Bone Plate Research Articles

Biomechanical characteristics of maxillary anterior incisor, conventional immediate implantation and socket shield technique — A finite element analysis and case report

BackgroundTo prevent the absorption and collapse of the labial bone plate of the anterior teeth, immediate implantation and socket shield technique have been increasingly applied to anterior dental aesthetic implant restoration. ObjectiveTo provide a biomechanical basis for implant restoration of maxillary anterior teeth, finite element analysis was used to investigate the stress peak and distribution in different anatomical sites of natural teeth, conventional immediate implantation and socket shield technique. MethodsThree maxillary finite element models were established, including a maxillary incisor as a natural tooth, a conventional immediate implantation and a socket shield technique. A mechanical load of 100 N was applied to simulate and analyze the biomechanical behavior of the root, periodontal ligament (PDL), implant and surrounding bone interface. ResultsThe stress distribution of the natural tooth was relatively uniform under load. The maximum von Mises stress of the root, periodontal ligament, cortical bone and cancellous bone were 20.14 MPa, 2.473 MPa, 19.48 MPa and 5.068 MPa, respectively. When the conventional immediate implantation was loaded, the stress was mainly concentrated around the neck of implant. Maximum stress on the surface of the implant was 102 MPa, the cortical bone was 16.13 MPa, and the cancellous bone was 18.29 MPa. When the implantation with socket shield technique was loaded, the stress distribution of the implant was similar to that of immediate implantation. Maximum stress on the surface of the implant was 100.5 MPa, the cortical bone was 23.11 MPa, the cancellous bone was 21.66 MPa, the remaining tooth fragment was 29.42 MPa and the periodontal ligament of the tooth fragment was 1.131 MPa. Conclusions1. Under static loading, both socket shield technology and conventional immediate implantation can support the esthetic restoration of anterior teeth biomechanically. 2.Under short-term follow-up, both immediate implant and socket shield technology achieved satisfactory clinical results, including bone healing and patient satisfaction. 3.The stress distribution is mainly located on the buccal bone surface of the implant and is associated with resorption of the buccal bone plate after implant replacement in both socket shield technology and conventional immediate implantation. 4.The presence of retained root fragment had an impact on the bone graft gap. In immediate implantation, the peak stress was located in the cortical bone near the implant position, while in socket shield technology, the peak stress was at the neck of the cortical bone corresponding to the retained root fragment.

Effect of genetically engineered drugs in aseptic necrosis of the femoral head in rats

Bone tissue is a dynamic structure with a metabolic function. The maintenance of bone homeostasis is carried out due to the continuous process of its renewal, remodeling. At the same time, a number of pathological processes, such as ischemic catastrophe, can lead to a violation of the balance of maintaining the constancy of the bone structure. One of these diseases is aseptic necrosis of the femoral head. The presented study analyzes the dynamics of expression of genes involved in maintaining bone tissue homeostasis, changes in the histological picture during the development of aseptic necrosis of the femoral head in laboratory rats that did not receive genetically engineered drugs and against the background of the use of inhibitors of biological action IL-6, TNF-α. After induction of aseptic necrosis in the proximal epiphysis of the femur, the histological picture in animals of different groups was not the same. More preserved bone architectonics and a larger volume of bone plates were recorded in rats receiving genetically engineered drugs compared to animals without the introduction of biological agents. The latter also had the most vivid picture of osteodestruction with increased expression of proinflammatory cytokine genes. In animals, against the background of the use of drugs of inhibitors of the biological action of IL-6, TNF-α, from the second week after induction of aseptic necrosis of the mRNA, the profile of the spongiose bone of the proximal epiphysis of the femur tended to increase the expression of osteoreparation genes. At the same time, the greatest inhibition of osteoclastogenesis gene expression was obtained in rats after injection of a monoclonal antibody to the IL-6 receptor.

Enhancement in the impact and torsional properties of 3D‐printed biocompatible poly(lactic acid) locking bone plates: sustainable integration into healthcare applications

Enhancement in the impact and torsional properties of <scp>3D‐</scp>printed biocompatible poly(lactic acid) locking bone plates: sustainable integration into healthcare applications

Cortical bone plate properties assessment using inversion of axially transmitted low frequency ultrasonic guided waves.

