Search

The article presents a clinical case on the use of a synthetic ligament for the resolution of chronic rupture of the Achilles tendon in a canine patient. It is an adult dog of large size with plantigrade support on the right hind leg. After performing a detailed physical examination and radiographs, the diagnosis of Achilles tendon rupture was reached. It was decided to perform a surgical treatment using a biocompatible synthetic ligament and an external fixation system to restore the functionality of the leg. [Extracted from the article]

It is aimed in this study study to determine the incidence of meniscus root tear in the knee and its effects on additional injuries related to the degree of meniscal extrusion, degree of chondrosis, malalingment and subchondral insufficiency fractures of the knee (SIFK). A total of 277 patients with a meniscal root tear detected on knee magnetic resonance imaging (MRI) taken between January 2011 and December 2020 were retrospectively analyzed. The severity of meniscal extrusion, osteophyte size and alignment were measured on MRI. Subchondral insufficiency fracture medial compartment osteoarthritis, lateral compartment osteoarthritis, additional ligament and meniscal injuries were recorded. The mean medial meniscal extrusion was 4.91 ± 2.2 mm and the mean lateral meniscal extrusion was 3.07 ± 1.56. While the mechanical alignment was 4.05 ± 2.24 degree varus in the patients with medial meniscus root tear, 1.88 ± 3.55 degree valgus in those with lateral meniscus injury. The mean size of tibial osteophyte was 2.51 ± 1.06 mm. In arthrosis grading conducted by using the International Cartilage Repair Society (ICRS) MRI-based grading system, the meniscal extrusion was measured to be 3.09 ± 1.1 mm in grade I, 5.04 ± 2.25 mm in grade II, 5.8 ± 2.01 in grade III and 6.05 ± 1.2 mm in grade 4. A statistically significant relationship was found between meniscal extrusion and age and mechanical alignment (p < 0.001). It was determined that, the patients having high-grade meniscal extrusion suffered from high-grade chondrosis, varus and SIF lesions. It was concluded that meniscus posterior root tear (MPRT) induces meniscal extrusion (MME) leading to subchondral insufficiency fracture of the knee, varus, and gonarthrosis. [ABSTRACT FROM AUTHOR]

Chronic lateral ankle instability (CLAI) is a condition that is characterized by persistent disability and recurrent ankle sprains while encompassing both functional and mechanical (laxity) instability. Failure of conservative treatment for CLAI often necessitates operative intervention to restore the stability of the ankle joint. The traditional or modified Broström techniques have been the gold standard operative approaches to address CLAI with satisfactory results; however, patients with generalized ligament laxity (GLL), prior unsuccessful repair, high body mass index, or high-demand athletes may experience suboptimal outcomes. Synthetic ligament constructs have been tested as an adjunct to orthopedic procedures to reinforce repaired or reconstructed ligaments or tendons with the hope of early mobilization, faster rehabilitation, and long-term prevention of instability. Suture tape augmentation is useful to address CLAI. Multiple operative techniques have been described. Because of the heterogeneity among the reported techniques and variability in postoperative rehabilitation protocols, it is difficult to evaluate whether the use of suture tape augmentation provides true clinical benefit in patients with CLAI. This review aims to provide a comprehensive outline of all the current techniques using suture tape augmentation for treatment of CLAI as well as present recent research aimed at guiding evidence-based protocols. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) fibers and fabrics are widely used for medical device applications such as vascular and anterior cruciate ligament prostheses. Several years ago, we began functionalizing PET fabrics using anionic polymers to enhance their biocompatibility, cell adhesion, proliferation and functional performance as PET ligament prostheses. Polymer functionalization followed a grafting-from process from virgin PET surfaces subject to spin-finish oil additive removal under Soxhlet extraction to remove residual fiber manufacturing oil. Nevertheless, with increasing time from manufacture, PET fabrics stored without a spin finish removal step exhibited degradation of spin finish oil, leading to (1) incomplete surface cleaning, and (2) PET surface degradation. Moreover, oxidizing agents present in the residual degraded oil prevented reliable functionalization of the prosthesis fibers in these PET fabrics. This study compares effects of PET fabric/spin finish oil storage on PET fabric anionic polymer functionalization across two PET fabric ligament storage groups: (1) 2- and 10- year old ligaments, and (2) 26-year old ligaments. Strong interactions between degraded spin finish oil and PET fiber surfaces after long storage times were demonstrated via extraction yield; oil chemistry changed assessed by spectral analysis. Polymer grafting/functionalization efficiency on stored PET fabrics was correlated using atomic force microscopy, including fiber surface roughness and relationships between grafting degree and surface Young's modulus. New PET fabric Young's modulus significantly decreased by anionic polymer functionalization (to 96%, grafting degree 1.6 µmol/g) and to reduced modulus and efficiency (29%) for 10 years storage fabric (grafting degree ~ 1 µmol/g). As fiber spin finish is mandatory in biomedically applicable fiber fabrication, assessing effects of spin finish oil on commercial polymer fabrics after longer storage under various conditions (UV light, temperature) is necessary to understand possible impacts on fiber degradation and surface functionalization. [ABSTRACT FROM AUTHOR]

Abstract Background The anterior cruciate ligament rupture is a common injury which mainly affects young and active population. Faced to this problem, the development of synthetic structures for ligament reconstruction is increasing. The most recent researches focused on the development of biodegradable structures that could be functionalized to enhance host integration. This work describes the elaboration of different poly(ε -caprolactone) prototypes for the rat anterior cruciate ligament replacement in order to found the best design for further in vivo assays. Methods According to the literature, it was decided to elaborate two different poly(ε -caprolactone) prototypes: a braided one and a free-fibers one. A chemical grafting of a bioactive polymer–poly(sodium styrene sulfonate) – was performed on both prototypes and mechanical and biological testing were assessed. Based on these results, one rat was implanted with the best prototype. Results The mechanical and biological results demonstrated that the best prototype to implant was the poly(sodium styrene sulfonate)-grafted braided prototype. After one-month implantation, no inflammation was observable around the scar. The rat demonstrated good flexion and extension of the lower limb without any anterior drawer. The prototype was highly anchored to the bone. ESEM images of the explanted prototype showed the presence of cells and tissue ingrowth along and around the fibers. Conclusion This work demonstrates the feasibility to implant a bioactive and biodegradable synthetic ligament in the rat model without any inflammation and with a good tissue anchoring at a short-term time. This will lead to an extensive in vivo assay. Graphical abstract Highlights • The set up pNaSS grafting process can be extended to a fibers complex structure. • The pNaSS grafting improves cell proliferation and spreading. • pNaSS-grafted PCL synthetic ligament can be successfully implanted in rat model. [ABSTRACT FROM AUTHOR]

