Introduction. The objective of the work is construction of a multi-bioactive scaffold based on that allows a space/time control over the regeneration of damaged bones by Medication-Related Osteonecrosis of the Jaw using a minimal invasive approach based on the injection of the fast-degrading pro neuro and angiogenic ELR (Elastin-Like Recombinamers) based hydrogels. Method. Chemical crosslinking facilitated the creation of multi-bioactive scaffolds using ELRs with reactive groups. Cell-loaded multi-bioactive scaffolds, prepared and incubated, underwent evaluation for adhesion, proliferation, angiogenic, and neurogenic potential. In vitro assessments utilized immunofluorescence staining and ELISA assays, while live-recorded monitoring and live-dead analysis ensured cytocompatibility. In rat and
Introduction. The healing of rotator cuff injuries poses significant challenges, primarily due to the complexity of recreating the native tendon-to-bone interface, characterized by highly organized structural and compositional gradients. Addressing this, our innovative approach leverages bioprinted living tissue constructs, incorporating layer-specific growth factors (GFs) to facilitate enthesis regeneration. This method aims to guide in situ zonal differentiation of stem cells, closely mirroring the natural enthesis tissue architecture. Method. Our strategy involves the utilization of advanced bioprinting technology to fabricate living tissue constructs. These constructs are meticulously designed with embedded microsphere-based delivery carriers, ensuring the sustained release of tenogenic, chondrogenic, and osteogenic growth factors. This layer-specific release mechanism is tailored to promote the precise differentiation of stem cells across different regions of the construct, aligning with the gradient nature of enthesis tissues. Result. In vitro studies demonstrated that our layer-specific tissue constructs significantly outperformed basal constructs without GFs, achieving region-specific differentiation of stem cells. More critically, in a
This study aimed to demonstrate the promoting effect of elastic fixation on fracture, and further explore its mechanism at the gene and protein expression levels. A closed tibial fracture model was established using 12 male Japanese white rabbits, and divided into elastic and stiff fixation groups based on different fixation methods. Two weeks after the operation, a radiograph and pathological examination of callus tissue were used to evaluate fracture healing. Then, the differentially expressed proteins (DEPs) were examined in the callus using proteomics. Finally, in vitro cell experiments were conducted to investigate hub proteins involved in this process.Aims
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Bacteriophages infect, replicate inside bacteria, and are released from the host through lysis. Here, we evaluate the effects of repetitive doses of the For the haematogenous infection, Aims
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To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration. The OCD lesion was created on the trochlear groove of left articular cartilage of femur per rat (40 rats in total). The experimental groups were Sham, OCD, and ESWT (0.25 mJ/mm2, 800 impulses, 4 Hz). The animals were euthanized at 2, 4, 8, and 12 weeks post-treatment, and histopathological analysis, micro-CT scanning, and immunohistochemical staining were performed for the specimens.Aims
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The April 2024 Foot & Ankle Roundup360 looks at: Safety of arthroscopy combined with radial extracorporeal shockwave therapy for osteochondritis of the talus; Bipolar allograft transplantation of the ankle; Identifying risk factors for osteonecrosis after talar fracture; Balancing act: immediate versus delayed weightbearing in ankle fracture recovery; Levelling the field: proximal supination osteotomy’s efficacy in severe and super-severe hallux valgus; Restoring balance: how adjusting the tibiotalar joint line influences movement after ankle surgery.