Over the past few decades, early osteoporosis detection using ultrasonic bone quality evaluation has gained prominence. Specifically, various studies focused on axial transmission using ultrasonic guided waves and have highlighted this technique's sensitivity to intrinsic properties of long cortical bones. This work aims to demonstrate the potential of low-frequency ultrasonic guided waves to infer the properties of the bone inside which they are propagating. A proprietary ultrasonic transducer, tailored to transmit ultrasonic guided waves under 500 kHz, was used for the data collection. The gathered data underwent two-dimensional fast Fourier transform processing to extract experimental dispersion curves. The proposed inversion scheme compares experimental dispersion curves with simulated dispersion curves calculated through the semi-analytical iso-geometric analysis (SAIGA) method. The numerical model integrates a bone phantom plate coupled with a soft tissue layer on its top surface, mimicking the experimental bone phantom plates. Subsequently, the mechanical properties of the bone phantom plates were estimated by reducing the misfit between the experimental and simulated dispersion curves. This inversion leaned heavily on the dispersive trajectories and amplitudes of ultrasonic guided wave modes. Results indicate a marginal discrepancy under 5% between the mechanical properties ascertained using the SAIGA-based inversion and those measured using bulk wave pulse-echo measurements.

Effectiveness of bone plate reduction combined with resorbable plate fixation in the treatment of large mandibular cysts.

This study aims to observe the clinical effect of bone plate reduction in combination with a resorbable plate on large mandibular cysts. Between October 2017 and September 2022, patients with large mandibular cysts in the presence of labial and buccal cortical bone were involved in the study. Intraoral approach was performed for bone plate reduction. Cone beam computed tomography (CBCT) scan was reviewed at 3, 6, and 9 months postoperatively to observe postoperative complications. Osteogenic results were assessed at these times to determine the clinical outcomes of this procedure. Eleven cases with large mandibular cysts in the presence of cortical bone were evaluated. The average thickness of the cortical bone on the labial and buccal sides was measured to be about (1.98±0.37) mm before surgery, with a mean value of (0.73±0.17) mm at the thinnest part of the plate and up to 0.51 mm at the thinnest part of the plate. The cystic cavities were well revealed during the surgeries, which were completed successfully. Postoperatively, the wounds healed in one stage without infection. The percentages of cyst shrinkage were 20.01%, 41.76%, and 73.41% at 3, 6, and 9 months after surgery, respectively. Quantitative measurement of bone mineral density in the jaws by CBCT with MIMICS software. The bone mineral densities of the adult bone were 313.78, 555.85, and 657.45 HU at the 3, 6, and 9 month time intervals, respectively. No significant change in the patient's maxillofacial appearance were observed from the preoperative period as assessed by the patient's and observer's visual analog scale. Bone plate reduction is an effective treatment for large mandibular cysts of the oral and maxillofacial region with the presence of cortical bone.

The cost of care in maxillofacial fractures treatment in relation to the type of fixation and length of stay at a tertiary care hospital of Karachi, Pakistan: A retrospective chart review.

In addition to the clinical burden of trauma, the financial burden is an important aspect of care globally, especially for patients in low- and middle-income countries. The current retrospective review was done of data from January 2015 to December 2020 related to patients of oral maxillofacial trauma management in a tertiary care setting. Analysis of variance was used to determine the mean difference in the cost incurred depending upon the type of trauma and the number of bone plates used in fracture management. Pearson correlation was applied to explore any correlation involving patient age, aetiology and type of fracture, number of bone plates employed and the length of stay in the hospital. No statistically significant differences were noted in the cost among the different groups. The cost of care was significantly (p<0.001) correlated to the length of stay. Other variables, such as the type of fractures and the number of plates, had no significant impact (p>0.05).

Save the subchondral bone plate: Debridement versus bone marrow stimulation in acetabular cartilage defects over 60 months of follow-up.