Background: Demand for short recovery and less invasive correction for moderate skin and soft tissue neck laxity is increasing, especially among younger patients. The current study aims to evaluate the feasibility of a short recovery and minimally invasive technique of polytetrafluoroethylene (PTFE) bands and minimal skin excision for moderate platysma and skin laxity.Methods: Following periauricular incision, PTFE bands of dual mesh are customized for suture to the platysma and anchored to the mastoid, creating a neck artificial ligament (NAL). NAL is buried into the muscle and tightened, without modifying the superficial musculoaponeurotic system and platysma. Young patients with moderate platysma and skin laxity were enrolled. Outcome was measured in terms of complications, recovery time, and patient and clinician satisfaction (1 = very dissatisfied, 2 = dissatisfied, 3 = satisfied, and 4 = very satisfied).Results: A population of 107 consecutive patients (94% female) was treated, January 2013-January 2017. Average patient age was 51 years (46-56). Complications were rare: 1 case of superficial epidermolysis (healed within 21 days) and 1 case of mild band infection (treated with antibiotics). At a mean follow-up of 16 months, average patient and clinician evaluations were satisfactory (average satisfaction: patient 3.2, clinician 3.1).Conclusions: In young patients with moderate platysma and skin laxity, minimally invasive NAL avoids deep modifications of the superficial musculoaponeurotic system and platysma. Despite the relative short follow-up of this study, the low rate of complications, short recovery time, and acceptable patient and clinician satisfaction seem promising.Level of Evidence: Level IV, therapeutic study. [ABSTRACT FROM AUTHOR]

Force distribution with natural teeth depends on micromovement induced by the periodontal ligament. The location and cusp inclination of the tooth qualitatively alter the force pattern. Osseointegrated implants do not have micromovement associated with force distribution. Force distribution to the osseointegrated implant interface is completely different than with natural teeth. Alterations in tooth location and cusp inclination are suggested to limit implant overload. Force distribution in splinted natural teeth and osseointegrated prostheses are compared. The mechanism of interface force distribution and the consequences of poor interface fit are interrelated. The differential mobility of splinted natural teeth affects diagnosis and treatment. However, combining natural teeth with an osseointegrated prosthesis requires new design principles. [ABSTRACT FROM AUTHOR]

Chronic rupture of the patellar tendon is a severe injury that leads to dramatic functional consequences including lack of extension and walking difficulty. Surgery is the gold standard to treat this type of injury, but revision reconstructions are problematic because an ipsilateral graft was often harvested for the initial surgery. Because fibrotic tissues on the patellar tendon need to be debrided, another graft must be added to reinforce the tendon. We reported the case of a former semiprofessional handball player, a 29-year-old man who presented an iterative rupture with the fracture of the transverse patellar tunnel 6 months after reconstruction using a semitendinosus graft and suture repair. We performed revision reconstruction surgery using an artificial ligament placed between the extensor mechanism and the tibia for extra-articular reinforcement to maintain extensor mechanism continuity. Two adjustable loops were also used to repair the patellar tendon tear. At 2-year follow-up, the patient was able to resume the practice of handball at a competitive level with good clinical and functional results. This technique can therefore be used as a salvage procedure for chronic iterative rupture of the patellar tendon. [ABSTRACT FROM AUTHOR]

Abstract: Ligament reconstruction using a tissue‐engineered artificial ligament (TEAL) requires regeneration of the ligament‐bone junction such that fixation devices such as screws and end buttons do not have to be used. The objective of this study was to develop a TEAL consisting of elastin‐coated polydioxanone (PDS) sutures covered with elastin and collagen fibers preseeded with ligament cells. In a pilot study, a ring‐type PDS suture with a 2.5 mm (width) bone insertion was constructed with/without elastin coating (Ela‐coat and Non‐coat) and implanted into two bone tunnels, diameter 2.4 mm, in the rabbit tibia (6 cases each) to access the effect of elastin on the bond strength. PDS specimens taken together with the tibia at 6 weeks after implantation indicated growth of bone‐like hard tissues around bone tunnels accompanied with narrowing of the tunnels in the Ela‐coat group and not in the Non‐coat group. The drawout load of the Ela‐coat group was significantly higher (28.0 ± 15.1 N, n = 4) than that of the Non‐coat group (7.6 ± 4.6 N, n = 5). These data can improve the mechanical bulk property of TEAL through extracellular matrix formation. To achieve this TEAL model, 4.5 × 106 ligament cells were seeded on elastin and collagen fibers (2.5 cm × 2.5 cm × 80 µm) prior to coil formation around the elastin‐coated PDS core sutures having ball‐shape ends with a diameter of 2.5 mm. Cell‐seeded and cell‐free TEALs were implanted across the femur and the tibia through bone tunnels with a diameter of 2.4 mm (6 cases each). There was no incidence of TEAL being pulled in 6 weeks. Regardless of the remarkable degradation of PDS observed in the cell‐seeded group, both the elastic modulus and breaking load of the cell‐seeded group (n = 3) were comparable to those of the sham‐operation group (n = 8) (elastic modulus: 15.4 ± 1.3 MPa and 18.5 ± 5.7 MPa; breaking load: 73.0 ± 23.4 N and 104.8 ± 21.8 N, respectively) and higher than those of the cell‐free group (n = 5) (elastic modulus: 5.7 ± 3.6 MPa; breaking load: 48.1 ± 11.3 N) accompanied with narrowed bone tunnels and cartilage matrix formation. These data suggest that elastin increased the bond strength of TEAL and bone. Furthermore, our newly developed TEAL from elastin, collagen, and ligament cells maintained the strength of the TEAL even if PDS was degraded. [ABSTRACT FROM AUTHOR]

Copyright of Summa, Animali da Compagnia is the property of Point Veterinaire Italie s.r.l. 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.)

