Bone Fixation Research Articles

Low energy gunshot injuries: Does removal of retained bullet fragmentation at the time of internal fixation reduce the risk of fracture related infection?

ObjectiveTo examine the effects of RBF (Retained Bullet Fragment) removal at the time of long bone fixation on FRI (fracture related infection) rates in low energy GSI (Gunshot Injury) related fractures. DesignRetrospective Cohort Study SettingLevel 1 Academic Trauma Center InterventionRetrospective review of the impact of RBFs on the risk of FRI when employing internal fixation in low energy GSI (Gunshot Injury) related fractures. In situations where the injury pattern requires surgical fixation, the question arises as to whether or not the RBFs need to be removed to prevent FRI. Main outcome measuresWhether or not the RBFs removed in our patient population prevented short- and long-term fracture related infection after low-energy gunshot injury (FRI-LGI). ResultsOf the 2,136 GSI related fractures, 131 patients met inclusion criteria, 81 patients underwent removal (R) of RBFs at the time of internal fixation while 50 patients did not undergo any removal (NR) at time of internal fixation. Among the patients who underwent surgical intervention, (Open Reduction Internal Fixation) ORIF was performed in 55 cases (R: 39; NR: 16), and (Intramedullary Nail) IMN was performed in 76 cases (R: 42; NR: 34). The overall rate of deep FRI-LGI was 6.9 % of the 131-patient cohort. We found that removal of RBFs had a statistically significant impact on the rate of deep FRI-LGI when compared to the NR group (p = 0.031). In the RBF removal group, only two patients (2.4 %) developed deep FRI-LGIs, whereas in the NR group, seven patients (14.0 %) developed deep FRI-LGIs. The incidence of early FRI-LGI was higher in the NR group (median 0.6 months) compared to the R group, which was associated with late FRI-LGIs (median 10.1 months) when they occurred. DiscussionIn our study population, we found a statistically significantly increased incidence of deep and early FRI-LGI when RBFs are not removed at the time of extra-articular long bone internal fixation. The presence of retained bullet fragments following internal fixation may pose a risk factor for future development of deep FRI-LGI. We believe a surgeon should use their best judgment as to whether a RBF can safely be removed at the time of long bone fixation. Based on our findings, if safely permitted, RBF removal should be considered at the time of GSI long bone fixation resulting from low energy hand gun injuries.

Tragacanth gum-based hydrogels for drug delivery and tissue engineering applications

Natural polymers have many uses, and Tragacanth gum is just one of them. Many people are interested in natural gums because of their many attractive characteristics, such as being ‘green’ bio-based renewable materials, being easily accessible, inexpensive, and structurally diverse. One class of naturally occurring polysaccharides is called gum because of its tendency to create a gel or a thick solution. Among the many plant-based raw materials, these polysaccharide gums are abundant. Hydrogels, which are three-dimensional polymeric webs that can imitate live tissues, have demonstrated remarkable potential as adjustable biomaterials in numerous regenerative techniques due to their high water or biological exudate absorption capacities. Natural polysaccharides, often known as gums, are present in many different types of trees and possess many desirable properties, such as being renewable, biocompatible, biodegradable, non-toxic, and amenable to chemical modification. Many people are curious about certain parts of the food, water, energy, biotech, environmental, and healthcare sectors as of now. Gum, a type of very important and unique food ingredient, has many vital uses in the food business. Cosmetics, coating, photosensitive resin, fertilizer, casting, pharmaceuticals, and tobacco are just a few of the non-food businesses that make use of their strong water-affinity and structural plasticity. There are a lot of benefits to hydrogels made from natural gums as opposed to those made from synthetic sources. Synthesis hydrogel polymers have been the center of interest among these non-food applications because of their extensive use in the pharmaceutical and medical fields. The Tragacanth gum hydrogels used for medication delivery and tissue engineering have been the focus of this study. We also paid close attention to drug delivery, physical-chemical properties, and the extraction of Tragacanth gum. Our research has a wide range of biomedical applications, including tissue engineering for bone, skin, fixation of bone, periodontal, and cartilage. Possible futures based on hydrogels made of Tragacanth gum were likewise our primary focus.

