to a loss of tensile and elastic recovery properties of the artificial ligament. The device has good simulation and testing stability, which can provide guidance for the research and development, industrialization and clinical use of the artificial ligament. [ABSTRACT FROM AUTHOR]

The development of an artificial ligament with a multifunction of promoting bone formation, inhibiting bone resorption, and preventing infection to obtain ligament-bone healing for anterior cruciate ligament (ACL) reconstruction still faces enormous challenges. Herein, a novel artificial ligament based on a PI fiber woven fabric (PIF) was fabricated, which was coated with a phytic acid-gallium (PA-Ga) network via a layer-by-layer assembly method (PFPG). Compared with PIF, PFPG with PA-Ga coating significantly suppressed osteoclastic differentiation, while it boosted osteoblastic differentiation in vitro . Moreover, PFPG obviously inhibited fibrous encapsulation and bone absorption while accelerating new bone regeneration for ligament-bone healing in vivo . PFPG remarkably killed bacteria and destroyed biofilm, exhibiting excellent antibacterial properties in vitro as well as anti-infection ability in vivo , which were ascribed to the release of Ga ions from the PA-Ga coating. The cooperative effect of the surface characteristics ( e.g. , hydrophilicity/surface energy and protein absorption) and sustained release of Ga ions for PFPG significantly enhanced osteogenesis while inhibiting osteoclastogenesis, thereby achieving ligament-bone integration as well as resistance to infection. In summary, PFPG remarkably facilitated osteoblastic differentiation, while it suppressed osteoclastic differentiation, thereby inhibiting osteoclastogenesis for bone absorption while accelerating osteogenesis for ligament-bone healing. As a novel artificial ligament, PFPG represented an appealing option for graft selection in ACL reconstruction and displayed considerable promise for application in clinics.

Background: Research on return to sport and psychological recovery in anterior cruciate ligament (ACL) revision remains scarce. The clinical efficacy of artificial ligament in ACL revision requires further exploration. Our objectives were (1) to compare the midterm clinical outcomes of artificial ligament versus allogenic tendon graft in ACL revision and (2) to analyze the effects of employing artificial ligament on return to sport and psychological recovery in ACL revision., Methods: This cohort study included the cases receiving ACL revision from 2014 to 2021 in Sports Medicine Department of Huashan Hospital. The grafts used were Ligament Advanced Reinforcement System (LARS) and ATT allograft. We recorded patients' baseline data. The final follow-up assessment included subjective scales, physical examination, and return to sport status. We recorded the rates and timings of return to sport. Subjective scales included the 2000 International Knee Documentation Committee (IKDC) subjective score, Lysholm Knee Scaling Score (LKSS), Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner activity score, Marx activity rating score, and Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI). Anterior knee stability was assessed using the KT-1000 arthrometer., Results: Fifty cases (LARS group: 27; ATT group: 23) enrolled and 45 (LARS group: 23; ATT group: 22) completed evaluations with a median follow-up period of 49 months. At recent follow-up, LARS group outperformed in knee stability (1.0 ± 1.9 mm vs. 2.6 ± 3.0 mm, P = 0.039), confidence (86.7 ± 12.4 vs. 69.4 ± 18.6, P < 0.001), emotion (82.7 ± 11.3 vs. 70.7 ± 16.2, P < 0.001), KOOS knee function (78.7 ± 8.8 vs. 69.5 ± 11.0, P = 0.003), quality of life (79.1 ± 16.1 vs. 66.4 ± 19.5, P = 0.014), Tegner score (6.3 ± 1.9 vs. 5.2 ± 2.1, P < 0.001), and Marx activity score (10.7 ± 3.7 vs. 7.9 ± 4.0, P = 0.012). The LARS group had significantly higher return rates: recreational (91.3 % vs. 63.6 %, P = 0.026), knee cutting and pivoting (87.0 % vs. 59.1 %, P = 0.035), competitive (78.3 % vs. 45.5 %, P = 0.023), and pre-injury (56.5 % vs. 27.3 %, P = 0.047). For return timings, the LARS group was earlier at recreational (11.2 ± 3.9 vs. 27.8 ± 9.0 weeks, P < 0.001), knee cutting and pivoting (17.2 ± 5.8 vs. 35.6 ± 13.8 weeks, P < 0.001), competitive (24.8 ± 16.2 vs. 53.2 ± 22.0 weeks, P < 0.001), and pre-injury levels (32.8 ± 11.0 vs. 72.8 ± 16.9 weeks, P < 0.001)., Conclusion: In ACL revision, using LARS demonstrated improved joint stability and functionality compared to using allogenic ATT four years postoperative. Patients accepting the LARS procedure exhibited higher rates and earlier timings of return to various levels of sport, indicating enhanced confidence and emotional resilience., The Translational Potential of This Article: In ACL revision, the choice of artificial ligament to shorten recovery time, thereby enabling patients to return to sport more quickly and effectively, is thought-provoking. The research value extends beyond mere graft selection, guiding future clinical trials and studies. This research enhances our understanding of the application value of artificial ligament in ACL revision, emphasizing the importance of psychological recovery and updating our perceptions of return to sport levels post-revision. It stimulates exploration into personalized rehabilitation programs and treatment strategies, aiming to optimize clinical outcomes and meet the real-world needs of patients with failed ACL reconstruction., Competing Interests: All authors wish to declare that there are no conflicts of interest regarding the publication of this paper, particularly in relation to the use of Ligament Advanced Reinforcement System (LARS) and allograft tendons. None of the authors have any financial or personal relationships with the companies or organizations that manufacture or distribute these materials that could inappropriately influence or bias the content and findings of this manuscript. This research was conducted independently and did not receive specific funding from any agencies in the public, commercial, or not-for-profit sectors related to LARS or allograft tendon products. This research was supported by the General Program of the National Natural Science Foundation of China (Grant No. 82172511)., (© 2024 Published by Elsevier B.V. on behalf of Chinese Speaking Orthopaedic Society.)