Objective: To compare the biomechanical and histological changes in a rabbit model after reconstructing the anterior cruciate ligament (ACL) with solely autologous tendon and with autologous tendon combined with the ligament advanced reinforcement system (LARS) artificial ligament. Methods: Anterior cruciate ligament reconstruction was performed in 72 knees from 36 healthy New Zealand white rabbits (bodyweight, 2500–3000 g). The Achilles tendons were harvested bilaterally. The left ACL were reconstructed solely with autografts (autologous tendon group), while the right ACL were reconstructed with autografts combined with LARS ligaments (combined ligaments group). The gross observation, histological determination, and the tension failure loads in both groups were evaluated at 12 weeks (n = 18) and 24 weeks (n = 18) postoperatively. Results: Gross examination of the knee joints showed that all combined ligaments were obviously covered by a connective tissue layer at 12 weeks, and were completely covered at 24 weeks. Fibrous tissue ingrowth was observed between fascicles and individual fibers in the bone–artificial ligament interface at both time points; this fibrovascular tissue layer localized at the bone–artificial ligament interface tended to be denser in specimens obtained at 24 weeks compared with those obtained at 12 weeks. The tension failure loads of the knees were similar in the autologous tendon group and the combined ligaments group at 12 weeks (144.15 ± 3.92 N vs. 140.88 ± 2.75 N; P > 0.05), and at 24 weeks (184.15 ± 1.96 N vs. 180.88 ± 3.21 N; P > 0.05). Conclusion: Reconstructing the ACL in rabbits using autologous tendon combined with the LARS artificial ligament results in satisfactory biointegration, with no obvious immunological rejection between the autologous tendon and the artificial ligament, and is, therefore, a promising ACL reconstruction method. [ABSTRACT FROM AUTHOR]

The purpose of this study was to describe and assess the feasibility of a new intra-articular approach in the treatment of cranial cruciate ligament deficiency in dogs using an artificial ligament and a new bone-anchor system. Twelve canine cadavers weighting 26 to 45 kg were used in this ex-vivo study. Special tibial and femoral screws, two helicoils and a high resistance artificial fiber compose the implant. Surgery was performed using the cranio-lateral approach to the stifle joint. Helicoil and tibial screw, connected to the fiber, were inserted in the center of the tibial insertion area of the cranial cruciate ligament. The fiber was passed over-thetop, tensioned and fixed to the femoral screw, previously inserted with the helicoil in the distal part of the femur. Surgery was completed in all the cases. Occasional problems found during the insertion of the helicoils and screws were resolved with simple procedures. Post-operative clinical assessment showed negative cranial drawer test, negative cranial tibial thrust and normal range of motion. Radiographic evaluation showed an appropriate positioning of both tibial and femoral implants in all the cases. The results of the first surgical appraisal of this new technique are encouraging, although further studies are necessary to demonstrate the in vivo efficacy of this procedure. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate whether the local use of estradiol after anterior cruciate ligament (ACL) reconstruction with a polyethylene terephthalate (PET) artificial ligament graft could promote graft-bone healing. A total of 45 New Zealand white rabbits underwent ACL reconstruction with a PET ligament graft. The experimental groups were administered a local estradiol injection at either a low dose after surgery or a high dose after surgery, and the control group did not receive an injection. Computed tomography (CT) scans and blood sample collection were routinely performed in all three groups. Over time, the serum estradiol levels increased in both experimental groups, and the CT images revealed a trend of a shrinking bone tunnel area in all three groups. The rabbits were randomly sacrificed at 2, 4, and 8 weeks after surgery. The load to failure and stiffness of the experimental groups were significantly higher than those of the control group at 4 and 8 weeks. The histological study identified more bone mineralization in the experimental groups at 4 weeks after surgery compared to the control group. This study showed that the use of estradiol is a promising approach in promoting graft-bone healing in rabbits undergoing ACL reconstruction with a PET ligament graft. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Giant cell tumor of the bones occurring in the first metacarpals frequently requires entire metacarpal resection due to the aggressive nature and high rate of recurrence. Bone reconstruction can be performed with autogenous bone grafts. Here we describe a new technique of reconstruction using a patient-matched three-dimensional printed titanium first metacarpal prosthesis. This prosthesis has a special design for ligament reconstruction in the proximal and distal portions. Good hand function and aesthetic appearance were maintained at a 24-month follow-up visit. This reconstructive technique can avoid donor-site complications and spare the autogenous bone grafts for revision options. [ABSTRACT FROM AUTHOR]

Various surgical techniques have been described for the fixation of acromioclavicular (AC) dislocations. However, recurrent dislocation is one of the main complications associated with the majority of these techniques. We report a case of postoperative AC joint redislocation. In order to overcome recurrent dislocation after revision surgery, a reconstruction of the conoid and trapezoid ligament with the use of a free tendon graft in combination with a FiberTape was provided within a novel surgical technique. After 12 months, the patient was very satisfied with the functional outcome. The patient achieved excellent results in the Constant (98 points), SPADI (0 points), and QuickDASH score (0 points). The described technique results in an anatomic reconstruction of the AC joint. The nonrigid nature of the intervention seems to restore the normal arthrokinematics by reconstructing the coracoclavicular ligaments with an autograft which is then protected by the AC Dog Bone artificial ligaments during the healing period. The arthroscopic approach to the AC joint with minimal exposure reduces the risks and complications of the intervention. This is the first case in literature that utilizes the artificial dog bone ligament securing the autograft in an anatomic AC reconstruction. [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]