Biportal endoscopic bone graft repair and percutaneous screw fixation for lumbar spondylolysis-technical note and clinical outcomes.

Lumbar spondylolysis involves a bony defect in the vertebral pars interarticularis, predominantly affecting the lower lumbar spine. This condition is a significant etiological factor in lumbar instability and recurrent lower back pain, particularly in young individuals. While conservative treatments are the primary intervention, they often fail to provide relief, necessitating surgical approaches. Notwithstanding, executing bone grafting and fixation in the pars interarticularis defect simultaneously through minimally invasive surgery remains challenging. This study elucidates the biportal endoscopic spinal surgery (BESS) technique, innovatively applied for bone graft repair and percutaneous cannulated screw fixation in a patient with lumbar spondylolysis. We offer a detailed walkthrough of the technical procedures supplemented with follow-up radiographic evidence. The BESS technique facilitated meticulous clearance of the defect site, coupled with bone grafting and cannulated screw fixation, effectively addressing lumbar spondylolysis through a minimally invasive approach. This method holds promise for achieving substantial osseous fusion at the vertebral pars interarticularis defect site. The BESS procedure for lumbar spondylolysis ensures a clean and prepared defect site for grafting and encourages successful osseous fusion, spotlighting its potential as a viable surgical strategy in managing this condition.

Feline radial and ulnar diaphyseal fractures: a retrospective study of 49 cases comparing single bone fixation and dual bone fixation.

The objectives of this study were to report the complications in radial and ulnar diaphyseal fractures in cats and to compare the differences in outcome between single and dual bone internal fixation. Medical records between 2004 and 2022 were searched retrospectively for cats with antebrachial diaphyseal fractures treated with internal bone-plate fixation. In total, 49 cases were included from six referral hospitals, including one teaching hospital. Patient information was collated, including fracture configuration, location, repair method and clinical outcome as assessed by veterinary physical examination, radiography and owner questionnaire. A total of 47 cats (mean age 4.2 years) were included. Fractures were located distally (24/49, 49%), proximally (13/49, 26.5%) and mid-diaphyseally (12/49, 24.5%). Dual bone fixation was used in 13/49 (26.5%) cases, with only 1/13 (7.7%) having major complications. By comparison, 4/36 (11.1%) of single plated fractures had major complications. Single bone fixation was 14.25 times more likely (95% confidence interval [CI] 2.07-97.99) to have a successful outcome (veterinarian-assigned score of 0) compared with dual bone fixation (P = 0.007). When evaluating owner-assessed outcomes, single bone fixation was 9.4 times more likely (95% CI 1.4-61.96) to have a successful outcome (owner score of 0) compared with dual bone fixation (P = 0.019). Fractures that were repaired with single bone fixation had a greater chance of a better outcome. Although the difference was not significant, there was a higher major complication rate and a lower minor complication rate for cases treated with single bone fixation compared with dual bone fixation. The majority of fractures were located in the distal diaphysis. Comminution of the fracture and concurrent orthopaedic issues did not significantly affect the outcome. Further prospective studies with standardised follow-up, radiographic assessment, surgeon and implants are required to truly assess the difference between dual and single bone fixation.

Enhanced Mechanical Properties, Corrosion Resistance, Cytocompatibility, Osteogenesis, and Antibacterial Performance of Biodegradable Mg-2Zn-0.5Ca-0.5Sr/Zr Alloys for Bone-Implant Application.

Magnesium (Mg) alloys are widely used in bone fixation and bone repair as biodegradable bone-implant materials. However, their clinical application is limited due to their fast corrosion rate and poor mechanical stability. Here, the development of Mg-2Zn-0.5Ca-0.5Sr (MZCS) and Mg-2Zn-0.5Ca-0.5Zr (MZCZ) alloys with improved mechanical properties, corrosion resistance, cytocompatibility, osteogenesis performance, and antibacterial capability is reported. The hot-extruded (HE) MZCZ sample exhibits the highest ultimate tensile strength of 255.8 ± 2.4MPa and the highest yield strength of 208.4 ± 2.8MPa and an elongation of 15.7 ± 0.5%. The HE MZCS sample shows the highest corrosion resistance, with the lowest corrosion current density of 0.2 ± 0.1µA cm-2 and the lowest corrosion rate of 4 ± 2µm per year obtained from electrochemical testing, and a degradation rate of 368µm per year and hydrogen evolution rate of 0.83 ± 0.03mL cm-2 per day obtained from immersion testing. The MZCZ sample shows the highest cell viability in relation to MC3T3-E1 cells among all alloy extracts, indicating good cytocompatibility except at 25% concentration. Furthermore, the MZCZ alloy shows good antibacterial capability against Staphylococcus aureus.