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/cm2 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.

BACKGROUND: Irregular structures on the nanometer scale mimic the structure of natural extracellular matrix molecules, and can be used as a carrier for cell adhesion or proliferation to promote tissue regeneration at the site of implantation. OBJECTIVE: To review the research progress of nanomaterial artificial ligament applied in ligament reconstruction. METHODS: Computer was used to search CNKI, PubMed, Web of Science, Embase, Cqvip and Wanfang databases. The search terms were “tissue engineering, nanomaterials, artificial ligaments, nanometre, nanoscale, artificial ligament”. According to the standard, the research progress of nanomaterial artificial ligament was included in the literature. RESULTS AND CONCLUSION: Nanomaterials have good biological compatibility. Artificial ligaments modified by nanomaterials can provide good adhesion environment for cells and promote cell proliferation. Bone marrow mesenchymal stem cells can proliferate and differentiate on the surface of artificial ligaments modified by nanomaterials and promote the extension of bone into ligaments. This effect enhances the strength of ligaments and promotes tendon and bone healing to a certain extent. Nanomaterial scaffold is a promising solution for the treatment of ligament injuries. The current nanofiber preparation technology has laid the foundation for the implementation of this solution. Currently, the prepared nanofibers can provide ideal mechanical strength, and some nanomaterials are degradable. After implantation, they can promote the proliferation of fibroblasts and gradually replace the nanofibers until ligament regeneration is achieved. The research of nanomaterial scaffold has also made some progress in bone connection and anti-adhesion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical structures of ligaments lead to the non-linear mechanical properties. • Reproduction of non-linear mechanical properties by a multilayer braided structure. • Braiding parameters and multiplayer structure were described by a mathematic model. • Controllable braiding parameters characterizes various biological tissues. • The correlation coefficient between the human and artificial ligaments was 0.9985. Inspired by "crimped" collagen fiber, which induce a low-level load region within the hierarchical structures of ligaments and tendons, this study introduces a braiding technology aiming at characterizing nonlinear mechanical behavior. Samples of the developed artificial ligament with a multilayer braided structure were fabricated and tested. Alterations in the number of braiding layers, wales, and courses significantly affect the mechanical properties of the artificial ligaments. Specifically, the toe length exhibited an increase of up to 104.58 %, while the linear stiffness exhibited variations concomitant with changes in these parameters. Additionally, a mathematical model to describe the relationship between the toe length and linear stiffness was developed based on the braiding parameters and material properties of the fibers. Alternative fibers were employed and tested to demonstrate a consistency with the mathematical model. The correlation coefficients were calculated as 0.9644 for the toe length and 0.9203 for the linear stiffness. Lastly, this study mimics the mechanical behavior of the human medial collateral ligament (MCL) by integrating the artificial ligament into a bio-fidelity knee model with a joint stiffness of 1.77 Nm/deg, resulting in a high degree of similarity with human knee in valgus-varus, further affirming the utility and applicability of this study. [ABSTRACT FROM AUTHOR]

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.