The objective of this study is to study the bioactivity and osseointegration of polyethylene-terephthalate-based artificial ligament coated with mesoporous bioactive glass (MBG) via polydopamine (PDA) in vitro and in vivo. In vitro, the OD value of MC3T3-E1 cells on PDA-MBG modified grafts is around 108% higher than that on pure PET after 5 days of culturing. The ALP activity of the PDA-MBG group is about 1.5 times higher than that of the control group after 7 days of culturing. In the in vivo study, the results demonstrated that more newly formed bone tissue was found and the ultimate failure load increased in the PDA-MBG coating group. In conclusion, PDA and MBG coating improves the surface bioactivity of the polyethylene-terephthalate-based artificial ligament and enhances the osseointegration within a bone tunnel. [ABSTRACT FROM AUTHOR]

Purpose: Condylar lift-off can induce excessive polyethylene wear after total knee arthroplasty (TKA). A computer simulation was used to evaluate the influence of femoral varus alignment and lateral collateral ligament (LCL) laxity on lift-off after single-design TKA. It was hypothesised that proper ligament balancing and coronal alignment would prevent lift-off.Methods: The computer model in this study is a dynamic musculoskeletal program that simulates gait up to 60° of knee flexion. The lift-off phenomenon was defined as positive with an intercomponent distance of >2 mm. In neutrally aligned components in the coronal plane, the femoral and tibial components were set perpendicular to the femoral and tibial mechanical axis, respectively. The femoral coronal alignment was changed from neutral to 5° varus in 1° increments. Simultaneously, the LCL length was elongated from 0 to 5 mm in 1-mm increments to provide a model of pathological slack.Results: Within 2° of femoral varus alignment, lift-off did not occur even if the LCL was elongated by up to 5 mm. However, lift-off occurred easily in the stance phase in femoral varus alignments of >3° with slight LCL slack. The contact forces of the tibiofemoral joint were influenced more by femoral varus alignment than by LCL laxity.Conclusions: Aiming for neutral alignment in severely varus knees makes it difficult to achieve appropriate ligament balance. Our study suggests that no lift-off occurs with excessive LCL laxity alone in a neutrally aligned TKA and therefore that varus alignment should be avoided to decrease lift-off after TKA.Level Of Evidence: Case series, Level IV. [ABSTRACT FROM AUTHOR]

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]

Background: Longitudinal changes in patellar stiffness following reconstruction of the medial patellofemoral ligament for recurrent patellar dislocation at full extension are unknown.Methods: Fifteen consecutive patients (three men and twelve women, with a mean age of twenty-two years) with seventeen knees were matched by sex and age to thirty-two reference subjects in this prospective study. The follow-up period was a minimum of twenty-four months. The medial patellofemoral ligament reconstruction used an autograft semitendinosus tendon and an interference screw system with or without lateral release under 10 N of laterally directed force. The medial patellar stiffness and lateral patellar stiffness were measured in 0° of knee extension using the Patella Stability Tester preoperatively; postoperatively at three, six, twelve, and eighteen months; and at the time of the latest follow-up. Before and after the surgical procedure, patients were evaluated for apprehension and Kujala and Lysholm scores; radiographic examinations were performed to evaluate changes, including osteoarthritic changes.Results: The medial stiffness of the affected side before the surgical procedure was significantly lower than the lateral stiffness (p = 0.004) and the stiffness for healthy reference knees (p = 0.004). Medial stiffness three months after the surgical procedure was significantly elevated compared with lateral values (p = 0.027), preoperative values (p < 0.001), and reference group values (p = 0.002); reached the reference level by six months; and was maintained for up to two years. Furthermore, medial stiffness and lateral stiffness were well balanced after six months and this balance was sustained for up to two years postoperatively. No recurrent dislocation occurred during the follow-up period; one patient experienced apprehension. Postoperative radiographic findings and clinical scores were significantly improved at the time of the latest follow-up (p < 0.05). One knee progressed to patellofemoral osteoarthritis.Conclusions: The value for medial stiffness was significantly improved three months after medial patellofemoral ligament reconstruction compared with the preoperative and lateral values and returned to the reference level by six months. Medial stiffness and lateral stiffness of the patella were well balanced by six months and retained that balance for up to two years, with good clinical results.Level Of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Artificial ligaments utilized in reconstruction of anterior cruciate ligament ( ACL) are usually made of polyethylene terepthalate ( PET) because of its good mechanical properties in vivo. However, it was found that the deficiencies in hydrophilicity and biocompatibility of PET hindered the process of ligamentization. Therefore, surface modification of the PET is deemed as a solution in resolving such problem. Silk fibroin ( SF), which is characterized by good biocompatibility and low immunogenicity in clinical applications, was utilized to prepare a coating on the PET ligament ( PET+ SF) in this work. At first, decrease of hydrophobicity and appearance of amino groups were found on the surface of artificial PET ligament after coating with SF. Second, mouse fibroblasts were cultured on the two different kinds of ligament in order to clarify the possible effect of SF coating. It was proved that mouse fibroblasts display better adhesion and proliferation on PET+ SF than PET ligament according to the results of several technical methods including SEM observation, cell adhesive force and spread area test, and mRNA analysis. Meanwhile, methylthiazolyldiphenyl-tetrazolium bromide and DNA content tests showed that biocompatibility of PET+ SF is better than PET ligament. In addition, collagen deposition tests also indicated that the quantity of collagen in PET+ SF is higher than PET ligament. Based on these results, it can be concluded that SF coating is suggested to be an effective approach to modify the surface of PET ligament and enhance the 'ligamentization' process in vivo accordingly. [ABSTRACT FROM AUTHOR]

In Total Knee Arthroplasty (TKA), the collateral ligament tensioning stage cannot be standardised for all patients and relies heavily on the surgeon’s experience and perception. Intraoperative inaccuracies are practically unavoidable and may give rise to severe postoperative complications, leading to the need for revision surgery already a few years after primary TKA. This work proposes a novel instrumented tibial component able to detect collateral ligament laxity conditions right after primary TKA and, if needed, to compensate for them in the postoperative period. A miniaturised actuation system, designed to be embedded in the tibial baseplate, was initially evaluated by means of 3D simulations and then fabricated as a full-scale prototype. Stability and force sensors tests carried out on a knee simulator allowed to assess the effectiveness of the proposed design under normal working conditions and provided valuable insights for future work and improvements. [ABSTRACT FROM AUTHOR]