Influence of silver nanoparticles addition on antibacterial properties of PEO coatings formed on magnesium

Magnesium is a biodegradable material and thus could be a choice for bone fixation devices and implants with a specific purpose. This study aims to enhance the anti-corrosive, biocompatible, and antibacterial properties on magnesium-based materials through ceramic coatings formation. To achieve this the silicate-based electrolyte was used to create of Plasma Electrolytic Oxidation (PEO) coatings. During investigation the bioactive surfaces were presented by highly developed morphology with pore size from 0.008 ± 0.01 to 0.098 ± 0.14 μm2. The thickness of the coatings reached 7 μm, which provides better corrosive behaviour. The silver nanoparticles (AgNPs) added during plasma electrolytic oxidation (PEO) into a silicate electrolytic bath allowed for achieving enhanced bioactive properties of coating. It increased hydrophilicity from 118° to 62° and showed no cytotoxic effects, which made the coatings promising for further biomedical investigations. Moreover, incorporation of AgNPs into the PEO coating led to release of silver during immersion test, which enhanced antibacterial properties of the surfaces.

Pull-out strength of screws in long bones at different insertion angles: finite element analysis and experimental investigations

Abstract Different types of plates are available to allow insertion of screws for internal fixation of long bone fractures. The aim of the study was to determine the effect of the insertion of screws at different angles on a long bone to the pull-out strength. Using 3D printed bone models, we tested the pull-out strength of screws in long bones at insertion angles between 0 and 40° with both finite element analysis and on printed models experimentally and compared the results. Test samples and cortical screws used were modeled with SolidWorks software and analyzed with Ansys software. As the screw insertion angle increases, the pull-out forces on the test specimens increase from 61.14 ± 3.5 N at 0° to 273 ± 6.8 N at 40° with an exception of a small drop between 15 and 20° from 235.4 ± 6.2 to 233 ± 6.9 N. Both methods showed an increase in the pull-out strength of screws as the insertion angle increases. This might be applicable in the clinical practice of bone fixation. Further studies on plate and screw fixation are needed to complement the findings.

Accuracy of the GeneXpert® MRSA/SA SSTI test to diagnose methicillin-resistant Staphylococcus spp. infection in bone fixation and fusion and management of infected non-unions

IntroductionThe GeneXpert® MRSA/SA SSTI (Methicillin Resistant Staphylococcus aureus/S. aureus skin and soft tissue infection) PCR test allows early detection of methicillin resistance in staphylococci. This test was developed for skin infections and has been evaluated for prosthetic joint infections but, to our knowledge, has not been evaluated for hardware infections outside of arthroplasties. Furthermore, we conducted a retrospective study in patients with non-prosthetic osteosynthesis hardware aiming: (1) to identify the diagnostic values of the PCR test compared to conventional cultures and the resulting rate of appropriate antibiotic therapy; (2) to identify the rate of false negative (FN) results; (3) to identify and compare the rates of failure of infectious treatment (FN versus others); (4) to search for risk factors for FN of the PCR test. HypothesisThe PCR test allowed early and appropriate targeting of antibiotic therapy. Material and methodsThe results of PCR tests and conventional cultures for osteoarticular infections of non-prosthetic hardware over four years (2012–2016) were compared to identify the diagnostic values of using the results of conventional culture as a reference and the rate of appropriate antibiotic therapies. Infectious management failures between the results of the FN group and the others were compared, and variables associated with a FN of the PCR test were identified. ResultsThe analysis of 419 PCR tests allowed us to establish a sensitivity of 42.86%, a specificity of 96.82%, a positive predictive value of 60% and a negative predictive value of 93.83%. Using the results of the PCR test for the targeting of postoperative antibiotic therapy, it was suitable for staphylococcal coverage in 90.94% (381/419). The rates of patients for whom infectious treatment failed were not significantly different between the FN group and the other patients (20.8% versus 17.7%, respectively; Hazard Ratio=1.12 (95%CI 0.47-2.69, p=0.79)). A skin opening during the initial trauma (p=0.005) and a polymicrobial infection were significantly associated with a risk of FN from the PCR test (p<0.001). ConclusionThe PCR test makes it possible to reduce the duration of empirical broad-spectrum antibiotic therapy during the treatment of an infection of osteosynthesis hardware but causes a lack of antibiotic coverage in 9.06% of cases. Level of evidenceIII; diagnostic case control study.

