Metal Screws Research Articles

THE COMPUTER MODELING STUDY OF INTERACTIONS BETWEEN CONTACT SURFACES OF METAL OR POLIMERIC SCREWS AND CORTICAL BONE TISSUE

The continuous growth of fracture rates and surgeries with the use of screws requires modern approaches to improve treatment results. The interaction between a screw and bone tissue is one of the critical factors that affects the stability of a fracture and remains not thoroughly researched until now. The computer modeling method allows for studying precisely the strains and deformities in the contact areas of metal screws, polymeric screws, and cortical bone.Material and methods. The computer modeling was performed in Autodesk Fusion 360 for biomechanical interactions of 3.5 mm AO screws made of stainless steel and polyamide-12 (P-12) with monocortical diaphyseal part of long tubular bone. The static stress study was performed for different loads applied in the pull-out direction with the bonded contact used between the screw and the bone. The displacement and strains were revealed in different parts of the screw thread and surrounding bone tissue for the force applied along the screw axis in the range from 100 N to 1000 N.Results. The increase of the force resulted in stress and strains in the screw and surrounding bone tissue, and the maximum force values can lead to unstable fixation. It was determined that polymeric P-12 screws in all study cases were affecting the bone with less contact pressure than metal screws. In the superficial bone areas this difference was more significant – 24.8 %, and in the deep bone areas it was 8.9 %. The areas of von Mises stress in both superficial and deep parts of polymeric screws were in the range from 1.414 MPa to 20.74 MPa which was lower than that of metal screws (3.484 MPa to 56.24 MPa).Conclusions. Polymeric P-12 screws will fix bone fractures better under low intensive but long-lasting loads, as their destructive effect on bone tissue around screws will be less than of metal ones. On the other hand, metal screws will have the advantage to resist the short lasting but intensive “peak” loads. The less stress areas in the polymeric screw can somehow compensate the lower mechanical strength parameters of P-12 material.Perspective of further research. The obtained results can be taken into account during orthopedics surgeries when screws are used for fixation, as well as for further biomechanical studies.

Management of pediatric ankle fractures: comparison of biodegradable PLGA implants with traditional metal screws.

The relevance of biodegradable implants has gained more importance in modern clinical practice. The study aimed to evaluate the effects and outcomes of ankle fracture treatment with absorbable implants compared to metal screws. These implants are made from poly l-lactic-co-glycolic acid (PLGA), however, there are several other materials available on the market. In a retrospective review, a total of 128 patients were under observation, with distal tibial fracture types ranging from Salter-Harris II-IV. In the absorbable group, patients were treated with the implants (n = 76). The metal group included patients treated with titanium or steel screws (n = 52). The extremities were placed in a cast for six weeks after surgery and were utilized for another 6-8 weeks. Patients were followed up for 12-30 months and were evaluated accordingly. The authors examined several aspects such as age, gender, open or closed repair, mechanism of injury, length of hospitalization, type of fracture, time of recovery, and complications. There were no statistically significant differences between the groups regarding demographic qualities, such as age, type of fracture, side of injury, and length of cast application (p > 0.05 in all cases). Out of 76 patients in the PLGA group, only two presented with complications, so reoperation took place. The rest healed without complications or refractures. Two of those treated with metal screws (n = 52) had minor, and four had major complications with reoperation. In pediatric cases, PLGA implants may present excellent results for treating ankle fractures. They do not disturb the growth plate and do not require reoperation. For this reason, they reduce the burden on the patient and the healthcare provider while simultaneously decreasing the risk of complications, such as infections or problems due to general anesthesia.

Comparison of surgical outcomes between bioabsorbable and metal screw fixation for distal tibial physeal fracture in children and adolescent.

