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Objective: This study aimed to evaluate the effectiveness of biomaterials in bone healing of critical bone defects created by piezoelectric surgery in rat calvaria. Method and materials: Histomorphologic analysis was performed to assess bone regeneration and tissue response. Fifty animals were randomized into five groups with one of the following treatments: Control group (n = 10), spontaneous blood clot formation with no bone fill; BO group (Bio-Oss, Geistlich Pharma; n = 10), defects were filled with bovine medullary bone substitute; BF group (Bonefill, Bionnovation; n = 10), defects were filled with bovine cortical bone substitute; hydroxyapatite group (n = 10), defects were filled with hydroxyapatite; calcium sulfate group (n = 10), defects were filled with calcium sulfate. Five animals from each group were euthanized at 30 and 45 days. The histomorphometry calculated the percentage of the new bone formation in the bone defect. Results: All data obtained were evaluated statistically considering P < .05 as statistically significant. The results demonstrated the potential of all biomaterials for enhancing bone regeneration. The findings showed no statistical differences between all the biomaterials at 30 and 45 days including the control group without bone grafting. Conclusion: In conclusion, the tested biomaterials presented an estimated capacity of osteoconduction, statistically nonsignificant between them. In addition, the selection of biomaterial should consider the specific clinical aspect, resorption rates, size of the particle, and desired bone healing responses. It is important to emphasize that in some cases, using no bone filler might provide comparable results with reduced cost and possible complications questioning the very frequent use of ridge presentation procedures. [ABSTRACT FROM AUTHOR]

Fractures continue to be a global economic burden as there are currently no osteoanabolic drugs approved to accelerate fracture healing. In this study, we aimed to develop an osteoanabolic therapy which activates the Wnt/β-catenin pathway, a molecular driver of endochondral ossification. We hypothesize that using an mRNA-based therapeutic encoding β-catenin could promote cartilage to bone transformation formation by activating the canonical Wnt signaling pathway in chondrocytes. To optimize a delivery platform built on recent advancements in liposomal technologies, two FDA-approved ionizable phospholipids, DLin-MC3-DMA (MC3) and SM-102, were used to fabricate unique ionizable lipid nanoparticle (LNP) formulations and then tested for transfection efficacy both in vitro and in a murine tibia fracture model. Using firefly luciferase mRNA as a reporter gene to track and quantify transfection, SM-102 LNPs showed enhanced transfection efficacy in vitro and prolonged transfection, minimal fracture interference and no localized inflammatory response in vivo over MC3 LNPs. The generated β-cateninGOF mRNA encapsulated in SM-102 LNPs (SM-102-β-cateninGOF mRNA) showed bioactivity in vitro through upregulation of downstream canonical Wnt genes, axin2 and runx2. When testing SM-102-β-cateninGOF mRNA therapeutic in a murine tibia fracture model, histomorphometric analysis showed increased bone and decreased cartilage composition with the 45 μg concentration at 2 weeks post-fracture. μCT testing confirmed that SM-102-β-cateninGOF mRNA promoted bone formation in vivo, revealing significantly more bone volume over total volume in the 45 μg group. Thus, we generated a novel mRNA-based therapeutic encoding a β-catenin mRNA and optimized an SM-102-based LNP to maximize transfection efficacy with a localized delivery.

BackgroundProvisional stabilization of high-energy tibia fractures using temporary plate fixation (TPF) or external fixation (ex-fix) prior to definitive medullary nailing (MN) is a strategy common in damage control orthopaedics. There is a lack of comprehensive data evaluating outcomes between these methods. This study compares outcomes of patients stabilized with either TPF or ex-fix, and with early definitive MN only, assessing complications including nonunion and deep infection.MethodsA retrospective review was performed on adult patients with tibia fractures treated with MN followed until fracture union (≥3 months) at a single level-1 trauma center from 2014 to 2022. Medical records were evaluated for nonunion and deep infection. Demographics, injury characteristics, and fixation methods were recorded. Significance between patients who underwent TPF and ex-fix was compared with a matched cohort of early MN using Pearsons exact tests, independent t-tests, and one-way ANOVA, depending on the appropriate variable.Results81 patients were included; 27 were temporized with TPF (n = 12) or ex-fix (n = 15). 54 early MN cases defined the matched cohort. All groups had similar patient and fracture characteristics. The difference in rates of nonunion between groups was significant, with TPF, ex-fix, and early MN groups at 17, 40, and 11% respectively (p = 0.027). Early MN had lower rates of nonunion (11% vs. 40%, p = 0.017) and deep infection (13% vs. 40%, p = 0.028) compared to ex-fix.ConclusionTemporary ex-fix followed by staged MN was associated with higher rates of nonunion and deep infection. There was no difference in complication rates between TPF and early definitive MN. These data suggest that ex-fix followed by MN of tibia fractures should be avoided in favor of early definitive MN when possible. If temporization is needed, TPF may be a better option than ex-fix. Level of Evidence: IV.