Computational models of bone fracture healing and applications: a review.

Fracture healing is a very complex physiological process involving multiple events at different temporal and spatial scales, such as cell migration and tissue differentiation, in which mechanical stimuli and biochemical factors assume key roles. With the continuous improvement of computer technology in recent years, computer models have provided excellent solutions for studying the complex process of bone healing. These models not only provide profound insights into the mechanisms of fracture healing, but also have important implications for clinical treatment strategies. In this review, we first provide an overview of research in the field of computational models of fracture healing based on CiteSpace software, followed by a summary of recent advances, and a discussion of the limitations of these models and future directions for improvement. Finally, we provide a systematic summary of the application of computational models of fracture healing in three areas: bone tissue engineering, fixator optimization and clinical treatment strategies. The application of computational models of bone healing in clinical treatment is immature, but an inevitable trend, and as these models become more refined, their role in guiding clinical treatment will become more prominent.

Exploring Advanced Functionalities of Carbon Fiber-Graded PEEK Composites as Bone Fixation Plates Using Finite Element Analysis.

This study aims to address the challenges associated with conventional metallic bone fixation plates in biomechanical applications, such as stainless steel and titanium alloys, including stress shielding, allergic reactions, corrosion resistance, and interference with medical imaging. The use of materials with a low elastic modulus is regarded as an effective approach to overcome these problems. In this study, the impact of different types of chopped carbon fiber-reinforced polyether ether ketone (CCF/PEEK) functionally graded material (FGM) bone plates on stress shielding under static and instantaneous dynamic loading was explored using finite element analysis (FEA). The FGM bone plate models were established using ABAQUS and the user's subroutine USDFLD and VUSDFLD, and each model was established with an equivalent overall elastic modulus and distinctive distributions. The results revealed that all FGM bone plates exhibited lower stress shielding effects compared to metal bone plates. Particularly, the FGM plate with an elastic modulus gradually increased from the centre to both sides and provided maximum stress stimulation and the most uniform stress distribution within the fractured area. These findings offer crucial insights for designing implantable medical devices that possess enhanced mechanical adaptability.

IS TOTAL HIP ARTHROPLASTY FIXATION ASSOCIATED WITH OSTEOBLAST ACTIVITY IN PATIENTS WITH OSTEONECROSIS OF THE FEMORAL HEAD? A PROSPECTIVE CASE-CONTROL STUDY