The purpose of the present study is to modify the polyethylene terephthalate ligament with hydroxyapatite via biomineralization and to investigate its effect on graft-bone healing. After biomineralization of hydroxyapatite, the surface characterization of polyethylene terephthalate ligament was examined by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and water contact angle measurements. The compatibility and osteoinduction, along with the underlying signaling pathway involved of hydroxyapatite-polyethylene terephthalate ligament, were evaluated in vitro. Moreover, a rabbit anterior cruciate ligament reconstruction model was established, and the polyethylene terephthalate or hydroxyapatite-polyethylene terephthalate artificial ligament was implanted into the knee. The micro-computed tomography analysis, histological, and immunohistochemical examination as well as biomechanical test were performed to investigate the effect of hydroxyapatite coating in vivo. The results of scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction showed that the hydroxyapatite was successfully deposited on the polyethylene terephthalate ligament. Water contact angle of the hydroxyapatite-polyethylene terephthalate group was significantly smaller than that of the polyethylene terephthalate group. The in vitro study showed that hydroxyapatite coating significantly improved adhesion and proliferation of MC3T3-E1 cells. The osteogenic differentiation of cells was also enhanced through the activation of ERK1/2 pathway. The micro-computed tomography, histological, and immunohistochemical results showed that biomineralization of hydroxyapatite significantly promoted new bone and fibrocartilage tissue formation at 12 weeks postoperatively. Moreover, the failure load and stiffness in the hydroxyapatite-polyethylene terephthalate group were higher than that in the polyethylene terephthalate group. Therefore, biomineralizaion of hydroxyapatite enhances the biocompatibility and osseointegration of the polyethylene terephthalate artificial ligament, thus promoting graft-bone healing for anterior cruciate ligament reconstruction through the activation of ERK1/2 pathway. [ABSTRACT FROM AUTHOR]

The goal of the present work is to investigate the effects of varying coatings on in vitro mineralization of silk fibroin fiber artificial ligaments (SFALs). Silk fibroin (SF) and sodium alginate (SA) aqueous solutions with varying concentrations were respectively employed for coating surfaces of the SFALs to improve calcium phosphate (CaP) deposition. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Energy-dispersive X-ray spectroscopy were utilized for characterizations. Furthermore, the surface of the SFAL was modified with SF/SA composite coatings. The volume ratios of the SF to the SA were set at 2:8, 4:6, 5:5, 6:4 and 8:2. The results show that either the SF or the SA coatings can improve the mineralization of the SFALs in vitro. The concentration of 1% for the SF and the SA coatings is conducive to deposit more calcium ions and obtain a biomimetic Ca/P ratio. Furthermore, the SF/SA composite coatings facilitate a thicker and uniform deposition layer than the SF and the SA coatings. The sediments are spherical particles and are more uniform in size. Therefore, the SF/SA composite coatings have more significant efficacy, particularly when the volume ratio of the SF to the SA was 4:6. The present work indicates that the SF/SA coatings possess excellent potential in promoting the osseointegration of artificial ligaments implanted in bone tunnels. [ABSTRACT FROM AUTHOR]

Pigmented villonodular synovitis (PVNS) is a proliferative disease that develops in the synovium of joints, especially the knee joints. A 52-year-old man visited our hospital with left knee pain, swelling and symptoms of collapse. Twenty-one years earlier, he had undergone anterior cruciate ligament (ACL) reconstruction using an active bioprosthetic composite (ABC) as an artificial ligament. T1 and T2 weighted magnetic resonance imaging of the knee joint showed rupture of the ABC ligament and low signal intensity of hyperplastic synovium. Arthroscopic total synovectomy without ACL reconstruction was performed and the lesion was histopathologically diagnosed as diffuse PVNS. Clinical outcomes included good pain relief and no recurrence of the disease after 5 years of follow-up. [ABSTRACT FROM AUTHOR]