Clinical Scenario: Stress fractures are one of the most common injuries in athletes. Unfortunately, they are hard to diagnose, require multiple radiology exams and follow-up which leads to more exposure to radiation and an increase in cost. Stress fractures that are mismanaged can lead to serious complications and poorer outcomes for the athlete. During the rehabilitation process, it would be beneficial to be able to monitor the healing of fractures to know when it is safe to gradually allow a patient to a return to sport because the return to activity is not usually objective and based on pain level. Clinical Question: Can infrared thermography (IRT) be a useful tool to measure the pathophysiological state of the fracture healing? The aim of this critically appraised topic is to analyze the current evidence of IRT for measuring the temperature change in fractures to provide recommendations for medical practitioners. Summary of Key Findings: For this critically appraised topic, we examined 3 articles that compared medical imaging and IRT over multiple time points during the follow-up. The 3 articles concluded that a 1 °C asymmetry in temperature followed by a return to normal (less than 0.3 °C) temperature during the healing process of fractures can be monitored using IRT. Clinical Bottom Line: Once the patient has been diagnosed with a fracture, IRT can safely be used to monitor the evolution of a fracture. When the thermogram progresses from a hot thermogram to a cold thermogram, the healing is considered good enough to return to sport. Strength of Recommendation: Grade 2 evidence exists to support IRT being used by clinicians to monitor fracture healing. Due to the limited research and novelty of the technology, the current recommendations are for following the treatment of the fracture once the initial diagnosis is made. [ABSTRACT FROM AUTHOR]

To assess the efficacy of a novel 3D biomimetic hydrogel scaffold with immunomodulatory properties in promoting fracture healing. Immunomodulatory scaffolds were used in cell experiments, osteotomy mice treatment, and single-cell transcriptomic sequencing. In vitro, fluorescence tracing examined macrophage mitochondrial transfer and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Scaffold efficacy was assessed through alkaline phosphatase (ALP), Alizarin Red S (ARS) staining, and in vivo experiments. The scaffold demonstrated excellent biocompatibility and antioxidant-immune regulation. Single-cell sequencing revealed a shift in macrophage distribution towards the M2 phenotype. In vitro experiments showed that macrophage mitochondria promoted BMSCs' osteogenic differentiation. In vivo experiments confirmed accelerated fracture healing. The GAD/Ag-pIO scaffold enhances osteogenic differentiation and fracture healing through immunomodulation and promotion of macrophage mitochondrial transfer. [ABSTRACT FROM AUTHOR]

The periosteum contains skeletal stem/progenitor cells that contribute to bone fracture healing. However, the in vivo identity of periosteal skeletal stem cells (P-SSCs) remains unclear, and membrane protein markers of P-SSCs that facilitate tissue engineering are needed. Here, we identified integral membrane protein 2A (Itm2a) enriched in SSCs using single-cell transcriptomics. Itm2a+ P-SSCs displayed clonal multipotency and self-renewal and sat at the apex of their differentiation hierarchy. Lineage-tracing experiments showed that Itm2a selectively labeled the periosteum and that Itm2a+ cells were preferentially located in the outer fibrous layer of the periosteum. The Itm2a+ cells rarely expressed CD34 or Osx, but expressed periosteal markers such as Ctsk, CD51, PDGFRA, Sca1, and Gli1. Itm2a+ P-SSCs contributed to osteoblasts, chondrocytes, and marrow stromal cells upon injury. Genetic lineage tracing using dual recombinases showed that Itm2a and Prrx1 lineage cells generated spatially separated subsets of chondrocytes and osteoblasts during fracture healing. Bone morphogenetic protein 2 (Bmp2) deficiency or ablation of Itm2a+ P-SSCs resulted in defects in fracture healing. ITM2A+ P-SSCs were also present in the human periosteum. Thus, our study identified a membrane protein marker that labels P-SSCs, providing an attractive target for drug and cellular therapy for skeletal disorders. [ABSTRACT FROM AUTHOR]