Bone marrow stimulation is a common treatment for full-thickness cartilage defects in the hip joint. However, common procedures may result in poor fibrous repair tissue and changes to the subchondral anatomy. This study investigated the clinical outcome of a cohort of International Cartilage Repair Society (ICRS) grades 3 and 4 cartilage defects treated with bone marrow stimulation compared to those who received simple debridement/chondroplasty. In this retrospective registry study, 236 patients with uni-focal acetabular chondral lesions of the hip up to 400 mm² (mean 177.4 ± 113.4 mm²) and of ICRS grade ≥3 with follow-up of at least 12 months (mean 33.2 ± 15.3 months) were included. Eighty-one patients underwent bone marrow stimulation (microfracture: n = 44, abrasion: n = 37) besides treatment of the underlying pathology, 155 patients underwent defect debridement/chondroplasty. The patient-reported outcome was measured using the International Hip Outcome Tool 33 (iHOT33) score and the Visual Analogue Scale (VAS) for pain. iHOT33 and VAS both improved highly statistically significantly (p < 0.001) in the debridement group after 6, 12, 24, 36 and 60 months compared to the preoperative scores, whereas iHOT33 and VAS after microfracture or abrasion did not show statistically significant changes over time. Twenty-four and sixty months postsurgery the debridement group revealed significant higher scores in the iHOT33 compared to the bone marrow stimulation groups. Patients with chondral lesions of the hip ≤400 mm2 sustainably benefit from arthroscopic debridement under preservation of the subchondral bone plate in terms of functional outcome and pain in contrast to patients treated with bone marrow stimulation. These findings discourage the currently recommended use of microfracture in the hip joint. Level III.

Oral Health Assessment in Cleft Lip & Palate Patients During Orthodontic Treatment for Maxillary Protraction: A Periodontal & Microbiological Study.

To assess the oral health status and microbiota of subgingival plaque in patients with surgically repaired cleft lip and palate (CLP) during orthodontic treatment for maxillary protraction with two different orthodontic appliances. Randomized controlled trial. Institutional. A total of 90 patients with surgically repaired Unilateral Cleft Lip and Palate, out of initially enrolled 120 patients, were divided into 3 groups: experimental group I, experimental group II and control group, with 30 subjects each. Patients with a history of oral prophylaxis in last 6 months or antibiotic therapy within 3 months were excluded from the study. Bone Anchored Maxillary Protraction was done in experimental group I, while facemask with acrylic occlusal splint was used for maxillary protraction in experimental group II and no orthodontic intervention in control group. Plaque Index (PI), Gingival Index (GI), Gingival Bleeding Index (GBI), Probing Depth (PD), and microbiota of subgingival plaque (P. gingivalis, P. intermedia, Veillonella and Capnocytophaga) were compared at baseline (T0) and after 8 months (T1). The PI, GI, GBI and PD were observed to be significantly higher in experimental group II followed by experimental group I as compared to control group at 8 months interval (P < .001). The microbiota counts increased significantly in experimental group II and experimental group I (P < .001), as compared to control group. Maxillary protraction with facemask and bone plates was found to be a better alternative than facemask with occlusal splint, considering the overall oral health of patients with CLP.

The Lateral Wall of the Inferior Meatus as a New Graft Source for Rhinoplasty: Radiological Study and Surgical Technique.

Generally, revision rhinoplasty cases require the use of stiff grafts to restore the lost support. However, the majority of patients indicated for revision surgery present with a lack of a bony cartilaginous framework of the septum, especially after previous septoplasty. Thus, surgeons are compelled to harvest costal cartilage. At the same time, rib graft harvesting is associated with additional trauma and a risk of serious complications. Being ENT surgeons, we often resect a part of the lateral wall of the inferior nasal meatus during the extended endoscopic approach to the maxillary sinus. We supposed that this bone plate could be used as a donor site for rhinoplasty graft harvesting. The aim of our study was a radiological assessment of the feasibility and limits of using the inferior meatus lateral wall (IMLW) as a donor site for rhinoplasty bone graft.A retrospective evaluation of 100 CT scans of sinuses was conducted. Further measurements of the IMLW were performed: average length and width (28.06 ± 4.03 mm and 19.73 ± 3.08 mm, respectively), thickness (0.62 ± 0.21 mm), and average deviation from the sagittal plane (17.7 ± 9.53 degrees). According to the obtained measurements, the described donor site is appropriate for harvesting nice straight bony fragments.The IMLW bone graft was used in four revision rhinoplasty cases. There were no postoperative complications. During the long-term follow-up, patients reported significant improvement in aesthetics, function, and social aspects according to Rhinoplasty Outcome Evaluation. Thus, the described technique is an easy and safe method for bone harvesting for revision rhinoplasty. Our first experience demonstrated the convenience and stability of IMLW grafts for revision rhinoplasty during the follow-up period of up to 2 years.