Purpose: Various grafts were selected for restoring knee stability and regaining pre-injury activity levels after anterior cruciate ligament (ACL) rupture. This review aimed to compare the short-term knee outcomes of different tendon grafts for primary ACL reconstruction (ACLR).Methods: Databases of PubMed, Embase, and CENTRAL were retrieved for identifying the published RCT comparing the short-term (≤ 2 years) knee outcomes of different tendon grafts for ACLR. The main outcomes include the International Knee Documentation Committee (IKDC) subjective and objective scores, side-to-side difference on knee laxity, Lachman test, pivot-shift test, Lysholm score, Tegner score, all recorded complications and graft re-ruptures.Results: A total of 32 trials involving 2962 patients and 17 grafts were included. Superior IKDC subjective score was found for quadriceps tendon autograft (QTB) when compared with autografts including bone-patellar tendon-bone (BPTB), four-strand hamstring tendon (4S-HT), and double-bundle HT. The 4S-HT autograft was associated with poorer anteroposterior and rotational knee stability than the BPTB autograft. Artificial ligament also was found to provide lower knee stability compared with the autografts including the BPTB, patellar tendon, 4S-HT, 4S-HT with preserved tibial insertion, 6S-HT, and four-strand semitendinosus tendon. Additionally, the BPTB allograft showed a statistically higher knee laxity than 6S-HT allograft, while no difference was found between the genuine autografts and non-irradiated allografts.Conclusions: QTB was recommended to be used even over the BPTB and 4S-HT autografts. BPTB autograft was more effective on restoring the knee stability than 4S-HT autograft. Non-irradiated allografts could be safely used as alternatives to autografts. However, artificial ligaments were not recommended for primary ACLR for significantly increased risk of knee laxity. [ABSTRACT FROM AUTHOR]

Background: Different surgical fixation methods are available for the treatment of acromioclavicular (AC) joint dislocations. The aim of this study was to present the results of five years of experience with the Ligament Augmentation and Reconstruction System (LARS) fixation technique by a single surgeon. Methods: A single-center retrospective cohort study was performed. All patients treated for an AC joint dislocation with LARS fixation by the same surgeon between 2012 and 2016 (n=20) were eligible for inclusion. All these dislocations were unstable injuries, Rockwood type-III or higher, requiring acute or chronic repair. The primary outcome was the QuickDASH score. Secondary outcomes were the Subjective Shoulder Value (SSV), Numerical Rating Scale (NRS) pain score, return to work, complications, and implant removal. Results: 17 patients (85%) were available for final follow-up. The median follow-up was 23 months (IQR; 17-34). The median QuickDASH score was 7 (IQR; 2-18), the median SSV was 90 (IQR; 80-90), and the median NRS pain score was 2 (IQR; 1-3). Patients returned to work after a median of 8 weeks (IQR; 6-12). There was no significant difference in functional outcome scores between acute and chronic repair, or between the conventional and modified LARS fixation groups. There were two major complications requiring revision surgery, one ruptured LARS ligament and one case of deep wound infection. Implant removal was performed in one patient. Conclusions: The LARS ligament fixation technique seems to be effective for the treatment of AC joint dislocations, resulting in good short- and mid-term patient-reported functional outcome. LARS fixation might also be an acceptable treatment option for active patients with symptomatic chronic AC dislocations. Level of evidence: Level III, Retrospective Comparative Study, Treatment Study. [ABSTRACT FROM AUTHOR]

Abstract Background Critically evaluation and summarization for the outcomes between autografts and artificial grafts using in anterior cruciate ligament (ACL) reconstruction have not been performed currently. The purpose of this study is to compare the clinical outcomes between artificial ligaments and autografts at a short- to mid-term follow-up. Methods A computerized search of the databases was conducted including Medline, Embase, and the Cochrane library. Only prospective or retrospective comparative studies with a minimum 2-year follow-up and a minimum sample size of 15 for each group were considered for inclusion. Two independent reviewers performed data extraction and methodological quality assessment. A Mantel-Haenszel analysis was used for pooling of results. Sensitivity analysis was performed in order to maintain the stability of results. Results Seven studies were included in this study. The total sample size was 403 (autograft group: 206 patients; synthetic graft group: 197 patients). Four studies were randomized controlled trials. Two studies were retrospective comparative studies and one study was non-randomized prospective comparative study. In terms of instrumented laxity, patient-oriented outcomes and complications, no significant difference was occurred between new artificial ligaments and autografts. But the results of IKDC grades and instrumented laxity were worsen in early artificial ligaments compared to autografts. Conclusions The outcomes of new generation of artificial ligaments are similar to autografts at a short- to mid-term follow-up. However, the early artificial ligaments are not suggested for ACL reconstruction compared to autografts.