This report deals with the preparation of a 'true' artificial phrenoesophageal ligament aimed at restoring effective anchoring of the esophagus to the diaphragm, keeping the esophagogastric sphincter in the abdomen. A total of 24 mongrel dogs were assigned to four groups: (i) Group I ( n = 4): the esophageal diaphragm hiatus left wide open; (ii) Group II ( n = 8): the anterolateral esophagus walls were attached to the diaphragm by the artificial ligament and the esophageal hiatus was left wide opened; (iii) Group III ( n = 5): in addition to the use of the artificial ligament, the esophageal hiatus was narrowed with two retroesophageal stitches; (iv) Group IV ( n = 7): the only procedure was the esophageal hiatus narrowing with two retroesophageal stitches. The phrenoesophagogastric connections were released, sparing the vagus nerves. Five animals of groups III and IV, which did not develop hiatal hernia, were submitted to esophageal manometry immediately before and 15 days after surgery. In group I, all animals developed huge sliding hiatal hernias. In group II, two dogs (25%) had a paraesophageal hernia between the two parts of the artificial ligament. In group III, neither sliding hiatal hernia nor paraesophageal hernia occurred. In group IV, two animals (28.6%) developed sliding esophageal hiatus hernia. Regarding esophageal manometry, postoperative significant difference between groups III and IV ( P = 0.008) was observed. Thus, the artificial phrenoesophageal ligament maintained the esophagus firmly attached to the diaphragm in all animals and the esophagogastric sphincter pressure was significantly higher in this group. [ABSTRACT FROM AUTHOR]

Purpose: This prospective case series is designed to determine the 2-year clinical and radiological outcomes of patients undergoing an ACL reconstruction using the ligament augmentation reconstruction system (LARS) 133 prosthesis as an augmentation device for a 4-tunnel autologous hamstrings graft, in the context of accelerated rehabilitation. Methods: A total of 91 patients were assessed at 2 years post-operatively after undergoing an anterior cruciate ligament reconstruction (ACLR) with a doubled semitendinosis and LARS 133 prosthesis for the anteromedial bundle (AMB) and gracilis for the posterolateral bundle. Assessment included clinical review, KT-1000 arthrometry, IKDC, Tegner, Lysholm, Cincinnati and ACL QOL knee scoring, graft failure and re-operation rates. Tunnel positions and synovitis were assessed using gadolinium magnetic resonance imaging (MRI) scans and X-rays. Results: This technique in the context of accelerated rehabilitation is not associated with increased knee laxity and failure. There was no increase in knee laxity, with a mean side-to-side difference in KT-1000 arthrometer testing of 0.5mm (/ 1.7). Two-year outcomes were satisfactory with 98% of all patients having an IKDC rating of A or B, and mean values of IKDC subjective 86.5 (/ 11.6), Tegner 6.5 (/ 2.0), Lysholm 87.1 (/ 8.9), Cincinnati 378.8 (/ 41.5) and ACL Quality of Life 81.5 (/ 19.3). There was no evidence of synovitis and all tunnels were positioned satisfactorily. The graft failure rate was 1.1% and there was a re-operation rate of 15.4%. Conclusion: We conclude that LARS 133 augmentation of autologous hamstrings ACLR provides a graft construct allowing accelerated rehabilitation without increased knee laxity. It is not associated with significant synovitis within the first two years. Re-operation rates however are higher. The rates at which patients recover and return to life and sports activity following different ACLR graft types appears as a topic of future research interest. [ABSTRACT FROM AUTHOR]

Case: We report the case of a twelve-year-old boy with limb deformity caused by physeal closure after transphyseal intraarticular reconstruction of the anterior cruciate ligament of the left knee at the age of seven years. We treated premature closure of the physis with a Langenskiöld procedure. Lengthening and correction of the deformity were accomplished with use of the Ilizarov method. Although gross instability remained, reasonable limb alignment was attained with prolonged treatment. Conclusion: We document growth arrest and severe limb deformity after transepiphyseal anterior cruciate ligament reconstruction with an artificial polyester ligament and successful surgical correction. [ABSTRACT FROM AUTHOR]

Anterior cruciate ligaments (ACL) have to meet a number of physiological and biomechanical requirements. Most of the permanent prostheses that have been developed suffer from fatigue, creep, and mechanical failure. This study aims to develop a new braided synthetic ligament which offers a high elasticity ensuring a long-term mechanical performance. Two braided structures were designed: a biaxial quadruple braid and a triaxial quadruple braid incorporating polyurethane filaments. The mechanical properties of these structures were measured and compared to those of the natural ligaments. The elastic recovery under a traumatic force was also studied in order to compare the elasticity of the manufactured samples. The obtained results showed that the elastic recuperation was improved, thanks to the incorporation of polyurethane yarns. These yarns provide prostheses with mechanical properties that closely match those of the native ACL. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate- (PET-) based artificial ligaments (PET-ALs) are commonly used in anterior cruciate ligament (ACL) reconstruction surgery. The effects of different porous structures on the migration of bone marrow mesenchymal stem cells (BMSCs) on artificial ligaments and the underlying mechanisms are unclear. In this study, a cell migration model was utilized to observe the migration of BMSCs on PET-ALs with different porous structures. A rabbit extra-articular graft-to-bone healing model was applied to investigate the in vivo effects of four types of PET-ALs, and a mechanical test and histological observation were performed at 4 weeks and 12 weeks. The BMSC migration area of the 5A group was significantly larger than that of the other three groups. The migration of BMSCs in the 5A group was abolished by blocking the RhoA/ROCK signaling pathway with Y27632. The in vivo study demonstrated that implantation of 5A significantly improved osseointegration. Our study explicitly demonstrates that the migration ability of BMSCs can be regulated by varying the porous structures of the artificial ligaments and suggests that this regulation is related to the RhoA/ROCK signaling pathway. Artificial ligaments prepared using a proper knitting method and line density may exhibit improved biocompatibility and clinical performance. [ABSTRACT FROM AUTHOR]