Aims. Fracture-related infection (FRI) is commonly classified based on the time of onset of symptoms. Early infections (< two weeks) are treated with debridement, antibiotics, and implant retention (DAIR). For late infections (> ten weeks), guidelines recommend implant removal due to tolerant biofilms. For delayed infections (two to ten weeks), recommendations are unclear. In this study we compared infection clearance and bone healing in early and delayed FRI treated with DAIR in a
Prosthetic joint infections represent complications connected to the implantation of biomedical devices, they have high incidence, interfere with osseointegration, and lead to a high societal burden. The microbial biofilm, which is a complex structure of microbial cells firmly attached to a surface, is one of the main issues causing infections. Biofilm- forming bacteria are acquiring more and more resistances to common clinical treatments due to the abuse of antibiotics administration. Therefore, there is increasing need to develop alternative methods exerting antibacterial activities against multidrug-resistant biofilm-forming bacteria. In this context, metal-based coatings with antimicrobial activities have been investigated and are currently used in the clinical practice. However, traditional coatings exhibit some drawbacks related to the insufficient adhesion to the substrate, scarce uniformity and scarce control over the toxic metal release reducing their efficacy. Here, we propose the use of antimicrobial silver-based nanostructured thin films to discourage bacterial infections. Coatings are obtained by Ionized Jet Deposition, a plasma-assisted technique that permits to manufacture films of submicrometric thickness having a nanostructured surface texture, allow tuning silver release, and avoid delamination. To mitigate interference with osseointegration, here silver composites with bone apatite and hydroxyapatite were explored. The antibacterial efficacy of silver films was tested in vitro against gram- positive and gram-negative species to determine the optimal coatings characteristics by assessing reduction of bacterial viability, adhesion to substrate, and biofilm formation. Efficacy was tested in an in vivo
Prosthetic joint infections represent complications connected to the implantation of biomedical devices, they have high incidence, interfere with osseointegration, and lead to a high societal burden. The microbial biofilm, which is a complex structure of microbial cells firmly attached to a surface, is one of the main issues causing infections. Biofilm- forming bacteria are acquiring more and more resistances to common clinical treatments due to the abuse of antibiotics administration. Therefore, there is increasing need to develop alternative methods exerting antibacterial activities against multidrug-resistant biofilm-forming bacteria. In this context, metal-based coatings with antimicrobial activities have been investigated and are currently used in the clinical practice. However, traditional coatings exhibit some drawbacks related to the insufficient adhesion to the substrate, scarce uniformity and scarce control over the toxic metal release reducing their efficacy. Here, we propose the use of antimicrobial silver-based nanostructured thin films to discourage bacterial infections. Coatings are obtained by Ionized Jet Deposition, a plasma-assisted technique that permits to manufacture films of submicrometric thickness having a nanostructured surface texture, allow tuning silver release, and avoid delamination. To mitigate interference with osseointegration, here silver composites with bone apatite and hydroxyapatite were explored. The antibacterial efficacy of silver films was tested in vitro against gram- positive and gram-negative species to determine the optimal coatings characteristics by assessing reduction of bacterial viability, adhesion to substrate, and biofilm formation. Efficacy was tested in an in vivo
Healing after bone fracture is assessed by frequent radiographs, which expose patients to radiation and lacks behind biological healing. This study aimed to investigate whether the electrical impedance using electrical impedance spectroscopy correlated to quantitative scores of bone healing obtained from micro-CT and mechanical bending test. Eighteen rabbits were subjected to tibial fracture that was stabilized with external fixator. Two electrodes were positioned, one electrode placed within the medullary cavity and the other on the lateral cortex, both three millimeters from the fracture site. Impedance was measured daily across the fracture site at a frequency range of 5 Hz to 1 MHz. The animals were divided into three groups with different follow-up time: 1, 3 and 6 weeks for micro-CT (Bone volume/tissue volume (BV/TV, %)) and mechanical testing (maximum stress (MPa), failure energy (kJ/cm3), young modulus (Mpa)). There was a statistically significant correlation between last measured impedance at 5 Hz frequency immediately prior to euthanasia and BV/TV of callus (−0.68, 95%CI: (−0.87; −0.31)). Considering the mechanical testing with three-point bending, no significant correlation was found between last measured impedance at 5 Hz frequency immediately prior to euthanasia and maximum stress (−0.35, 95%CI: (−0.70; 0.14)), failure energy (−0.23, 95%CI: (−0.63; 0.26)), or young modulus (−0.28, 95%CI: (−0.66; 0.22)). The significant negative correlation between impedance and BV/TV might indicate that impedances correlate with the relative bone volume in the callus site. The lack of correlation between impedance and mechanical parameters when at the same time observing a correlation between impedance and days since operation (0-42 days), might indicate that the impedance can measure biological changes at an earlier time point than rough mechanical testing.
Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration. A total of 24 male New Zealand white rabbits were divided into four groups according to the experimental materials. Allogenic adipose-derived mesenchymal stem cells (AMSCs) were cultured and seeded evenly in the collagen/chitosan sheet to form cell sheet as periosteum. Simultaneously, allogenic AMSCs were seeded onto alginate beads and were cultured to differentiate to endothelial-like cells to form vascularized bone construct (VBC). The cell sheet was wrapped onto VBC to create a vascularized bone-periosteum construct (VBPC). Four different experimental materials – acellular construct, VBC, non-vascularized bone-periosteum construct, and VBPC – were then implanted in bilateral L4-L5 intertransverse space. At 12 weeks post-surgery, the bone-forming capacities were determined by CT, biomechanical testing, histology, and immunohistochemistry staining analyses.Aims
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Aim. The time to onset of symptoms after fracture fixation is still commonly used to classify fracture-related infections (FRI). Early infections (<2 weeks) can often be treated with debridement, systemic antibiotics, irrigation, and implant preservation (DAIR). Late infections (>10 weeks) typically require implant removal as mature, antibiotic-tolerant biofilms have formed. However, the recommendations for delayed infections (2–10 weeks) are not clearly defined. Here, infection healing and bone healing in early and delayed FRI is investigated in a
Arthroscopic microfracture is a conventional form of treatment for patients with osteochondritis of the talus, involving an area of < 1.5 cm2. However, some patients have persistent pain and limitation of movement in the early postoperative period. No studies have investigated the combined treatment of microfracture and shortwave treatment in these patients. The aim of this prospective single-centre, randomized, double-blind, placebo-controlled trial was to compare the outcome in patients treated with arthroscopic microfracture combined with radial extracorporeal shockwave therapy (rESWT) and arthroscopic microfracture alone, in patients with ostechondritis of the talus. Patients were randomly enrolled into two groups. At three weeks postoperatively, the rESWT group was given shockwave treatment, once every other day, for five treatments. In the control group the head of the device which delivered the treatment had no energy output. The two groups were evaluated before surgery and at six weeks and three, six and 12 months postoperatively. The primary outcome measure was the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale. Secondary outcome measures included a visual analogue scale (VAS) score for pain and the area of bone marrow oedema of the talus as identified on sagittal fat suppression sequence MRI scans.Aims
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Treatment of bone infection often includes a burdensome two-stage revision. After debridement, contaminated implants are removed and replaced with a non-absorbable cement spacer loaded with antibiotics. Weeks later, the spacer is exchanged with a bone graft aiding bone healing. However, even with this two-stage approach infection persists. In this study, we investigated whether a novel 3D-printed, antibiotic-loaded, osteoinductive calcium phosphate scaffold (CPS) is effective in single-stage revision of an infected non-union with segmental bone loss in rabbits. A 5 mm defect was created in the radius of female New Zealand White rabbits. The bone fragment was replaced, stabilized with cerclage wire and inoculated with Staphylococcus aureus (MSSA). After 4 weeks, the infected bone fragment was removed, the site debrided and a spacer implanted. Depending on group allocation, rabbits received: 1) PMMA spacer with gentamycin; 2) CPS loaded with rifampin and vancomycin and 3) Non-loaded CPS. These groups received systemic cefazolin for 4 weeks after revision. Group 4 received a loaded CPS without any adjunctive systemic therapy (n=12 group1-3, n=11 group 4). All animals were euthanized 8 weeks after revision and assessed by quantitative bacteriology or histology. Covariance analysis (ANCOVA) and multiple regression were performed. All animals were culture positive at revision surgery. Half of the animals in all groups had eliminated the infection by end of study. In a historical control group with empty defect and no systemic antibiotic treatment, all animals were infected at euthanasia. There was no significant difference in CFU counts between groups at euthanasia. Our results show that treating an osteomyelitis with segmental bone loss either with CPS or PMMA has a similar cure rate of infection. However, by not requiring a second surgery, the use of CPS may offer advantages over non-resorbable equivalents such as PMMA.
In chronically infected fracture non-unions, treatment requires extensive debridement to remove necrotic and infected bone, often resulting in large defects requiring elaborate and prolonged bone reconstruction. One approach includes the induced membrane technique (IMT), although the differences in outcome between infected and non-infectious aetiologies remain unclear. Here we present a new rabbit humerus model for IMT secondary to infection, and, furthermore, we compare bone healing in rabbits with a chronically infected non-union compared to non-infected equivalents. A 5 mm defect was created in the humerus and filled with a polymethylmethacrylate (PMMA) spacer or left empty ( All the animals from the infected group were culture positive during the first revision surgery (mean 3×105 CFU/animal, We developed a preclinical
There is no optimal therapy to stop or cure chondral degeneration in osteoarthritis (OA). Beside cartilage, subchondral bone is involved. The often sclerotic bone is mechanically less solid which in turn influences negatively chondral quality. Microfracturing as therapeutic technique aims to enhance bone quality but is applied only in smaller cartilage lesions. The osteoproliferative properties of Magnesium (Mg) have been shown repeatedly1-3. The present study examined the influence of micro-scaled Mg cylinders compared to sole drilling in an OA model. Ten New Zealand White rabbits underwent anterior crucial ligament transection. During 12 weeks after surgery, the animals developed OA as previously described4. In a second surgery, half of the animals received 20 drill holes (ø 0.5mm) and the other half received 20 drill holes, which were additionally filled with one Mg cylinder each. Extracapsular plication was performed in all animals. During the follow-up of 8 weeks three µ-computed tomographic (µCT) scans were performed: immediately after surgery and after four and eight weeks. Changes of bone volume, trabecular thickness and bone density were calculated and compared. µCT evaluation showed an increase in bone volume and trabecular thickness in both groups. This increase was significantly higher in rabbits which received Mg cylinders showing thrice as high values for both parameters (bone volume: Mg group +44.5%, drilling group +15.1%, p≤0.025; trabecular thickness: Mg group +53.2%, drilling group +16.9%, p≤0.025). Also bone density increased in both groups, but on a distinctly lower level and with no significant difference. Although profound higher bone volume was found after implantation of Mg cylinders, µCT showed similar levels of bone density indicating adequate bone quality in this OA model. Macroscopic and histological evaluation of cartilage condition have to reveal possible impact on OA progression. Additionally, current examination implement different alloys and influence on lameness.