BACKGROUND: Artificial ligament material polyethylene terephthalate fiber has good physical-chemicalmechanical properties, but its surface affinity is poor, and it does not have good cell compatibility. Therefore, it is necessary to modify the surface of the material. OBJECTIVE: This study was designed to form active sites on the surface of polyethylene terephthalate fiber by ozone oxidation, and to improve its cell compatibility. METHODS: The polyethylene terephthalate fiber was braided into a grey fabric by warp knitting and cut into small cuts at suitable sizes. The small cuts were placed in distilled water for 30-minute ozone oxidation at room temperature with oxygen flow rate of 1 L/min and ozone concentration in aqueous solution of 10 mg/L. The surface morphology, mechanical properties, and toluidine blue adsorption of polyethylene terephthalate fiber were observed before and after ozone oxidation. RESULTS AND CONCLUSION: Scanning electron microscopy showed that the surface roughness of polyethylene terephthalate fiber increased slightly after ozone oxidation, and there was no obvious evidence of cracking degradation. After ozone oxidation, peroxy groups were successfully introduced onto the surface of polyethylene terephthalate fiber with a concentration of 10-5 mol/g. After ozone oxidation, the surface of the polyethylene terephthalate fiber did not show obvious degradation, and the mechanical property remained good. It can meet the requirement of the tensile properties of the artificial ligament material. Before ozone oxidation, the polyethylene terephthalate fiber lacked hydrophilic groups in the main chain, and hardly adsorbed toluidine blue. After ozone oxidation, toluidine blue absorption increased with the increase of hydrophilic groups on the surface of the fiber. All results suggest that ozone oxidation treatment not only ensures the mechanical property of polyethylene terephthalate fiber, but also introduces a sufficient amount of peroxy groups on its surface. [ABSTRACT FROM AUTHOR]

Anterior cruciate ligament (ACL) reconstruction is the leading treatment for ACL rupture. Ligament Advanced Reinforcement System (LARS), which is made of polyethylene terephthalate (PET), is the most frequently used artificial ligament for ACL reconstruction. However, PET is hydrophobic, so it is difficult to induce the ingrowth of the autologous tissue. The aim of this study is to explore the effects of silk hybrid on the ligamentization of the PET artificial ligament in a canine ACL reconstruction model. Silk/PET hybrid suspensory ligament was fabricated with silk in the weft yarn and PET in the warp yarn, while PET suspensory ligament was fabricated with PET in both the weft and warp yarns. After fabrication, the micromorphology of the ligaments was observed and mechanical testing was performed. Though the failure loads of the degummed silk/PET hybrid suspensory ligaments were significantly lower than those of the PET suspensory ligaments (P < 0.001), both of them were enough for ACL reconstructions of beagle dogs. In the animal study, 14 beagle dogs were divided into PET suspensory ligament group and silk/PET hybrid suspensory ligament group randomly, with 7 dogs in each. The dogs underwent ACL reconstructions in their right knees. At postoperative 6 months, the dogs were sacrificed, and the specimens were evaluated with gross observation, histology, immunohistochemistry, and mechanical testing. The histological and immunohistochemical results showed that the native ACL of the beagle dog held abundant fibroblasts and collagen. The PET‐regenerated ligament was loose, and there was a small amount of autologous tissue and collagen. Compared to the PET‐regenerated ligament, the silk/PET hybrid‐regenerated ligament had a compact structure, and there was more regenerated autologous tissue and collagen. In conclusion, compared to the PET ligament, the silk/PET hybrid ligament kept greater ability to induce the ingrowth of the autologous tissue, indicating that the silk hybrid had enhanced the ligamentization of the PET artificial ligament. [ABSTRACT FROM AUTHOR]