Total hip arthroplasty (THA) outcome in patients with osteonecrosis of the femoral head ONFH) are excellent, however, there is controversy when compared with those in patients with osteoarthritis (OA). Reduced mineralization capacity of osteoblasts of the proximal femur in patients with ONFH could affect implant fixation.We asked if THA fixation in patients with ONFH is worse than in those with OA.We carried out a prospective comparative case (OA)-control (ONFH) study of patients undergoing THA at our hospital between 2017 and 2019. The minimum follow-up was 2 years. Inclusion criteria were patients with uncemented THA, younger than 70 years old, a Dorr femoral type C and idiopathic ONFH. We compared the clinical (Merlé D'Aubigné-Postel score) and radiological results related with implant positioning and fixation. Engh criteria and subsidence were assessed at the immediate postoperative, 12 weeks, 6 months, 12 months and yearly. Osteoblastic activity was determined by mineralization assay on primary cultures of osteoblasts isolated from trabecular bone samples collected from the intertrochanteric area obtained during surgery.Group 1 (ONFH) included 18 patients and group 2 (OA), 22. Average age was 55.9 years old in group 1 and 61.3 in group 2. (p=0.08). There were no differences related with sex, Dorr femoral type or femoral filling. The mean clinical outcome score was 17.1 in group 1 and 16.5 in group 2 (p=0.03). There were no cases of dislocation, infection, or revision surgery in this series. There were 5 cases (28%) of femoral stem subsidence greater than 3mm within 6 first months in group 1 and 1 case (4.5%) in group 2 (p=0.05).Although there were no significant differences related to clinical results, bone fixation was slower, and a greater subsidence was observed in patients with ONFH. Greater femoral stem subsidence was associated with a lower capacity for mineral nodule formation in cultured osteoblasts. The surgical technique could influence THA outcome in patients with reduced mineralization capacity of osteoblasts.

Restoring implant fixation strength in osteoporotic bone with a hydrogel locally delivering zoledronic acid and bone morphogenetic protein 2. A longitudinal in vivo microCT study in rats

Osteoporosis poses a major public health challenge, and it is characterized by low bone mass, deterioration of the microarchitecture of bone tissue, causing a consequent increase in bone fragility and susceptibility to fractures and complicating bone fixation, particularly screw implantation. In the present study, our aim was to improve implant stability in osteoporotic bone using a thermoresponsive hyaluronan hydrogel (HA-pNIPAM) to locally deliver the bisphosphonate zoledronic acid (ZOL) to prevent bone resorption and bone morphogenetic protein 2 (BMP2) to induce bone formation.Adult female Wistar rats (n = 36) were divided into 2 treatment groups: one group of SHAM-operated animals and another group that received an ovariectomy (OVX) to induce an osteoporotic state. All animals received a polyetheretherketone (PEEK) screw in the proximal tibia. In addition, subgroups of SHAM or OVX animals received either the HA-pNIPAM hydrogel without or with ZOL/BMP2, placed into the defect site prior to screw implantation. Periprosthetic bone and implant fixation were monitored using longitudinal in vivo microCT scanning post-operatively and at 3, 6, 9, 14, 20 and 28 days. Histological assessment was performed post-mortem.Our data showed that pure hydrogel has no impact of implant fixation The ZOL/BMP2-hydrogel significantly increased bone-implant contact and peri-implant bone fraction, primarily through reduced resorption. Statement of clinical significanceLocal delivery of ZOL and BMP2 using a biocompatible hydrogel improved implant stability in osteoporotic bone. This approach could constitute a potent alternative to systemic drug administration and may be useful in avoiding implant loosening in clinical settings.

Management of Infected Segmental Bone Defects with Antibiotic-Cement-Coated Nails in the First Stage of the Masquelet Technique. Implantation and Removal of the Cement Spacer around the Nail: A Technical Note.

Infected segmental bone defects (ISBD) of the femur and tibia pose a significant challenge. Traditionally, bone fixation in the first stage of the Masquelet technique involves external fixation, but intramedullary nail fixation has recently gained popularity. Despite this, little attention has been focused on the elaboration, implantation, and removal of the spacer around the nail. In this technical note, we present gentamicin cement-coated rigid nails as definitive fixation in the first stage. We also detail the technique for placing and removing the one-piece dyed antibiotic spacer around the nail. We highlight its potential benefits in one of the critical steps of this versatile technique.

Nasal dorsum reinforcement via bone fixation by suspension suture in structural rhinoplasty

Nasal dorsum reinforcement via bone fixation by suspension suture in structural rhinoplasty

Polyacrylic acid-reinforced organic-inorganic composite bone adhesives with enhanced mechanical properties and controlled degradability.