Osteoarthritis (OA), the most prevalent chronic joint disease, represents a relevant social and economic burden worldwide. Human umbilical cord mesenchymal stem cells (HUCMSCs) have been used for injection into the joint cavity to treat OA. The aim of this article is to clarify whether Huc-MSCs derived exosomes could inhibit the progression of OA and the mechanism in this process. A rabbit OA model was established by the transection of the anterior cruciate ligament. The effects of HUCMSCs or exosomes derived from HUCMSCs on repairing articular cartilage of knee osteoarthritis was examined by micro-CT. Immunohistochemical experiments were used to confirm the expression of relevant inflammatory molecules in OA. In vitro experiments, Transwell assay was used to assess the migration of macrophages induced by TNF-a. Results showed that a large number of macrophages migrated in arthcular cavity in OA model in vivo, while local injection of HUCMSCs and exosomes did repair the articular cartilage. Immunohistochemical results suggested that the expression of CCL2 and CD68 in the OA
In this study, we developed biocompatible adhesive which enables implanted chondrogenic-enhanced hASCs being strongly fixed to the lesion site of defected cartilage. The bioengineered mussel adhesive protein (MAP) was produced and purified using a bacterial expression system as previously reported. The cell encapsulated coacervate was formulated with two polyelectrolyte, the MAP and 723kDa hyaluronic acid (HA). MAP formed liquid microdroplets with HA and subsequently gelated into microparticles, which is highly viscous and strongly adhesive. The MAP with chondro-induced hASCs were implanted on the osteochondral defect created in the patellar groove/condyle of OA-induced rabbits.
As has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA). Experimental knees were immobilized for either four weeks (72 mice) or eight weeks (72 mice), followed by a remobilization period of zero weeks (24 mice), two weeks (24 mice), or four weeks (24 mice) after suture removal. Half of the experimental knees also received an intra-articular injury. Biomechanical data were collected to measure passive extension angle (PEA). Histological data measuring area and thickness of posterior and anterior knee capsules were collected from knee sections.Aims
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Infection in orthopedics is a challenge, since it has high incidence (rates can be up to 15-20%, also depending on the surgical procedure and on comorbidities), interferes with osseointegration and brings severe complications to the patients and high societal burden. In particular, infection rates are high in oncologic surgery, when biomedical devices are used to fill bone gaps created to remove tumors. To increase osseointegration, calcium phosphates coatings are used. To prevent infection, metal- and mainly silver-based coatings are the most diffused option. However, traditional techniques present some drawbacks, including scarce adhesion to the substrate, detachments, and/or poor control over metal ions release, all leading to cytotoxicity and/or interfering with osteointegration. Since important cross-relations exist among infection, osseointegration and tumors, solutions capable of addressing all would be a breakthrough innovation in the field and could improve clinical practice. Here, for the first time, we propose the use antimicrobial silver-based nanostructured thin films to simultaneously discourage infection and bone metastases. Coatings are obtained by Ionized Jet Deposition, a plasma-assisted technique that permits to manufacture films of submicrometric thickness having a nanostructured surface texture. These characteristics, in turn, allow tuning silver release and avoid delamination, thus preventing toxicity. In addition, to mitigate interference with osseointegration, here silver composites with bone apatite are explored. Indeed, capability of bone apatite coatings to promote osseointegration had been previously demonstrated in vitro and in vivo. Here, antibacterial efficacy and biocompatibility of silver-based films are tested in vitro and in vivo. Finally, for the first time, a proof-of-concept of antitumor efficacy of the silver-based films is shown in vitro. Coatings are obtained by silver and silver-bone apatite composite targets. Both standard and custom-made (porous) vertebral titanium alloy prostheses are used as substrates. Films composition and morphology depending on the deposition parameters are investigated and optimized. Antibacterial efficacy of silver films is tested in vitro against gram+ and gram- species (E. coli, P. aeruginosa, S. aureus, E. faecalis), to determine the optimal coatings characteristics, by assessing reduction of bacterial viability, adhesion to substrate and biofilm formation. Biocompatibility is tested in vitro on fibroblasts and MSCs and, in vivo on rat models. Efficacy is also tested in an in vivo