Removing Artifacts in Transcranial Photoacoustic Imaging With Polarized Self-Attention Dense-UNet

ObjectivePhotoacoustic imaging (PAI) is a promising transcranial imaging technique. However, the distortion of photoacoustic signals induced by the skull significantly influences its imaging quality. We aimed to use deep learning for removing artifacts in PAI. MethodsIn this study, we propose a polarized self-attention dense U-Net, termed PSAD-UNet, to correct the distortion and accurately recover imaged objects beneath bone plates. To evaluate the performance of the proposed method, a series of experiments was performed using a custom-built PAI system. ResultsThe experimental results showed that the proposed PSAD-UNet method could effectively implement transcranial PAI through a one- or two-layer bone plate. Compared with the conventional delay-and-sum and classical U-Net methods, PSAD-UNet can diminish the influence of bone plates and provide high-quality PAI results in terms of structural similarity and peak signal-to-noise ratio. The 3-D experimental results further confirm the feasibility of PSAD-UNet in 3-D transcranial imaging. ConclusionPSAD-UNet paves the way for implementing transcranial PAI with high imaging accuracy, which reveals broad application prospects in preclinical and clinical fields.

Associations between the keratinized mucosa width and the underlying alveolar bone dimensions at partial edentulous molar sites: a retrospective cross-sectional study

BackgroundThe assessment of hard and soft tissue at edentulous sites is important for subsequent implant treatment design. The aim of the present study was to explore the associations between the keratinized mucosa width (KMW) and the underlying alveolar bone dimensions at partial edentulous molar sites.MethodsIn this retrospective study, a total of 110 patients with at least one missing molar were selected. The buccal KMW of the edentulous molar sites was evaluated. Cone-beam computed tomography scans were collected, and the height discrepancy between the alveolar crest and the buccal bone plate (HC−B) as well as the alveolar bone height (ABH) were measured. The KMW was compared among the HC−B and ABH groups at both maxillary and mandibular sites. Linear regression and generalized estimation equations (GEEs) were used to explore the associations between the KMW and alveolar bone dimensions at α = 0.05.ResultsAmong the 110 patients, 158 edentulous molar sites were analyzed. The average HC−B and ABH were significantly lower at the maxillary sites (1.26 ± 1.62 mm, 11.62 ± 3.94 mm) than at the mandibular sites (3.67 ± 2.85 mm, 14.91 ± 3.01 mm, p < 0.001). The KMW was significantly lower at sites with HC−B > 2 mm than at sites with HC−B ≤ 2 mm both in the maxilla and mandible (p < 0.001). No significant differences were found between the KMW at sites with ABH < 10 mm and sites with ABH ≥ 10 mm (p > 0.05). Linear regression and GEEs analyses revealed that the HC−B was significantly associated with the KMW (B = -0.339, p < 0.001), while the association between the KMW and the ABH was not statistically significant (B = -0.046, p = 0.352).ConclusionsThe buccal KMW at edentulous molar sites was significantly associated with the HC−B. Alveolar ridges presenting with a sloped configuration were more prone to possess a narrower band of keratinized mucosa. Both hard and soft tissue augmentation should be considered for implant treatment at these sites. The correlations of dynamic changes between the KMW and alveolar bone dimensions after tooth extraction should be further investigated.

On the Conservation Laws and Traveling Wave Solutions of a Nonlinear Evolution Equation that Accounts for Shear Strain Waves in the Growth Plate of a Long Bone

On the Conservation Laws and Traveling Wave Solutions of a Nonlinear Evolution Equation that Accounts for Shear Strain Waves in the Growth Plate of a Long Bone

Advantages of cone beam computed tomography for evaluation of subchondral insufficiency fractures of the knee compared to MRI