This study aimed to compare the surgical outcomes between bioabsorbable and metal screw fixation for distal tibial physeal fracture in children and adolescents, radiographically and clinically. This study included consecutive 67 children and adolescents who underwent open reduction and internal fixation using metal or bioabsorbable screws for the distal tibia physeal fracture. All patients underwent preoperative radiographs, three-dimensional computed tomography scans, and postoperative follow-up teleradiogram. Patients were divided into metal (N = 40) and bioabsorbable groups (N = 27). We compared the surgical outcomes between the two groups in terms of clinical and radiographic outcomes, length of hospital stays, and medical cost. Follow-up duration were significantly longer in the metal group than that in the bioabsorbable group. There was no significant difference in the incidence of growth arrest after surgery and the scores of the Oxford Ankle and Foot Questionnaire between the two groups. However, the total hospital stay was significantly longer in the metal group (5.2 ± 4.8 days) compared to the bioabsorbable group (2.6 ± 0.5 days). Medical costs were significantly higher in the bioabsorbable group than in the metal group with a difference of 397 US dollars. The use of bioabsorbable screws exhibited therapeutic effects equivalent to that of metal screws for pediatric distal tibia physeal fractures regarding clinical and radiological outcomes. Moreover, it had the advantage of avoiding the need for repeated general anesthesia and secondary operation for implant removal. Therefore, the use of bioabsorbable screws may be a favourable surgical option for treating pediatric fractures.

Radiographic Tibial Tunnel Assessment After Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autografts and Biocomposite Screws: A Prospective Study With 10-Year Follow-up.

Biocomposite screws reportedly provide equivalent graft fixation in anterior cruciate ligament reconstruction (ACLR) to metallic screws while simplifying subsequent imaging and surgery. One purported complication of biocomposite screws is paradoxical tunnel widening. Previous studies on beta-tricalcium phosphate screws have only reported outcomes at short- and midterm follow-up. To radiographically assess the tibial tunnel 10 years after ACLR using hamstring tendon autografts and biocomposite interference screws in anatomic single-bundle (SB) and double-bundle (DB) methods. Case series; Level of evidence, 4. Of the 105 initially recruited patients, 61 (58%) completed all follow-up evaluations for inclusion in this long-term study. A total of 26 patients received anatomic SB ACLR and 35 patients received DB ACLR with biocomposite interference screws containing beta-tricalcium phosphate in the tibia. Weightbearing anteroposterior and lateral radiographs of the index knee were taken in the early postoperative period and at 2, 5, and 10 years postoperatively; computed tomography (CT) imaging was performed at 10-year follow-up. Subjective and objective clinical assessments were recorded preoperatively and at 10-year follow-up. The mean follow-up period was 122 months. In 76% of radiographs in the SB group, the width of the tibial tunnel had not increased at 10 years compared with the early postoperative period. The mean tibial tunnel volume on CT in the SB group was 2.04 cm3 (± 0.85 cm3). In the DB group, the posterolateral tunnel width had not increased in 69% of radiographs; the same was found in 63% of radiographs for the anteromedial tunnel at 10-year follow-up. The mean posterolateral tunnel volume on CT was 2.04 cm3 (±1.92 cm3) and the mean anteromedial tunnel volume was 1.38 cm3 (±0.54 cm3). There was no correlation between tunnel widths and KT-1000 arthrometer assessments. There was a moderate but statistically significant correlation between SB tibial tunnel volume on CT imaging and KT-1000 arthrometer anterior 134 N side-to-side difference (r = 0.45; P = .039). Most patients' tibial tunnels had not increased on 1 or both radiographic views at 10-year follow-up compared with the early postoperative period after ACLR using biocomposite interference screws, with no obvious negative effect on outcomes. However, the tunnels were still visible in most patients at 10 years on standard radiographs and CT imaging.

Review of Metal Screw Extrusion: State of the Art and Beyond

Metal screw extrusion (MSE) is a continuous, solid-state forming method utilizing an inherently high degree of deformation to consolidate fragmented input materials into a solid bulk by breaking their oxide skins. Severe plastic deformation with equivalent strain in the range of 10–20 can be achieved depending on set process parameters. Rigorous mixing can be employed to form sophisticated materials like bulk composites, nanocomposites, particle-reinforced metals, and fine-grained materials. Furthermore, the inherent solid-state processing is well suited for recovery of difficult-to-recycle materials. A range of non-ferrous materials has been manufactured by MSE and further characterized in terms of microstructural evolution and mechanical and functional properties. Furthermore, MSE has been studied in terms of flow, accumulated strain, and environmental impact. The following review aims to critically highlight the existing work performed on MSE, compare it to existing and emerging technologies as well as explore future development and possible applications. MSE has the potential to be utilized for numerous commercial applications. To realize industrial use of MSE, key aspects of the process and the influence of processing parameters on the resulting product must be understood.