Purpose: This prospective randomized study compared acute and chronic anterior cruciate ligament (ACL) reconstruction using ligament advanced reinforcement system (LARS) artificial ligament in young active adults with a 5-year follow-up. Methods: Fifty-five patients were enrolled in this study and divided into two groups based on the elapsed time between the injury and reconstruction: the acute group (3-7 weeks) and the chronic group (6-11 months). The clinical outcomes were evaluated using the Lysholm knee scoring scale, the Tegner activity rating, a KT-1000 Arthrometer, and the International Knee Documentation Committee (IKDC) scoring system. Isokinetic strength of the quadriceps and hamstring was assessed using the Biodex System 3 isokinetic dynamometer. Results: Anterior laxity was decreased and quadriceps/hamstring muscle strength was increased in the acute group compared to the chronic group ( p > 0.05). There were no statistically significant differences in Lysholm scores, Tegner activity scores, and the IKDC evaluation form between the two groups. Conclusions: These results suggest that earlier ACL reconstruction using a LARS artificial ligament may provide an advantage in the treatment and rehabilitation of ACL rupture. [ABSTRACT FROM AUTHOR]

Introduction: The triangular fibrocartilage complex is in conjunction with the interosseous membrane the most important stabilizer of the distal radioulnar joint. Lesions of the triangular fibrocartilage complex may cause instability of the distal radioulnar joint with serious consequences. Therefore, the goal is to reconstruct and provide stability to prevent further harm. Surgical technique: Based on the anatomical configuration of the radioulnar ligaments, we present a technique which addresses both the deep and the superficial fibers of the radioulnar ligaments. This surgical procedure can be performed either openly or arthroscopically assisted. Two osseous 2-mm tunnels starting from the ulnar neck to the foveal surface are created. A nonabsorbable suture is passed through the tunnels and the triangular fibrocartilage using a 20-gauge venipuncture needle in order to attach the deep fibers. Then a third osseous tunnel starting from the lateral base of the styloid process to the medial aspect is created. The suture is passed through this tunnel and through the triangular fibrocartilage and around the styloid process palmarily using the same needle as before in order to anchor the superficial fibers anatomically. After reducing the ulna head the sutures are tightened. Conclusion: This technique is quite simple and addresses the anatomical configuration of the radioulnar ligaments. [ABSTRACT FROM AUTHOR]

Introduction: Surgical reconstruction has been increasingly recommended for the surgical management of posterior cruciate ligament (PCL) ruptures. While the choice of tissue graft still remains controversial. Currently both hamstring tendon autograft (HTG) and ligament advanced reinforcement system (LARS) artificial ligament are widely used but there are seldom reports on the comparisons of their clinical results. Our study was aimed to assess the effectiveness of these two grafts. Materials and methods: Thirty-five patients with unilateral PCL rupture were enrolled in this retrospectively study. Sixteen of them received arthroscopically assisted PCL reconstruction using hamstring tendon autografts (HTG group) and nineteen using LARS ligaments (LARS group). All cases were followed up for 46-57 months with a mean of 51 months. Follow-up examinations included radiographic assessment, Lysholm score, Tegner score, International Knee Documentation Committee (IKDC) rating scales and KT-1000 test. Results: All patients improved significantly at the final follow-up compared with the examinational results preoperatively and there were no significant differences between HTG group and LARS group with respect to the results of radiographic assessment, Lysholm score, Tegner score, IKDC rating scales and KT-1000 test. Conclusions: Similar good clinical results were obtained after PCL reconstruction using hamstring tendon autografts and LARS ligaments. Both LARS ligament and hamstring tendon autograft are ideal grafts for PCL reconstruction. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate mid-term follow-up results of medial patellofemoral ligament (MPFL) reconstruction using a bioactive synthetic ligament in the treatment of objective patellofemoral (PF) instability. Methods: Sixteen patients (18 knees) presenting with objective PF instability underwent a MPFL reconstruction, isolated or associated with other surgical procedures for PF stabilization. All patients were clinically evaluated at a minimum follow-up of 3 years. Kujala, subjective IKDC and KOOS scores were used to assess clinical outcome. Pre-operative and post-operative pain was quantified with VAS scale and the overall satisfaction graded according to Insall and Crosby. Although none of the patients in this series were involved in high-level sports activity because of patellofemoral instability, activity level pre-operatively and at follow-up were evaluated according to Tegner scale. Results: No recurrence of dislocation was observed in this series. The overall satisfaction rate was 88.8 %. Kujala score improved significantly from 57 ± 8.4 to 84.3 ± 10.2 points ( p < .01). Both subjective IKDC (42.4 ± 7.13 to 70.1 ± 3.9) and KOOS (62.7 ± 4.34 to 82.8 ± 8.8) significantly improved from pre-operative evaluation ( p < .01). VAS decreased from a mean pre-operative value of 2.5 ± 1.6 to 1.4 ± 1.5 at 3 years follow-up. Only one patient required revision debridement surgery for persistent medial epicondylar pain. Conclusions: Isolated or associated MPFL reconstruction with bioactive synthetic ligament is a valid option in surgical treatment of objective PF instability, with results at mid-term follow-up comparable to autologous graft, thus minimizing donor-site morbidity and associated complications. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

The extensor apparatus, an aponeurosis that covers the dorsal side of each finger, transmits force from a number of musculotendons to the phalanges. Multiple tendons integrate directly into the structure at different sites and the extensor apparatus attaches to the phalanges at multiple points. Thus, prediction of the force distribution within the extensor apparatus, or hood, and the transmission to the phalanges is challenging, especially as knowledge of the underlying mechanical properties of the tissue is limited. We undertook quantification of some of these properties through material testing of cadaver specimens. We punched samples at specified locations from 19 extensor hood specimens. Material testing was performed to failure for each sample with a custom material testing device. Testing revealed significant differences in ultimate load, ultimate strain, thickness, and tangent modulus along the length of the extensor hood. Specifically, thickness, ultimate load, and ultimate strain were greater in the more proximal sections of the extensor hood, while the tangent modulus was greater in the more distal sections. The variations in mechanical properties within the hood may impact prediction of force transmission and, thus, should be considered when modeling the action of the extensor apparatus. Across the extensor hood, tangent modulus values were substantially smaller than values reported for other soft tissues, such as the Achilles tendon and knee ligaments, while ultimate strains were much greater. Thus, the tissue in the extensor apparatus seems to have greater elasticity, which should be modeled accordingly. [ABSTRACT FROM AUTHOR]