Bone adhesives, as alternatives to traditional bone fracture treatment methods, have great benefits in achieving effective fixation and healing of fractured bones. However, current available bone adhesives have limitations in terms of weak mechanical properties, low adhesion strength, and inappropriate degradability, hindering their clinical applications. The development of bone adhesives with strong mechanical properties, adhesion strength, and appropriate degradability remains a great challenge. In this study, polyacrylic acid was incorporated with tetracalcium phosphate and O-phospho-L-serine to form a new bone adhesive via coordination and ionic interactions to achieve exceptional mechanical properties, adhesion strength, and degradability. The bone adhesive could achieve an initial adhesion strength of approximately 3.26 MPa and 0.86 MPa on titanium alloys and bones after 15 min of curing, respectively, and it increased to 5.59 MPa and 2.73 MPa, after 24 h of incubation in water or simulated body fluid (SBF). The compressive strength of the adhesive increased from 10.06 MPa to 72.64 MPa over two weeks, which provided sufficient support for the fractured bone. Importantly, the adhesive started to degrade after 6 to 8 weeks of incubation in SBF, which is beneficial to cell ingrowth and the bone healing process. In addition, the bone adhesives exhibited favorable mineralization capability, biocompatibility, and osteogenic activity. In vivo experiments showed that it has a better bone-healing effect compared with the traditional polymethyl methacrylate bone cement. These results demonstrate that the bone adhesive has great potential in the treatment of bone fractures.

Effect of Membrane Fixation and the Graft Combinations on Horizontal Bone Regeneration: Radiographic and Histologic Outcomes in a Canine Model.

The aim of this study was to determine the effect of membrane fixation and combinations of bone substitute materials and barrier membranes on horizontal bone regeneration in peri-implant defects. Eight mongrel dogs underwent chronic buccal peri-implant dehiscence defects creation and were randomized into 4 groups: (a) deproteinized bovine bone mineral 1 (DBBM1) with a native collagen membrane (CM) (BB group, positive control group), (b) DBBM1 with native CM and 2 fixation pins (BBP group), (c) DBBM2 with a cross-linked CM (XC group), and (d) DBBM2 with cross-linked CM and 2 fixation pins (XCP group). Following 16 weeks of healing, tissues were radiographically and histomorphometrically analyzed. The total augmented area was significantly larger in the BBP, XC, and XCP groups compared to the BB group (4.27 ± 3.21, 7.17 ± 7.23, and 6.91 ± 5.45 mm2 versus 1.35 ± 1.28 mm2, respectively; P = 0.022). No significant difference for the augmented tissue thickness was observed among the 4 groups. The augmented tissue thickness measured at 3 mm below the implant shoulder was higher in BBP, XC, and XCP than that in BB (2.43 ± 1.53, 2.62 ± 1.80, and 3.18 ± 1.96 mm versus 0.80 ± 0.90 mm, respectively), trending toward significance (P = 0.052). DBBM2 and a cross-linked CM were significantly more favorable for horizontal bone regeneration compared to DBBM1 and a native CM. However, when DBBM1 and a native CM were secured with fixation pins, outcomes were similar. The addition of pins did not lead to more favorable outcomes when a cross-linked CM was used.

Transmetacarpal replantation

Introduction. Transmetacarpal amputation (TA) distal to the superficial palmar arch is one of the most difficult procedures in replantation surgery because it requires the reconstruction of blood vessels, muscles, tendons, bones, nerves, and skin. We present a case of a patient with TA of the left hand and microsurgical replantation. Case report. A 23-year-old left-hand dominant male worker with a positive smoking history sustained TA from a radial saw blade and avulsion injury of the palmar side of the thumb with no other apparent injuries. The time between the amputation and replantation was 4 hrs. The patient sustained the amputation at the level of metacar-pophalangeal joints. The successful replantation included: wound and intrinsic muscles debridement, microvascular anastomoses of the blood vessels, internal fixation of the metacarpal bones, neurorrhaphy, tenorrhaphy, and wound closure with local skin flap for thumb soft tissue defect. The patient was followed for seven years postoperatively. Conclusion. The replantation surgery requires a specialized department and well-educated teams of hand microsurgeons, orthopedic surgeons, and anesthesiologists. The most imortant factors that influenced the outcome after the replantation in the presented case included the type and level of injury, ischemia time, comorbidities, age, smoking history, and physical therapy.