Multilayer Gelatin-Supported BMP-9 Coating Promotes Osteointegration and Neo-Bone Formation at the n-CDHA/PAA Composite Biomaterial-Bone Interface.

The development of biomaterials capable of accelerating bone wound repair is a critical focus in bone tissue engineering. This study aims to evaluate the osteointegration and bone regeneration potential of a novel multilayer gelatin-supported Bone Morphogenetic Protein 9 (BMP-9) coated nano-calcium-deficient hydroxyapatite/poly-amino acid (n-CDHA/PAA) composite biomaterials, focusing on the material-bone interface, and putting forward a new direction for the research on the interface between the coating material and bone. The BMP-9 recombinant adenovirus (Adenovirus (Ad)-BMP-9/Bone Marrow Mesenchymal Stem Cells (BMSc)) was produced by transfecting BMSc and supported using gelatin (Ad-BMP-9/BMSc/Gelatin (GT). Multilayer Ad-BMP-9/BMSc/GT coated nano-calcium deficient hydroxyapatite/polyamino acid (n-CDHA/PAA) composite biomaterials were then prepared and co-cultured with MG63 cells for 10 days, with biocompatibility assessed through microscopy, Cell Counting Kit-8 (CCK-8), and alkaline phosphatase (ALP) assays. Subsequently, multilayer Ad-BMP-9/BMSc/GT coated n-CDHA/PAA composite biomaterial screws were fabricated, and the adhesion of the coating to the substrate was observed using scanning electron microscopy (SEM). In vivo studies were conducted using a New Zealand White rabbit intercondylar femoral fracture model. The experimental group was fixed with screws featuring multilayer Ad-BMP-9/BMSc/GT coatings, while the control groups used medical metal screws and n-CDHA/PAA composite biomaterial screws. Fracture healing was monitored at 1, 4, 12, and 24 weeks, respectively, using X-ray observation, Micro-CT imaging, and SEM. Integration at the material-bone interface and the condition of neo-tissue were assessed through these imaging techniques. The Ad-BMP-9/GT coating significantly enhanced MG63 cell adhesion, proliferation, and differentiation, while increasing BMP-9 expression in vitro. In vivo studies using a rabbit femoral fracture model confirmed the biocompatibility and osteointegration potential of the multilayer Ad-BMP-9/BMSc/GT coated n-CDHA/PAA composite biomaterial screws. Compared to control groups (medical metal screws and n-CDHA/PAA composite biomaterial screws), this material demonstrated faster fracture healing, stronger osteointegration, and facilitated new bone tissue formation with increased calcium deposition at the material-bone interface. The multilayer GT-supported BMP-9 coated n-CDHA/PAA composite biomaterials have demonstrated favorable osteogenic cell interface performance, both in vitro and in vivo. This study provides a foundation for developing innovative bone repair materials, holding promise for significant advancements in clinical applications.

Determination of the internal loads experienced by proximal phalanx fracture fixations during rehabilitation exercises.

Phalangeal fractures are common, particularly in younger patients, leading to a large economic burden due to higher incident rates among patients of working age. In traumatic cases where the fracture may be unstable, plate fixation has grown in popularity due to its greater construct rigidity. However, these metal plates have increased reoperation rates due to inflammation of the surrounding soft tissue. To overcome these challenges, a novel osteosynthesis platform, AdhFix, has been developed. This method uses a light-curable polymer that can be shaped in situ around traditional metal screws to create a plate-like structure that has been shown to not induce soft tissue adhesions. However, to effectively evaluate any novel osteosynthesis device, the biomechanical environment must first be understood. In this study, the internal loads in a phalangeal plate osteosynthesis were measured under simulated rehabilitation exercises. In a human hand cadaver study, a plastic plate with known biomechanical properties was used to fix a 3mm osteotomy and each finger was fully flexed to mimic traditional rehabilitation exercises. The displacements of the bone fragments were tracked with a stereographic camera system and coupled with specimen specific finite element (FE) models to calculate the internal loads in the osteosynthesis. Following this, AdhFix patches were created and monotonically tested under similar conditions to determine survival of the novel technique. The internal bending moment in the osteosynthesis was 6.78 ± 1.62Nmm and none of the AdhFix patches failed under the monotonic rehabilitation exercises. This study demonstrates a method to calculate the internal loads on an osteosynthesis device during non-load bearing exercises and that the novel AdhFix solution did not fail under traditional rehabilitation protocols in this controlled setting. Further studies are required prior to clinical application.