Background: Distal femoral fractures account for less than 1% of all fractures. The therapy of choice is usually surgical stabilization. Despite advances in implant development over the past few years, complication rate remains comparatively high. The aim of this study is to analyze our results with plate fixation of distal femoral fractures with a focus on complication and fracture healing rates. Methods: In this retrospective cohort study, patients (> 18 years) with distal femoral fractures treated at an urban level I trauma center between 2015 and 2022 were analyzed. Results: In total, 206 patients (167 female, 39 male) with an average age of 75 (SD 16) years were diagnosed with a fracture of the distal femur. One hundred fourteen of these patients were treated surgically by means of plate osteosynthesis. In 13 cases (11.41%), a revision procedure had to be performed. The indication for surgical revision was mechanical failure in eight cases (7.02%) and septic complication in five cases (4.39%). Periprosthetic fractures were more likely to cause complications overall (19.6% versus 4.76%) and further included all documented septic complications. The analysis of modifiable surgical factors in the context of plate osteosynthesis showed higher complication rates for cerclage in the fracture area compared with plate-only stabilizations (44.44% versus 22.22%). Conclusions: The data show an increased amount of revisions and a significantly higher number of septic complications in the treatment of periprosthetic fractures of the distal femur compared with non-periprosthetic fractures. The detected combination of plates together with cerclage was associated with higher complication rates. Level of evidence Level III retrospective comparative study. [ABSTRACT FROM AUTHOR]

Background Objective Methods Results Conclusion Although the specific relationship between the stress changes in the external fixator during tibial fracture treatment and the bone healing process remains unclear, it is believed that stress variations in the external fixator scaffold can, to a certain extent, reflect the progress of tibial healing.This study aims to propose a non‐invasive method for assessing the degree of fracture healing by monitoring the changes in stress transmission, the locations of stress‐sensitive points, and displacement in the external fixator‐tibia system during the healing process of tibial fractures.In this study, finite element models of tibial fractures at various healing stages were developed. Physiological conditions, including axial, torsional, and bending loads on the tibia, were simulated to evaluate stress and strain within the external scaffold‐tibia system under normal physiological loading conditions.The results indicate variations in the stress distribution between the external fixator and the tibia during different stages of healing. In the early phase of fracture healing, the external fixator plays a crucial role as the primary load‐bearing unit under all three loading conditions. As the fracture healing progresses, the stress on the tibia gradually increases, concentrating on the medial part of the tibia under axial and torsional loading, and at the upper and lower ends, as well as the central part of the anterior and posterior tibia during bending loading. The stress at the callus gradually increases, while micro‐movements decrease. The stress within the external bracket gradually decreases, with a tendency for the connecting rod to transfer stress towards the screws. Throughout the fracture healing process, the location of maximum stress in the external fixator remains unchanged. Under axial and torsional loading, the maximum stress is located at the intersection of the lowest screw and the bone cortex, while under bending loading, it is at the intersection of the second screw and the connecting rod.During the bone healing process, stress is transferred between the external fixation frame and the bone. As bone healing advances, the stress on the connecting rods and screws of the external fixation frame decreases, and the amplitude of stress changes diminishes. When complete and robust fusion is achieved, stress variations stabilize, and the location of maximum stress on the external fixation frame remains unchanged. The intersections of the lowest screw and the bone cortex, as well as the second screw and the connecting rod, can serve as sensitive points for monitoring the degree of bone healing. [ABSTRACT FROM AUTHOR]

In this research, the finite-element numerical software COMSOL Multiphysics is used to simulate the electric pulse rock-breaking process, and the novel numerical model takes into account the multiple fields of electrical, thermal, and mechanical physics. The electric field strength inside the rock under the action of the electric pulse is updated by the full coupling function of COMSOL (version 6.1) software, and the electric damage variable χ is used to describe the process of electric breakdown inside the rock, to simulate the formation of plasma channel in the process of electric pulse rock-breaking. The voltage change curves and plasma channel trajectories in the electric breakdown process of the model in this paper are compared with the literature to verify the accuracy of the model. The formation process of plasma channels captures the temperature and stress changes during the whole process of electric pulse rock-breaking, to reveal the mechanism of the electric pulse rock-breaking process. With the presence of conductive particles inside the rock, the particles can effectively promote the formation of plasma channels, increase the area of electrical damage, and improve rock-breaking efficiency. Before the formation of the plasma channel, the internal temperature of the rock is about 600 K, and the stress is about 10−2 MPa; when the channel is formed, the energy of the electric pulse is mainly concentrated in the plasma channel, and the temperature of the plasma channel rises to 104 K. When the maximum stress exceeds the critical stress of the rock, the rock undergoes fracture. Furthermore, an appropriate increase in the rise time of the electric pulse increases the speed and area of rock-breaking, subsequently improving the efficiency of rock fracture. The results of the numerical modeling in this paper help to better understand the mechanism of the electric pulse rock-breaking process, which is of great engineering significance for the development of new electric pulse rock-breaking technology in the realm of geotechnical engineering. [ABSTRACT FROM AUTHOR]