To determine the diagnostic yield of cone beam computed tomography (CBCT) compared with 3 T magnetic resonance imaging (MRI) for the evaluation of subchondral insufficiency fractures of the knee. Consecutive patients with subchondral insufficiency fractures of the knee examined by 3 T MRI and CBCT of the femoral condyles were reviewed. Two experienced raters graded the lesion severity on 3 T MRI and CBCT images: grade 1: no signs of a subchondral bone lesion; grade 2: subchondral trabecular fracture or cystic changes, but without infraction of the subchondral bone plate; grade 3: collapse of the subchondral bone plate. Ratings were repeated after six weeks to determine reliability. In addition, the bone lesion size was measured as elliptical area (mm2) and compared between CBCT and T1-weighted MRI sequences. Among 30 patients included (43.3% women; mean age: 60.9 ± 12.8 years; body mass index (BMI) 29.0 ± 12.8 kg/m2), the medial femoral condyle was affected in 21/30 patients (70%). The grading of subchondral lesions between MRI and CBCT did not match in 12 cases (40%). Based on MRI images, an underestimation (i.e., undergrading) compared with CBCT was observed in nine cases (30%), whereas overgrading occurred in three cases (10%). Compared to CBCT, routine T1-weighted 3 T sequences significantly overestimated osseus defect zones in sagittal (84.7 ± 68.9 mm2 vs. 35.9 ± 38.2 mm2, p < 0.01, Cohen’s d = 1.14) and coronal orientation (53.1 ± 24.0 mm2 vs. 22.0 ± 15.2 mm2, p < 0.01, Cohen’s d = 1.23). The reproducibility of the grading determined by intra- and inter-rater agreement was very high in MRI (intra-class correlation coefficient (ICC) 0.78 and 0.90, respectively) and CBCT (ICC 0.96 and 0.96, respectively). In patients with subchondral insufficiency fractures of the knee, the use of CBCT revealed discrepancies in lesion grading compared with MRI. These findings are clinically relevant, as precise determination of subchondral bone plate integrity may influence the decision about conservative or surgical treatment. CBCT represents our imaging modality of choice for grading the lesion and assessing subchondral bone plate integrity. MRI remains the gold standard modality to detect especially early stages.

Injury to Anatomic Structures Due to Fixation Device in Management of Mandibular Fracture.

ORIF is the gold standard for the management of mandibular fractures. The chances of postoperative complications are due to infection, damage of the inferior alveolar nerve canal, or tooth root during the fixation of the fracture fragments. Fixation hardware placed in the vicinity of the vital structures may encroach on the anatomic structures, leading to postoperative complications. The aim of this study is to evaluate the injury to the anatomic structures in the proximity of the fracture line due to the fixation device. This retrospective study was conducted in a tertiary care teaching hospital from July 2021 to June 2023. The cases of maxillofacial trauma reported and referred from peripheral centers were considered duly, applying the inclusion and exclusion criteria. Patients having mandibular fractures from one mandibular foramen to another with or without associated other facial fractures were treated by ORIF under general anesthesia. The patient was followed up at 1 week, 1 month, 3 months, and 6 months. The cases of postoperative complications were further investigated by CBCT. There were 67 patients (56 males and 11 females) with 86 fracture lines in the age group of 18-55 years with an average age of 35.2 years. Postoperatively 7 patients presented with unilateral paresthesia of the lower lip and chin region. CBCT revealed that the mean distance of the screw from the inferior alveolar nerve canal was 3.02mm. None of these cases had injury to the nerve canal or roots of teeth. All the patients recovered from paresthesia within 6 months. Complications like injury to the inferior alveolar nerve (IAN) with sensory disturbances to the lower lip and chin, as well as tooth/tooth root fractures, may occur due to mandibular fracture, surgical manipulation, and fixation devices. The anatomic structures in the vicinity of the fracture line can be damaged during the fixation of the fracture fragments by the bone plates and screws. In the present study, it was found that 7 out of 67 patients presented with unilateral paresthesia of the lower lip and chin. CBCT analysis showed a considerable distance of 3.02mm from the inferior alveolar nerve canal to the screws. There was no evidence of hardware encroachment on the IAN or tooth roots. Selection and placement of appropriate fixation devices, particularly the length of the bone screws, are crucial to avoid injury to the anatomic structures.

Supraorbital Ethmoid Air Cell - Its Role in Sinonasal Pathologies.