Alat Feeding Ayam Otomatis Berbasis Arduino

The increasing population in Indonesia has resulted in increased food needs. One of the factors that affects chicken production is the management of the feeding system. The purpose of this study is to design and create an automatic chicken feeder based on Arduino. Calibrate the Load Cell Sensor. Control the AC motor as a metal screw driver for feeding with a load cell sensor. Determine the amount of chicken feed according to the specified setting point and Connect the MCU Node to the telegram. This study uses the "Research and development" research method. Consisting of literature studies, hardware design, software design, tool design, and data collection, analysis and conclusions. Overall testing was carried out for 2 days starting from 6 am to 4 pm. The capacity of the tank is filled with 3 kg of feed. The setting point for feeding in the morning is 200 grams while in the afternoon it is 300 grams, for feed output there are 2 containers. Testing on the first day at 7 am the weight of the feed coming out of container 1 was 221 grams while in container 2 it was 225 grams, for 4 pm the weight of the feed coming out of container 1 was 352 grams while in container 2 it was 357 grams. Testing on the second day at 7 am the weight of the feed coming out of container 1 was 219 grams while in container 2 it was 221 grams, for 4 pm the weight of the feed coming out of container 1 was 346 grams while in container 2 it was 348 grams. Telegram notification sends a message when the amount of feed remaining is 1405 grams. The results of the weight of the feed coming out are different from the specified setting point value, the amount of feed coming out exceeds the setting point value. This is because the output hole of the feed that comes out through the PVC pipe is too large. An "automatic chicken feed tool based on Arduino" has been successfully created, the tool created is equipped with a load cell sensor that facilitates the process of feeding chickens. Making a system for pouring feed into the hopper automatically by making a conveyor so that it does not need to be done manually. Making automatic chicken feed based on Arduino on a large scale so that it can cover a larger number. Addition of making automatic drinking places on automatic chicken feed based on Arduino.

On-site extraction of benzophenones from swimming pool water using hybrid tapes based on the integration of hydrophilic-lipophilic balance microparticles and an outer magnetic nanometric domain

An on-site extraction device is presented consisting of scotch tape modified with concentric domains of micrometric hydrophilic-lipophilic balance (HLB) particles surrounded by a ring of nanometric magnetic ones. On the one hand, HLB microparticles are readily available at the surface of the tape, exposed to interact with the target analytes, being responsible for the extraction capacity of the sorptive phase. On the other hand, the presence of magnetic nanoparticles enables the attachment of the modified tape onto a metallic screw via a magnet, which is then coupled to a wireless drill, enabling the stirring of the microextraction device. Both are simply fixed to the cost-effective, flexible, and versatile support, i.e., scotch tape, owing to their adhesive properties. The microextraction device has been applied to the determination of six benzophenones in swimming pool water samples. The variables that may affect the extraction process have been evaluated. Under the optimum conditions and using liquid chromatography-tandem mass spectrometry as the instrumental technique, the method provided a limit of detection of 0.03 µg L−1. The intra-day precision, evaluated at three different concentration levels and expressed as relative standard deviation, was lower than 10%, which also comprises the variability within single-use sorptive tapes. The accuracy, calculated with spiked samples and expressed as relative recovery, ranged from 71 to 138%. The method was applied to the analysis of swimming pool water, revealing the presence of such compounds.Graphical

Enhanced Degradability of Thiol-Ene Composites through the Inclusion of Isosorbide-Based Polycarbonates.