Study of the Degradation Rate of Polymeric Biodegradable Composites PLA (Powder) – PCL Produced by Solvent Casting in 0.3% NaCl Medium

The treatment of long-standing fractures is influenced by trauma, resorption, and bone pathology. Additional issues arise with the use of non-biodegradable metal implants, requiring additional procedures for removal, increasing the risk of infection, complications, and prolonging recovery time. The solution being studied is the use of biodegradable materials such as Polylactic Acid (PLA) - Polycaprolactone (PCL) polymers for bone repair and fixation, which can reduce the risk of complications and infection while accelerating healing. This research aims to analyze the effect of PLA powder percentage on the degradation rate of PCL mixtures using the solvent casting method. The specimen preparation process in this study utilizes the solvent casting method by mixing PLA and PCL using acetone as a solvent. The PLAPCL compositions used are 10 PLA: 90 PCL, 30 PLA: 70 PCL, and 50 PLA: 50 PCL. The specimens are then characterized through density and degradation testing by immersing them in a 0.9% NaCl infusion solution. The density testing results indicate that the 50 PLA: 50 PCL composition has the highest density, at 0.97 g/cm³. In degradation testing, the 10 PLA: 90 PCL composition exhibits the highest degradation rate, with a weight loss percentage of 22.01% in the fourth week and a degradation rate of 0.0128 mmpy in the first week.

Expert consensus on Prospective Precision Diagnosis and Treatment Strategies for Osteoporotic Fractures.

Osteoporotic fractures are the most severe complications of osteoporosis, characterized by poor bone quality, difficult realignment and fixation, slow fracture healing, and a high risk of recurrence. Clinically managing these fractures is relatively challenging, and in the context of rapid aging, they pose significant social hazards. The rapid advancement of disciplines such as biophysics and biochemistry brings new opportunities for future medical diagnosis and treatment. However, there has been limited attention to precision diagnosis and treatment strategies for osteoporotic fractures both domestically and internationally. In response to this, the Chinese Medical Association Orthopaedic Branch Youth Osteoporosis Group, Chinese Geriatrics Society Geriatric Orthopaedics Committee, Chinese Medical Doctor Association Orthopaedic Physicians Branch Youth Committee Osteoporosis Group, and Shanghai Association of Integrated Traditional Chinese and Western Medicine Osteoporosis Professional Committee have collaborated to develop this consensus. It aims to elucidate emerging technologies that may play a pivotal role in both diagnosis and treatment, advocating for clinicians to embrace interdisciplinary approaches and incorporate these new technologies into their practice. Ultimately, the goal is to improve the prognosis and quality of life for elderly patients with osteoporotic fractures.

Influence of Preheat Temperature Variation on Single Screw Extrusion for Characterizing PLA, PCL, and HA Biocomposite Filaments

Fractures and ligament injuries often require bone fixation, commonly through Open Reduction and Internal Fixation (ORIF) with compression plates and screws. Additive manufacturing (AM) techniques are considered sustainable due to their potential to reduce emissions and have a minimal adverse impact on the environment. Currently, there is extensive research into producing biocomposite filaments, though there remains limited exploration of the impact of preheat temperature on filament properties. This research explores the effects of varying preheat temperatures in a single screw extruder to achieve biocomposite filament as candidate for biodegradable bone implants. Biocomposite filaments made from Polylactic Acid (PLA) and Polycaprolactone (PCL) in an 85:15 ratio, with 5% hydroxyapatite (HA) derived from green mussel shell waste. Biocomposite mixture was cut into sub-5mm fragments and extruded at 175°C with preheat temperatures between 159°C and 168°C. Filaments were used to fabricate specimens via a 3D printer, following ASTM D790 standards. Specimens were analyzed using X-Ray Diffractometer, Fourier Transform Infrared, Scanning Electron Microscope, density measurements, three-point bending tests, and biodegradation assessments. Results show that preheat temperature variations significantly affect the filament’s crystallinity index, impacting density and mechanical properties. Higher preheat temperatures result in a lower crystallinity index, decreasing density and potentially increasing degradation rates.