Magnesium as a biodegradable material offers promising results in recent studies of different maxillo-facial fracture models. To overcome adverse effects caused by the fast corrosion of pure magnesium in fluid surroundings, various alloys, and surface modifications are tested in animal models. In specified cases, magnesium screws already appeared for clinical use in maxillofacial surgery. The present study aims to compare the bone healing outcome in a non-load-bearing fracture scenario of the forehead in sheep when fixed with standard-sized WE43 magnesium fixation plates and screws with plasma electrolytic oxidation (PEO) surface modification in contrast to titanium osteosynthesis. Surgery was performed on 24 merino mix sheep. The plates and screws were explanted en-bloc with the surrounding tissue after four and twelve weeks. The outcome of bone healing was investigated with micro-computed tomography, histological, immunohistological, and fluorescence analysis. There was no significant difference between groups concerning the bone volume, bone volume/ total volume, and newly formed bone in volumetric and histological analysis at both times of investigation. The fluorescence analysis revealed a significantly lower signal in the magnesium group after one week, although there was no difference in the number of osteoclasts per mm2. The magnesium group had significantly fewer vessels per mm2 in the healing tissue. In conclusion, the non-inferiority of WE43-based magnesium implants with PEO surface modification was verified concerning fracture healing under non-load-bearing conditions in a defect model. Titanium implants, the current gold standard of fracture fixation, can lead to adverse effects linked to the implant material and often require surgical removal. Therefore, degradable metals like the magnesium alloy WE43 with plasma electrolytic oxidation (PEO) surface modification gained interest. Yet, miniplates of this alloy with PEO surface modification have not been examined in a fracture defect model of the facial skeleton in a large animal model. This study shows, for the first time, the non-inferiority of magnesium miniplates compared to titanium miniplates. In radiological and histological analysis, bone healing was undisturbed. Magnesium miniplates can reduce the number of interventions for implant removal, thus reducing the risk for the patient and minimizing the costs. [Display omitted] [ABSTRACT FROM AUTHOR]

The immune system plays an important role in fracture healing, by modulating the pro-inflammatory and anti-inflammatory responses occurring instantly upon injury. An imbalance in these responses can lead to adverse outcomes, such as non-union of fractures. Implants are used to support and stabilize complex fractures. Biodegradable metallic implants offer the potential to avoid a second surgery for implant removal, unlike non-degradable implants. However, considering our dynamic immune system it is important to conduct in-depth studies on the immune response to these implants in living systems. In this study, we investigated the immune response to Mg and Mg-10Gd in vivo in a rat femur fracture model with external fixation. In vivo imaging using liposomal formulations was used to monitor the fluorescence-related inflammation over time. We combine ex vivo methods with our in vivo study to evaluate and understand the systemic and local effects of the implants on the immune response. We observed no significant local or systemic effects in the Mg-10Gd implanted group compared to the SHAM and Mg implanted groups over time. Our findings suggest that Mg-10Gd is a more compatible implant material than Mg, with no adverse effects observed in the early phase of fracture healing during our 4-week study. Degradable metallic implants in form of Mg and Mg-10Gd intramedullary pins were assessed in a rat femur fracture model, alongside a non-implanted SHAM group with special respect to the potential to induce an inflammatory response. This pre-clinical study combines innovative non-invasive in vivo imaging techniques associated with multimodal, ex vivo cellular and molecular analytics. The study contributes to the development and evaluation of degradable biometals and their clinical application potential. The study results indicate that Mg-10Gd did not exhibit any significant harmful effects compared to the SHAM and Mg groups. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Patients undergoing hemodialysis are at an elevated risk of fractures; however, substantial evidence for osteoporosis treatment in this population is lacking. We explored the efficacy of denosumab, an anti-IgG2 antibody that targets the receptor activator of nuclear factor-kappa B ligand, in reducing fracture incidence and all-cause mortality in patients undergoing hemodialysis. Methods: This retrospective cohort study—conducted from December 2013 to December 2022—evaluated the effects of denosumab on fracture incidence and all-cause mortality. Patients who initiated denosumab treatment during the study period were defined as the denosumab group, while those without a history of denosumab administration were defined as the non-denosumab group. Kaplan–Meier curves and log-rank tests were used to assess survival and fracture/mortality risks, respectively. Cox proportional hazards models were used to analyze both fractures and all-cause mortality. Results: Among 214 patients undergoing hemodialysis, 52 (24.3%) received denosumab. The median age was 73.0 ± 11.5 years, with 92 (43.0%) females, and the median dialysis duration was 59 months (interquartile range, 6–126). During the study, thirty-seven non-denosumab-treated patients had fractures compared to eight in the denosumab group. No significant differences were observed in the unadjusted model (HR, 0.53; 95% confidence interval (CI), 0.24–1.14). Adjusting for competing mortality and clinical factors, the HR remained at 0.64 (95% CI, 0.27–1.51). Regarding all-cause mortality, we found a statistically significant difference in the unadjusted model (HR, 0.61 [95% CI, 0.38–0.98]). A significant reduction in mortality was observed in the adjusted model (HR, 0.46 [95% CI, 0.26–0.80]). Notably, the denosumab group showed a significant decrease in mortality, particularly in cardiovascular disease-related cases (HR, 0.33 [95% CI, 0.14–0.78]). Conclusions: Denosumab may reduce all-cause mortality in patients undergoing hemodialysis, particularly in those with cardiovascular complications. This finding offers a promising direction for osteoporosis treatment in patients undergoing hemodialysis. [ABSTRACT FROM AUTHOR]