Open reduction internal fixation metal plates and screws remain the established standard-of-care for complex fracture fixation. They, however, have drawbacks such as limited customization, soft-tissue adhesions, and a lack of degradation. Bone cements and composites are being developed as alternative fixation techniques in order to overcome these issues. One such composite is a strong, stiff, and shapeable hydroxyapatite-containing material consisting of 1,3,5-triazine-2,4,6-trione (TATO) monomers, which cures through high energy visible light-induced thiol-ene coupling (TEC) chemistry. Previous human cadaver and in vivo studies have shown that patches of this composite provide sufficient fixation for healing bone fractures; however, the composite lacks degradability. To promote degradation through hydrolysis, new allyl-functionalized isosorbide-based polycarbonates have been added into the composite formulation, and their impact has been evaluated. Three polycarbonates with allyl functionalities, located at the termini (aPC1 and aPC2) or in the backbone (aPC3), were synthesized. Composites containing 1, 3, and 5 wt % of aPCs 1-3 were formulated and evaluated with regard to mechanical properties, water absorption, hydrolytic degradation, and cytotoxicity. Allyl-functionalized polycaprolactone (aPCL) was synthesized and used as a comparison. When integrated into the composite, aPC3 significantly impacted the material's properties, with the 5 wt % aPC3 formulation showing a significant increase in degradation of 469%, relative to the formulation not containing any aPCs after 8 weeks' immersion in PBS, along with a modest decrease in modulus of 28% to 4.01 (0.3) GPa. Osteosyntheses combining the aPC3 3 and 5 wt % formulations with screws on synthetic bones with ostectomies matched or outperformed the ones made with the previously studied neat composite with regard to bending stiffness and strength in four-point monotonic bending before and after immersion in PBS. The favorable mechanical properties, increased degradation, and nontoxic characteristics of the materials present aPC3 as a promising additive for the TATO composite formulations. This combination resulted in stiff composites with long-term degradation that are suitable for bone fracture repair.

Advantages of using template guides in children for the correction of congenital spinal deformities and thoracic anomalies

BACKGROUND: In children, progressive congenital deformities of the thoracic spine combined with thoracic anomalies require surgical intervention to correct the curvature and prevent further progression during the child’s growth. Surgical correction of congenital deformity caused by segmentation disorders of the lateral surfaces of the vertebral bodies with unilateral rib synostosis aims at full correction of the existing curvature using the transpedicular spinal system and is an effective and reliable treatment option for these patients. However, this technology requires precise and correct installation of the supporting elements of the metal structure to exclude possible irreversible complications. A solution is the use of template guides in the installation of the support elements of the spinal metal structure. AIM: This study aimed to conduct a comparative analysis of the results of using template guides for the placement of transpedicular screws with the free-hand method in children during surgical correction of congenital spinal deformities combined with thoracic anomalies. MATERIALS AND METHODS: The results of surgical treatment of 20 patients, aged 3–9 years, were analyzed retrospectively to compare the time and accuracy of spinal metal support element placement with and without the use of template guides. The data collected included demographic information, time of bone canal formation, accuracy of spinal transpedicular screw placement, and various complications. RESULTS: Compared with the free-hand method, the use of template guides in the surgical correction of congenital spinal deformities combined with thoracic anomalies in children reduces the time of bone canal formation and increases the accuracy of metal screw placement. These results confirm the efficacy and safety of using template guides during spinal surgery in children with these congenital malformations. CONCLUSIONS: The use of template guides is an effective and reliable method of inserting transpedicular metal screws in the correction of congenital spinal deformities combined with thoracic anomalies in children, which increases the accuracy of implantation of support elements and reduces the surgical time. These results confirm the necessity of using template guides in the correction of congenital spinal deformities in children.

Clinical and radiological outcome following arthroscopic Latarjet with cerclage FiberTape fixation with a minimum 1-year follow-up

The rates of implant-related complications are significant following the Latarjet procedure using metal screws in patients with recurrent shoulder dislocation and bone loss. The purpose of this study is to evaluate the short-term outcome following the arthroscopic Latarjet procedure using cerclage FiberTape (Arthrex, Naples, FL, USA) combined with remplissage and capsulolabral repair. It was hypothesized that performing the procedure with cerclage FiberTape would provide sturdy fixation, comparable to the conventional method of using metal screws, while averting hardware-related complications attributed to the latter in published literature. A prospective study was performed in a single institution between 2020 and 2022, with all surgeries performed by a single fellowship-trained shoulder surgeon who has ample experience in performing arthroscopic screw Latarjet procedures. Patient demographics, number of dislocations before surgery, arm dominance, ligamentous laxity, type of sporting activity, Instability Severity Index Score, and percentage of bone loss on the glenoid and humeral sides were recorded. The patients were followed up with visual analog scale, American Shoulder and Elbow Surgeons score, Rowe score, and Walch-Duplay score preoperatively and postoperatively. The coracoid graft position, healing, and remodeling were assessed with computed tomography scans at 3 months postoperatively. Minimum clinical follow-up was for a period of one year. Overall, 10 patients (all males, average age 28±8.8 years) were operated on with an arthroscopic Latarjet procedure using cerclage FiberTape. The minimum follow-up period was 12 months, and the mean follow-up was 13.2 months. The median and individual visual analog scores during arm motion, American Shoulder and Elbow Surgeons scores, Rowe scores, and Walch-Duplay scores improved in the follow-up period. Computed tomography scans at 3 months showed flushed graft position in 5 patients, medial graft position in two patients, and three patients showed graft nonunion with migration. Out of 10 patients, seven had good graft union in follow-up scans. None of the patients required revision surgery. All three patients with graft nonunion were kept under follow-up beyond the study period for recurrence of instability. Our study demonstrated that arthroscopic Latarjet using cerclage FiberTape fixation combined with remplissage and capsulolabral repair resulted in high rate of graft loosening and migration (30%). Nonetheless, patients in whom the coracoid graft had united, as well as those in whom it had not, all had good to excellent functional and clinical outcomes, no complications, and did not require any revision surgery.