Purpose: The most appropriate procedure for surgical treatment of severe acromioclavicular (AC) joint dislocation was still not clear. The purpose of this study is to evaluate the outcomes of coracoclavicular (CC) reconstruction with ligament augmentation and reconstruction system (LARS) artificial ligaments for the treatment of acute complete AC joint dislocation. Methods: Twenty-four patients (16 male and 8 female, ages ranged from 21 to 45) with acute complete AC joint dislocations were treated with CC reconstruction using LARS artificial ligaments. All these dislocations were unstable injuries. Clinical evaluation was used by the Constant scores and VAS. The radiographic evaluation consisted of Zanca radiographs for bilateral AC joint and axillary radiographs for the injured shoulder. Results: All patients had follow-up times of 36 months (range 6-60). The Constant scores rose from 62.3 ± 6.9 preoperatively to 94.5 ± 9.3 at final evaluation ( P < 0.05). Preoperative VAS scores were 5.1 ± 1.7, and the VAS scores at the last review were 0.7 ± 1.4 ( P < 0.05). Follow-up radiographs showed anatomical reduction in 20 patients and slight loss of reduction in 4 patients. Calcification of CC ligament in 4 patients, degenerative change around the AC joint in 2 patient and clavicular osteolysis around screws in one patient were found. Conclusions: LARS artificial ligament for reconstruction of CC can provide immediate stability and allow early shoulder mobilization with good functional results and few complications. This procedure was an effective and safe method to treat grade III and more AC joint dislocations. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Loss of ligament graft tension in early postoperative stages following anterior cruciate ligament (ACL) reconstruction can come from a variety of factors, with slow graft integration to bone being widely viewed as a chief culprit. Toward an off-the-shelf ACL graft that can rapidly integrate to host tissue, we have developed a silk-based ACL graft combined with a tricalcium phosphate (TCP)/polyether ether ketone anchor. In the present study we tested the safety and efficacy of this concept in a porcine model, with postoperative assessments at 3months (n=10) and 6months (n=4). Biomechanical tests were performed after euthanization, with ultimate tensile strengths at 3months of ~370N and at 6months of ~566N - comparable to autograft and allograft performance in this animal model. Comprehensive histological observations revealed that TCP substantially enhanced silk graft to bone attachment. Interdigitation of soft and hard tissues was observed, with regenerated fibrocartilage characterizing a transitional zone from silk graft to bone that was similar to native ligament bone attachments. We conclude that both initial stability and robust long-term biological attachment were consistently achieved using the tested construct, supporting a large potential for silk-TCP combinations in the repair of the torn ACL. [ABSTRACT FROM AUTHOR]

Modeling ligaments as three-dimensional strings is a popular method for in vivo estimation of ligament length. The purpose of this study was to develop an algorithm for automated generation of non-penetrating strings between insertion points and to evaluate its feasibility for estimating length changes of the medial patellofemoral ligament during normal knee flexion. Three-dimensional knee models were generated from computed tomography (CT) scans of 10 healthy subjects. The knee joint under weight-bearing was acquired in four flexion positions (0°-120°). The path between insertion points was computed in each position to quantify string length and isometry. The average string length was maximal in 0° of flexion (64.5 ± 3.9 mm between femoral and proximal patellar point; 62.8 ± 4.0 mm between femoral and distal patellar point). It was minimal in 30° (60.0 ± 2.6 mm) for the proximal patellar string and in 120° (58.7 ± 4.3 mm) for the distal patellar string. The insertion points were considered to be isometric in 4 of the 10 subjects. The proposed algorithm appears to be feasible for estimating string lengths between insertion points in an automatic fashion. The length measurements based on CT images acquired under physiological loading conditions may give further insights into knee kinematics. [ABSTRACT FROM AUTHOR]

For recurrent patellar dislocation, reconstruction of the medial patellofemoral ligament (MPFL) with replacement autografts has often been performed but with only little data on the tensile properties of the MPFL to guide graft selection. With its complex anatomy and geometry, these properties are difficult to obtain. In this study, we showed how the orientation of the femur-MPFL-patella complex (FMPC) during uniaxial tensile testing can have a significant effect on its structural properties. Twenty two FMPCs were isolated from porcine stifle joints and randomly assigned to two groups of 11 each. For the first group, the specimens were loaded to failure with the patella oriented 30 degrees away from the direction of the applied load to mimic its orientation in situ, called natural orientation. In the second group, the patella was aligned in the direction of the tensile load, called non-natural orientation. The stiffness for the natural orientation group was 65 7 13 N/mm, 32% higher than that for the non-natural orientation group (50 7 17 N/mm; p < 0.05). The ultimate loads were 438 7 128 N and 386 7 136 N, respectively (p > 0.05). Ten out of 11 specimens in the natural orientation group failed at the femoral attachment (the narrowest portion of the MPFL) compared to 6 out of 11 in the non-natural orientation group. Our findings suggest that the specimen orientation that mimics the in-situ loading conditions of the MPFL should be used to obtain more representative data for the structural properties of the FMPC. [ABSTRACT FROM AUTHOR]