Anterior cruciate ligament reconstruction using polyethylene terephthalate artificial ligaments is one of the research hotspots in sports medicine but it is still challenging to achieve biological healing. The purpose of this study was to modify polyethylene terephthalate ligament with silk fibroin through ethyl-3–(3-dimethylaminopropyl)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) crosslink and to investigate the performance of graft remodeling in vitro and in vivo. After silk fibroin coating, changes in the surface properties of ligament were characterized by scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy and water contact angle measurements. The compatibility of polyethylene terephthalate ligament with silk fibroin coating was investigated in vitro. The results showed the silk fibroin coating significantly improved adhesion, proliferation and extracellular matrix secretion of fibroblast cells. Moreover, a rabbit anterior cruciate ligament reconstruction model was established to evaluate the effect of ligament with silk fibroin coating in vivo. The gross observation and histological results showed that the silk fibroin coating significantly inhibited inflammation response and promoted new tissue regeneration with fusiform cells infiltration in and around the graft. Furthermore, the expressions of collagen I protein and mRNA in the silk fibroin-coated polyethylene terephthalate group were much higher than those in the control group according to the immunohistochemical and real-time polymerase chain reaction results. Therefore, silk fibroin coating through EDC/NHS crosslink promotes the biocompatibility and remodeling process of polyethylene terephthalate artificial ligament in vitro and in vivo. It can be considered as a potential solution to the problem of poor remodeling of artificial ligaments after anterior cruciate ligament reconstruction in the clinical applications. [ABSTRACT FROM AUTHOR]

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Background: The purpose of this study was to evaluate mid- and long-term clinical and radiologic outcomes of arthroscopic coracoclavicular ligament reconstruction (ACCLR) with an artificial ligament for acute dislocation of the acromioclavicular joint (ACJ). Methods: Twelve male patients (average age at the time of surgery: 40.8 years, range: 21-64 years) underwent ACCLR with an artificial ligament for acute dislocation of the ACJ type III or type V according to the Rockwood classification. Arthroscopic surgery was performed with the patient under general anesthesia and interscalene brachial plexus block in the beach-chair position. Reduction of the ACJ was performed manually or using an elevator under control of an imaging intensifier. The ACJ was fixed temporarily with a Kirschner wire. Bone tunnels of the coracoid process and clavicle were made with a cannulated drill. An artificial ligament was pulled out through the bone tunnels and fixed on the upper surface of the clavicle with a staple and interference screw, and on the undersurface of the coracoid process with an Endobutton. The shoulder was immobilized with a shoulder brace for 4 weeks postoperatively, and rehabilitation was started in the first postoperative week. The Japan Shoulder Society Acromioclavicular Joint Function Assessment (JSS-ACJ) score was used for evaluation of clinical outcomes, and plain radiographs were performed after a minimum follow-up period of 5 years postoperatively. Results: The average follow-up period after surgery was 106.3 months (range: 62-128 months). The average postoperative JSS-ACJ score was 97.2 points (range: 92-100). The seven patients who had been playing sports before injury all returned to their pre-injury level. No patients complained of pain or shoulder dysfunction in daily activities, work, or sports. There were no complications such as neurovascular injuries during surgery, infection, or foreign body reaction from the artificial ligament. Radiographs at the final follow-up showed subluxation of the ACJ and non-symptomatic osteoarthritic changes of the ACJ in two patients, respectively. Conclusion: ACCLR for acute dislocation of the ACJ is a useful surgical procedure that gives satisfactory clinical and radiologic outcomes on mid- and long-term follow-up. ACCLR can stabilize vertical instability of the ACJ. If instability in the horizontal direction remains, repair or reconstruction of the acromioclavicular ligament should be added to prevent osteoarthritic changes of the ACJ. [ABSTRACT FROM AUTHOR]

Background: Hip dislocation is a major complication of total femoral prosthetic reconstruction (TFR) after femoral tumor resection. Hip dislocation can occur because of inadequate functional abductor musculature, inadequate hip capsule repair, or a long lever arm after total femur replacement. To eliminate the negative effects of these factors on the risk of hip dislocation, the use of artificial ligaments may help to increase the stability of the hip joint. We aimed to determine whether application of an artificial ligament would improve limb function and active range of movement (ROM) after TFR.Methods: Fifty-eight patients who underwent femoral tumor resection and TFR were included. A band-shaped artificial ligament was wrapped spirally around the proximal site of the total femur prosthesis for periacetabular soft tissue reconstruction in 12 patients. The other 46 patients did not consent to receiving the artificial ligament. Complications including hip dislocation and infection, limb function, and active hip ROM were compared between patients who did and did not receive the artificial ligament.Results: The hip dislocation rate was lower in the patients who received the artificial ligament. The risk of deep infection did not differ between groups. The group that received the ligament also achieved better limb function and active ROM on flexion and abduction.Conclusion: Patients treated with total femur resection and endoprosthetic replacement with an artificial ligament for periacetabular soft tissue reconstruction had a more stable hip joint, better limb function, and greater active hip ROM than did patients who did not receive an artificial ligament. [ABSTRACT FROM AUTHOR]