In Vivo Biocompatibility Study on Functional Nanostructures Containing Bioactive Glass and Plant Extracts for Implantology.

In this paper, the in vivo behavior of orthopedic implants covered with thin films obtained by matrix-assisted pulsed laser evaporation and containing bioactive glass, a polymer, and natural plant extract was evaluated. In vivo testing was performed by carrying out a study on guinea pigs who had coated metallic screws inserted in them and also controls, following the regulations of European laws regarding the use of animals in scientific studies. After 26 weeks from implantation, the guinea pigs were subjected to X-ray analyses to observe the evolution of osteointegration over time; the guinea pigs' blood was collected for the detection of enzymatic activity and to measure values for urea, creatinine, blood glucose, alkaline phosphatase, pancreatic amylase, total protein, and glutamate pyruvate transaminase to see the extent to which the body was affected by the introduction of the implant. Moreover, a histopathological assessment of the following vital organs was carried out: heart, brain, liver, and spleen. We also assessed implanted bone with adjacent tissue. Our studies did not find significant variations in biochemical and histological results compared to the control group or significant adverse effects caused by the implant coating in terms of tissue compatibility, inflammatory reactions, and systemic effects.

Comparison of Graft Type and Fixation Method in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis Based on Randomized Control Studies.

The anterior cruciate ligament (ACL) is the most commonly injured ligament in the knee. ACL reconstruction (ACLR) proves the standard for treating this injury. However, graft choice and method of fixation remain a heavily debated topic. This study investigates the following: bone-patellar tendon-bone (BPTB) vs. hamstring tendon (HT) autograft, single-bundle vs. double-bundle hamstring graft, and metal vs. bioabsorbable screws in ACLR. A systematic review was performed on PubMed and Google Scholar according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data were collected on patient demographics, complications, and functionality scores including International Knee Documentation Committee (IKDC) and Lysholm scores. A systematic review and meta-analysis were conducted with Review Manager. Outcome measurements were determined using forest plots with significant differences considered p < 0.05. Twenty-five studies were included, accounting for 2,170 patients. No statistically significant difference was appreciated when comparing BPTB to hamstring autografts. Patients who received a double bundle HT autograft exhibited significantly superior outcomes in terms of revision (p = 0.05), failure (p = 0.002), normal pivot shift tests (p = 0.04), and normal IKDC (p = 0.008). When comparing screw types, bioabsorbable screws had a greater Lysholm score (p = 0.01) and lower failure rates for copolymer screws (p = 0.03). Overall, the data collected suggested that BPTB and HT autografts display similar postoperative results. However, if an HT autograft is used, the data suggest a double-bundle graft improves both functionality and decreases the possible complications. Finally, bioabsorbable screws prove superior to metal screws when looking at both functionality and failure rates. Further research into the superior graft type is still needed. Level II. See Instructions for Authors for a complete description of levels of evidence.

40-Year Outcome of Old-School, Non-Surgical Endodontic Treatment: Practice-Based Retrospective Evaluation.