Abstract: Intercarpal instability is often secondary to a scapholunate interosseous (SLIO) ligament lesion. Its reconstruction is thus essential. Classical capsulodesis techniques fix the scaphoid in extension and do not reproduce the physiologic ligamentous isometry of the wrist. The authors use the technique of Viegas, which seems to respect this isometry: the dorsal intercarpal ligament is re-inserted dorsally to reattach the capsule on the dorsal SLIO and to reinforce it. Between 2006 and 2010, 25 wrists were operated on in 12 men and 12 women of mean age 38years. All patients presented with pain often associated with loss of power, decreased mobility or a debilitating click. The mean follow-up was 26months. Postoperative and preoperative data were compared. Flexion/extension range increased by 2.6°, radioulnar deviation increased by 21.1°. Grip strength increased by 8.7kgf. Pain decreased by 3 points on the VAS and the PRWE improved by 59 points. We observed four CRPS, one EPL lesion and one case of superficial track pin infection. We got eleven excellent results, nine good, two moderate and three bad, two of which were re-operated. Viegas’ capsulodesis does not present major technical difficulty. The results show no stiffness in flexion/extension. There was evident improvement in radioulnar deviation, grip strength, pain and PRWE scores. This technique provides effective treatment for a difficult or irreparable lesion of the SLIO ligament, without fixed carpal instability corresponding to Geissler arthroscopic stages 2 to 4 and Garcia-Elias stages 3 and 4. The capsulodesis produces an effective stabilization without stiffness. Precautions should be undertaken to avoid CRPS and pin complications. [Copyright &y& Elsevier]

ABSTRACT Background Chronic posterolateral rotatory instability occurs as a result of disruption of the lateral ulnar collateral ligament of the elbow. It is usually treated by ligament reconstruction using an autogenous graft. We present our experience of reconstruction with the use of a synthetic polyester ( LARS ®; Ligament Advanced Reinforcement System; Surgical Implants and Devices, Arc-sur-Tille, France) ligament and discuss the advantages of this technique. Methods Ten consecutive cases of lateral ligament reconstruction using a LARS® ligament were reviewed. The mean age at the time of surgery was 30.2 years. The mean duration of instability symptoms preoperatively was 32.4 months. Three patients had generalized hyperlaxity. Three patients had previously undergone an unsuccessful autogenous graft reconstruction. Results The mean postoperative follow-up was 27 months. At review, seven of the 10 patients had stable elbows with no feelings of recurrent instability. This included two of the patients with generalized hyperlaxity. The mean postoperative arc of flexion/extension was 13° to 137°. The mean Mayo Elbow Performance Score was 87.5. Conclusions The use of a synthetic ligament for reconstruction of posterolateral rotatory instability of the elbow provides satisfactory stability. It avoids the associated morbidity of using an autograft, appears to be well tolerated and is particularly valuable in the treatment of complex generalized hyperlaxity problems. [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]

The article discusses a study which examined the piezoelectricity of the helical poly-L-lactic acid (PLLA) fibers using in-vitro lock-in amplifier system. Study authors found that the formation of osseous tissue around helical PLLA fibers was more significant than around non-helical control fibers. They concluded that helical PLLA fiber may be useful for surgical suture or as an artificial ligament.

Purpose: The aim of this study was to review patients that underwent ACL reconstruction with the LARS™ ligament in the First Orthopaedic Division of Pisa University during the period between January 2003 and December 2005. Methods: Twenty-six patients were reviewed with an average follow-up of 95.3 months (7.9 years). The review protocol was articulated in three phases: (1) a subjective evaluation using three grading scales: VAS, KOOS and the Cincinnati knee rating scale, (2) a clinical and objective evaluation, and (3) a biomechanical evaluation of the knee stability. Results: A global positive result was obtained in 92.3 % of the patients (16 optimal results and eight good results), with a fast functional recovery and a high knee stability. A global poor result was reported in two cases. In our series we did not record cases of infection or knee synovitis. We recorded only one case of mechanical graft failure. The results obtained from our study are encouraging and similar to those in the literature. Conclusions: We conclude that the LARS™ ligament can be considered a suitable option for ACL reconstruction in carefully selected cases, especially for older patients needing a fast functional recovery. [ABSTRACT FROM AUTHOR]

An alteration in stress/strain distribution within periodontal ligament (PDL) occurs when the tooth is mechanical stimulated in orthodontic treatment. The majority of previous finite element studies were confined to a static evaluation on initial loading status, and a dynamic long-term analysis was rarely performed in orthodontics. The present study sought to analyze the stress distribution patterns within tooth root, PDL, and alveolar bone during dynamic canine tipping and bodily movement with three-dimensional finite element method in four consecutive therapeutic weeks. We observed that the highest stress was on root surface, secondly alveolar bone, and finally, PDL for either tipping or bodily movement. Throughout the PDL and root surface, the highest stress was always around the cervical area in both patterns of movement through four phases. Moreover, a lower and more uniform stress distribution was produced during bodily movement compared with tipping movement. These results indicated that canine translation might be healthier for periodontal tissue than tipping movement; the cervical region bore a greater load and might also be a susceptible area for tissue damage (except for the apex) regardless of movement pattern. [ABSTRACT FROM AUTHOR]

BACKGROUND: Introduction of a new generation of artificial ligaments for ACL reconstruction, the Ligament Augmentation and Reconstruction System (LARS), gives promising clinical results [1]. The current literature supports the use of LARS from short to medium term. To go even further to improve the biocompatibility of this biomaterial, poly(sodium styrene sulfonate) (polyNaSS) was grafted onto its surface. Studies using sheep animal model showed improvement of knee functionalities with this grafted artificial ligament and a better adhesion of human cell lines.OBJECTIVES: To better understand this in vivo improvement of integration with the bioactivated artificial prosthesis, in vitro studies were leaded using human ligament fibroblasts.METHODS: Human ligament fibroblasts isolated from human ruptured ACL were amplified and seeded onto poly(NaSS) grafted and non-grafted PET scaffold (Lars ligament) under standard culture conditions. Cellularized fibers were observed under scanning electron microscopy and histological and immunohistological studies were performed.RESULTS: Cells are localized around the grafted PET fibers of the bioactive ligament and penetrate in the scaffold. On ungrafted fibers, cells stay around the scaffold. On grafted fibers, collagen I appears strongly organized whereas is thin and dispersed on non grafted fibers. Finally, grafting altered localization of decorin.CONCLUSIONS: PolyNaSS grafting enhances human ligament fibroblast organisation in vitro in contact with biomaterial and improves collagen and decorin deposits around fibers. [ABSTRACT FROM AUTHOR]