Autograft has been carried out for anterior cruciate ligament (ACL) reconstruction surgery. However, it has negative aspect because patients lose their healthy ligaments from other part. We focus on a chitosan-hydroxyapatite (HAp) composite fiber as a scaffold of ligament regeneration. Chitosan- HAp composite fiber was made by using coagulation method. Chitosan-NaH 2 PO 4 solution was coagulated with coagulation bath including calcium ion to get the mono-fiber and then treated with sodium hydroxide solution to form HAp in fiber matrix. The mechanical property of the fiber was improved by the stretching of the wet one because of the orientation of chitosan molecule and the interaction between chitosan and HAp. Maximum stress was improved with increasing of sodium dihydrogen phosphate until 0.03 M. The swelling ratio of the fiber was inhibited by composited with HAp. Additionally, bone-bonding ability was confirmed by SBF soaking tests. [ABSTRACT FROM AUTHOR]

To solve the poor healing of polyethylene terephthalate (PET) artificial ligament in bone tunnel, copper-containing bioactive glass (Cu-BG) nanocoatings on PET artificial ligaments were successfully prepared by pulsed laser deposition (PLD). It was hypothesized that Cu-BG coated PET (Cu-BG/PET) grafts could enhance the in vitro osteogenic and angiogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) and in vivo graft-bone healing after anterior cruciate ligament (ACL) reconstruction in a goat model. Scanning electron microscope and EDS mapping analysis revealed that the prepared nanocoatings had uniform element distribution (Cu, Ca, Si and P) and nanostructure. The surface hydrophilicity of PET grafts was significantly improved after depositing Cu-BG nanocoatings. The in vitro study displayed that the Cu-BG/PET grafts supported the attachment and proliferation of rBMSCs, and significantly promoted the expression of HIF-1α gene, which up-regulated the osteogenesis-related genes (S100A10, BMP2, OCN) and angiogenesis-related genes (VEGF) in comparison with PET or BG coated PET (BG/PET) grafts which do not contain Cu element. Meanwhile, Cu-BG/PET grafts promoted the bone regeneration at the graft-host bone interface and decreased graft-bone interface width, thus enhancing the bonding strength as well as angiogenesis (as indicated by CD31 expression) in the goat model as compared with BG/PET and pure PET grafts. The study demonstrates that the Cu-containing biomaterials significantly promote osteogenesis and angiogenesis in the repair of bone defects of large animals and thus offering a promising method for ACL reconstruction by using Cu-containing nanobioglass modified PET grafts. Statement of Significance It remains a significant challenge to develop an artificial graft with distinct osteogenetic/angiogenetic activity to enhance graft-bone healing for ligament reconstruction. To solve these problems, copper-containing bioactive glass (Cu-BG) nanocoatings on PET artificial ligaments were successfully prepared by pulsed laser deposition (PLD). It was found that the prepared Cu-BG/PET grafts significantly stimulated the proliferation and osteogenic/angiogenic differentiation of bone marrow stromal cells (BMSCs) through activating HIF-1α/S100A10/Ca 2+ signal pathway. The most important is that the in vivo bone-forming ability of Cu-containing biomaterials was, for the first time, elucidated in a large animal model, revealing the enhanced capacity of osteogenesis and angiogenesis with incorporation of bioactive Cu element. It is suggested that the copper-containing biomaterials significantly promote osteogenesis and angiogenesis in large animal defects and thus offering a promising method for ACL reconstruction by using Cu-containing nanobioglass modification of PET grafts, paving the way to apply Cu-containing biomaterials for tissue engineering and regenerative medicine. [ABSTRACT FROM AUTHOR]

A plasma- and precursor-assisted biomimetic process utilizing plasma and alternate dipping treatments was applied to a Leed-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.