(1) Background: Non-surgical endodontic treatment has been shown to be clinically successful; however, clinical long-term data are scarce. This practice-based retrospective clinical investigation evaluated endodontic outcomes over 40 years and identified relevant clinical co-factors. (2) Methods: Two experienced dental practitioners in two different private dental practices treated 174 patients with 245 teeth from 1969 to 1993. After root canal obturation, either a new direct restoration (amalgam, resin composite, or glass-ionomer cement) or the re-cementation of a pre-existing prosthetic restoration or renewal of prosthetic restoration followed. Metal posts (operator A) or metal screws (operator B) were inserted when coronal substance loss was significant. The primary outcome (i.e., tooth survival) was achieved when the endodontically treated tooth was, in situ, painless and had full function at the end of the observation period. A secondary outcome, the impact of different prognostic factors on survival rate, was evaluated. (3) Results: The overall mean survival was 56.1% of all treated teeth after 40 years of clinical service, resulting in an annual failure rate of 1.1%. Most investigated clinical co-factors (jaw, tooth position, intracanal dressings, post/screw placement, and gender) showed no significant influence on survival. (4) Conclusions: Even with materials and techniques from the 1970s and 1980s, successful root canal treatment was achievable. Except for post-endodontic restorations, most of the evaluated factors had no significant influence on the clinical long-term survival of root canal-treated teeth.

Development of a constructive solution of wood columns and crossbars interfaces on metal overlays and screws

Development of a constructive solution of wood columns and crossbars interfaces on metal overlays and screws

Novel illuminoss photodynamic bone stabilization system: normal and post-operative complication imaging findings in the emergency setting.

The mainstay orthopedic surgical technique for fracture fixation involves metal plates, screws, and rods. While these methods are effective, they exhibit high rates of complications within specific populations, particularly among patients with pathologic and insufficiency fractures. IlluminOss represents a novel photodynamic bone stabilization system, approved for use in multiple countries, that serves as an alternative to traditional fracture fixation approaches for patients experiencing pathologic, traumatic, and fragility fractures. Despite the initial success of the system in fostering fracture healing, no study has comprehensively examined the radiological attributes of the IlluminOss Stabilization system thus far. The emergency radiologist is often the first point of imaging identification and interpretation for patients presenting with suspected postoperative complications, requiring evolving knowledge of both expected and atypical appearances for novel surgical implants. This manuscript's objective is to delve into the design and clinical application of IlluminOss, scrutinize relevant normal imaging findings across various modalities, and delineate potential complications associated with the IlluminOss Stabilization system for traumatic, pathologic, and fragility fractures that are increasingly encountered in the emergency department setting.

Systemically administered zoledronic acid activates locally implanted synthetic hydroxyapatite particles enhancing peri-implant bone formation: A regenerative medicine approach to improve fracture fixation

Fracture fixation in an ageing population is challenging and fixation failure increases mortality and societal costs. We report a novel fracture fixation treatment by applying a hydroxyapatite (HA) based biomaterial at the bone-implant interface and biologically activating the biomaterial by systemic administration of a bisphosphonate (zoledronic acid, ZA). We first used an animal model of implant integration and applied a calcium sulphate (CaS)/HA biomaterial around a metallic screw in the tibia of osteoporotic rats. Using systemic ZA administration at 2-weeks post-surgery, we demonstrated that the implant surrounded by HA particles showed significantly higher peri‑implant bone formation compared to the unaugmented implants at 6-weeks. We then evaluated the optimal timing (day 1, 3, 7 and 14) of ZA administration to achieve a robust effect on peri‑implant bone formation. Using fluorescent ZA, we demonstrated that the uptake of ZA in the CaS/HA material was the highest at 3- and 7-days post-implantation and the uptake kinetics had a profound effect on the eventual peri‑implant bone formation. We furthered our concept in a feasibility study on trochanteric fracture patients randomized to either CaS/HA augmentation or no augmentation followed by systemic ZA treatment. Radiographically, the CaS/HA group showed signs of increased peri‑implant bone formation compared with the controls. Finally, apart from HA, we demonstrated that the concept of biologically activating a ceramic material by ZA could also be applied to β-tricalcium phosphate. This novel approach for fracture treatment that enhances immediate and long-term fracture fixation in osteoporotic bone could potentially reduce reoperations, morbidity and mortality. Statement of significance• Fracture fixation in an ageing population is challenging. Biomaterial-based augmentation of fracture fixation devices has been attempted but lack of satisfactory biological response limits their widespread use. • We report the biological activation of locally implanted microparticulate hydroxyapatite (HA) particles placed around an implant by systemic administration of the bisphosphonate zoledronic acid (ZA). The biological activation of HA by ZA enhances peri‑implant bone formation. •Timing of ZA administration after HA implantation is critical for optimal ZA uptake and consequently determines the extent of peri‑implant bone formation. • We translate the developed concept from small animal models of implant integration to a proof-of-concept clinical study on osteoporotic trochanteric fracture patients. • ZA based biological activation can also be applied to other calcium phosphate biomaterials.