The supraorbital ethmoid air cell (SOEC) is an anatomical variation of the ethmoid air cell system that pneumatizes the orbital plate of the frontal bone. It affects the frontal recess configuration by opening posterior and lateral to the frontal sinus ostium. This cross-sectional observational study includes 100 patients with Supra orbital ethmoid air cells including various pathologies. We picked up the first 100 patients who had SOEC in all the CT PNS done for various sinonasal pathologies. The incidence of the cell was about 43%. The most common type was the cell extending up to the medial wall of the orbit which was noted in 37% of the cases. Cribriform plate was low-lying in patients with SOEC and the most common type was Keros 3 in about 49% of the study group. 83 patients had anterior ethmoid artery (AEA) lying away from the skull base hanging freely in the mesentery. The most common pathologies observed in patients with supraorbital ethmoid cells were chronic rhinosinusitis followed by mucoceles. The recurrence rate of sinusitis is high in patients with SOEC. The recurrences were mostly because of mistaking the SOEC to be frontal sinus or incomplete removal of partition between them. study stresses the importance of SOEC and its orientation preoperatively to avoid complications during and after the surgery. Detailed preoperative evaluation with the CT helps the surgeon to identify the cells, their extent and associated anatomical variations thereby preventing damage to AEA, cribriform plate and lateral lamella and can get good results.

Structural design and evaluation of bone remodeling effect of fracture internal fixation implants with time-varying stiffness

The stiffness of an ideal fracture internal fixation implant should have a time-varying performance, so that the fracture can generate reasonable mechanical stimulation at different healing stages, and biodegradable materials meet this performance. A topology optimization design method for composite structures of fracture internal fixation implants with time-varying stiffness is proposed, considering the time-dependent degradation process of materials. Using relative density and degradation residual rate to describe the distribution and degradation state of two materials with different degradation rates and elastic modulus, a coupled mathematical model of degradation simulation mechanical analysis was established. Biomaterial composite structures were designed based on variable density method to exhibit time-varying stiffness characteristics. Taking the bone plate used for the treatment of tibial fractures as an example, a composite structure bone plate with time-varying stiffness characteristics was designed using the proposed method. The optimization results showed that material 1 with high stiffness formed a columnar support structure, while material 2 with low stiffness was distributed at the degradation boundary and inside. Using a bone remodeling simulation model, the optimized bone plates were evaluated. After 11 months of remodeling, the average elastic modulus of callus using degradable time-varying stiffness plates, titanium alloy plates, and stainless steel plates were 8 634 MPa, 8 521 MPa, and 8 412 MPa, respectively, indicating that the use of degradable time-varying stiffness plates would result in better remodeling effects on the callus.

Lesion Distribution in the Metacarpophalangeal and Metatarsophalangeal Region of 341 Horses Using Standing Magnetic Resonance Imaging.

Pain localised to the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) region represents a frequent cause of lameness in sport horses, and standing magnetic resonance imaging (MRI) of these regions is increasingly being acquired. This multicentre retrospective study describes the ranges of abnormalities identified on standing MRI of the MCP/MTP region and compares patterns of abnormalities between forelimbs, hindlimbs and different sports disciplines. In total, 341 MRI reports were reviewed. Subchondral bone plate irregularities, condylar and proximal phalanx pathologies were frequently identified with subchondral bone defect, sclerosis and increased intensity on STIR images often described. Medial pathology was frequently identified in the forelimbs, and more lateral pathology was reported in the hindlimbs, which could potentially reflect differences in the loading patterns. Significant differences in MRI findings were found between different sports activities, with MCP/MTP bone pathology occurring more frequently in MRI reports from race and endurance horses and MCP/MTP soft tissue injuries being reported more frequently in dressage and show-jumping horses, particularly in the suspensory apparatus, including the distal sesamoidean ligaments. The findings of this study identify patterns of MCP/MTP abnormalities detected using standing MRI, with differences seen between forelimbs and hindlimbs and between different sports disciplines.

Development and Evaluation of an AZ31 Magnesium Alloy and Eggshell Powder Composite for Orthopedic Surgical Implants

This research investigates the development and evaluation of a novel composite material composed of AZ31 magnesium alloy and eggshell powder, designed for use in surgical bone implants. The primary objective is to enhance the mechanical properties and biocompatibility of AZ31 by incorporating eggshell powder, which is known for its hardness and strength. The composite is fabricated using the stir casting technique, where the molten magnesium is mixed with finely ground eggshell powder to achieve uniform dispersion. The resulting samples are subjected to rigorous mechanical testing, including tensile and compressive strength evaluations, as well as hardness measurements. Additionally, the internal structure and particle distribution of the composite are analyzed using scanning electron microscopy and X-ray diffraction, respectively. This study aims to provide a comprehensive understanding of the material properties and structural characteristics of the composite, with a focus on its potential applications in orthopedic load-bearing implants and fixation devices, such as bone plates, joint replacements, screws, rods, dental implants, and cardiac stents. The findings are expected to contribute to the development of improved biomaterials for medical applications, leveraging the unique benefits of both magnesium alloy and eggshell powder.