Palpation and fluoroscopy are valid but unreliable for the assessment of femoral tunnel position after medial patellofemoral ligament reconstruction

ObjectivesThe purpose of this study was to evaluate the validity and reliability of two techniques, palpation and fluoroscopy, for assessing medial patellofemoral ligament (MPFL) reconstruction femoral tunnel position accuracy. MethodsTwenty-one fresh frozen cadaveric knees had an MPFL femoral tunnel drilled and filled with a metal screw. Tunnels were created in a nonstandard fashion to ensure the sample included a range of tunnel positions from poor to ideal. Six experienced sport medicine and arthroscopy surgeons evaluated the placement of the femoral tunnel by palpating the screw in relation to anatomic landmarks and by fluoroscopy related to Schöttle's Point. They evaluated 1) the accuracy of femoral tunnel placement, 2) the direction of tunnel error, and 3) the clinical acceptability of the tunnel position. Validity measures included sensitivity, specificity, and correlation to clinical acceptability, which were calculated for the palpation and fluoroscopic assessments. Reliability measures included interrater reliability (ICC 2,k) for femoral tunnel accuracy and percent agreement of the raters' tunnel direction assessment. ResultsThe palpation method demonstrated a sensitivity of 0.79 and specificity of 0.84 for assessing the accuracy of femoral tunnel placement, while the fluoroscopic method showed a sensitivity of 0.83 and specificity of 0.92. Pearson correlation coefficients for clinical acceptability of tunnel position were high, with both techniques ranging from .589 to .854. Interrater reliability for the palpation and fluoroscopic techniques for assessment of tunnel accuracy were 0.31 and 0.55 (ICC 2,k), respectively. Assessment of the direction of tunnel error was good with the fluoroscopic technique slightly more accurate than palpation. ConclusionThis study demonstrated that both palpation and fluoroscopy are valid techniques for assessing femoral tunnel position after MPFL reconstruction. Despite demonstrating good validity, the accuracy of assessing tunnel position was unreliable in a group of six experienced knee surgeons. Further research into MPFL reconstruction femoral tunnel assessment techniques, including patient-specific reference standards, is warranted. Level of EvidenceLevel 2.

Research on Metal and Living Foreign Object Detection Method for Electric Vehicle Wireless Charging System

In the electric vehicle wireless power transmission system, the high-frequency alternating magnetic field between the transmitter and receiver can have a certain impact on the health of living organisms and may even lead to lesions. In addition, metal foreign objects in an alternating magnetic field can cause their own heating or even cause fires due to the eddy current effect, so foreign object detection is an essential function in the wireless power transmission system of electric vehicles. In order to prevent metals and living organisms from entering the charging area and causing harm to the charging system and living organisms, this paper proposes a method for detecting living organisms and metal foreign objects. Firstly, the equivalent circuits for the detection systems of the living organism foreign objects and metal foreign objects are established, respectively, and the working theory of the detection system is analyzed by deriving equations. Secondly, the comb capacitor simulation model was constructed, and the comb capacitor electrode spacing, wire thickness, and capacitor spacing were designed based on the scale factor γ to explore the effects of the height and bottom area of the living organism’s foreign object on the comb capacitor. We constructed a simulation model of the detection coil and designed the inner diameter D, the number of turns N, and the wire spacing S of the detection coil according to the scale factor β. An arrayed detection coil and comb capacitor combination mode is proposed to realize the function of the simultaneous detection of metal and living organism foreign objects, and a compensation capacitor is introduced to keep the detection system in a resonant state. Lastly, a platform for foreign object detection experiments was set up to detect metal screws and beef chunks compared to the detection area without foreign objects. Metal screws entering the detection area cause a 20% voltage drop in the detection circuit resistor, and beef chunks entering the detection area cause a 30% voltage drop in the detection circuit resistor, so the detection method is effective in detecting both metals and living organisms. The feasibility of the combined mode of arrayed detection coils and comb capacitors was verified.