Aging alters the subchondral bone response 7 days after noninvasive traumatic joint injury in C57BL/6JN mice.

Posttraumatic osteoarthritis (PTOA) commonly develops following anterior cruciate ligament (ACL) injuries, affecting around 50% of individuals within 10-20 years. Recent studies have highlighted early changes in subchondral bone structure after ACL injury in adolescent or young adult mice, which could contribute to the development of PTOA. However, ACL injuries do not only occur early in life. Middle-aged and older patients also experience ACL injuries and PTOA, but whether the aged subchondral bone also responds rapidly to injury is unknown. This study utilized a noninvasive, single overload mouse injury model to assess subchondral bone microarchitecture, turnover, and material properties in both young adults (5 months) and early old age (22 months) female C57BL/6JN mice at 7 days after injury. Mice underwent either joint injury (i.e., produces ACL tears) or sham injury procedures on both the loaded and contralateral limbs, allowing evaluation of the impacts of injury versus loading. The subchondral bone response to ACL injury is distinct for young adult and aged mice. While 5-month mice show subchondral bone loss and increased bone resorption postinjury, 22-month mice did not show loss of bone structure and had lower bone resorption. Subchondral bone plate modulus increased with age, but not with injury. Both ages of mice showed several bone measures were altered in the contralateral limb, demonstrating the systemic skeletal response to joint injury. These data motivate further investigation to discern how osteochondral tissues differently respond to injury in aging, such that diagnostics and treatments can be refined for these demographics.

Experience in early minimally invasive fixation of pubic symphysis disruption with a system of transpedicular screws in patients with combined pelvic trauma (pilot study)

Introduction Challenges of treating the injuries of pubic symphysis in patients with combined pelvic injury require developing new techniques for stable minimally invasive osteosynthesis in the acute period of trauma.Purpose of the work was to assess the application of low invasive fixation of the pubic symphysis with a system of transpedicular screws in the patients with combined unstable pelvic injuries in the acute period of the traumatic disease.Materials and methods The results of treatment of 12 patients with polytrauma with unstable pelvic injury with rupture of the pubic symphysis who were treated at Dzhanelidze Research Institute of Emergency Medicine, St. Petersburg, in the period from 2017 to 2023, were analyzed. All the patients underwent final minimally invasive fixation of the pubic symphysis with a system of transpedicular screws in the early period of the traumatic disease.Results The overall assessment of the results in 12 patients found no complications or technical errors during the installation of transpedicular screws. Control CT scans of the pelvis showed that osteosynthesis was stable in all patients, and the position of metal was correct in all. One patient from the study group died in the clinic from massive pulmonary embolism. The long-term results in 11 patients in the period from 6 months to 3 years after trauma were evaluated as excellent and good anatomical and functional results in 10 patients, one case had fair outcome.Discussion The use of bone plates to fix ruptures of the symphysis pubis leads to disruption of its physiological mobility, and the patient’s activity in the postoperative period can cause an implant fracture. Original dynamic plates and wire cerclage help avoid this complication; however, all these techniques involve significant surgical trauma and blood loss, as well as the risk of postoperative wound suppuration. Minimally invasive methods of fixation using cannulated screws, systems such as Endobutton, Tight Rope can reduce intraoperative trauma and the risk of complications (blood loss, suppuration); however, the procedure for their installation is quite complex and lengthy, and for greater stability, external fixation of the pelvic ring is often required. The proposed minimally invasive fixation of the pubic symphysis with a system of transpedicular screws avoids a lot of shortcomings and is sufficiently stable.Conclusion The method of minimally invasive fixation of the pubic symphysis with a system of transpedicular screws meets current requirements in the treatment of patients with polytrauma and unstable pelvic injury, and it may be successfully used in the acute period of trauma.