Background: Vertebral and pelvic fractures are associated with a significant burden of negative health and psychosocial outcomes. The number of vertebral and pelvic fractures is increasing in an aging society. Vertebral and pelvic fractures are increasingly significant injuries for individuals and society. However, few epidemiological studies have examined the clinical course of vertebral and pelvic fractures. This is the protocol for a study that observes patients who have been admitted to the hospital with an incident vertebral or pelvic fracture for a period of 12 months. Methods: The observational cohort study is conducted at three study sites in Germany. Patients affected by vertebral or pelvic fractures are recruited within the first few days of hospital admission. Data collection takes place at four-time points: baseline, before discharge, after 4 months, and after 12 months after admission to the hospital. Particular emphasis is laid on the assessment of the fall mechanisms, physical function, physical activity, life space, mobility, treatment approach, and quality of life. The hospital stay involves the collection of biomaterials (blood and urine). Discussion: The study aims to enhance understanding of the clinical progression and outcomes in patients with fractures in the vertebrae or pelvis. [ABSTRACT FROM AUTHOR]

BACKGROUND: The treatment of distal tibial comminuted fractures with soft tissue injury has always been challenging. The new retrograde tibial nailing and supercutaneous locking plate are important treatment methods, but their strain and stress shielding at the fracture end during different periods of fracture healing and different load conditions have not been reported. OBJECTIVE: To explore the biomechanical stability of retrograde tibial nailing and supercutaneous locking plate in different periods of fracture healing by finite element analysis to offer a scientific foundation for clinical application and rehabilitation exercise. METHODS: The finite element model of distal tibial comminuted fracture was established by utilizing the CT data of the tibia from a 40-year-old healthy male. Retrograde tibial nailing, supercutaneous locking plate, and callus models were assembled in accordance with the principle of fracture fixation. The finite element analysis was performed using ANSYS software to compare the displacement of the fracture end, the stress shielding of the tibia, the stress of the callus, and the stress distribution of the tibia and the fixation device during different periods of fracture healing. RESULTS AND CONCLUSION: (1) The relative displacement of the tibial fracture decreased gradually with the healing of the fracture, and the displacement decreased significantly after 3 months. At 0 and 1 months after operation, the vertical displacement and total displacement of the supercutaneous locking plate group were higher than those in the retrograde intramedullary nail group. The Z-axis displacement (horizontal medial and lateral displacement) of the two fixation methods was more obvious than the X-axis and Y-axis, and the Z-axis displacement of supercutaneous locking plate group was the most obvious. The maximum Z-axis displacement of the two fixation methods was located on the outside of the tibia, and the minimum displacement was located on the inside of the tibia. (2) The stress shielding rate at different periods of fracture healing gradually decreased with time. The stress shielding rate of the retrograde intramedullary nail was higher than that of the supercutaneous locking plate at different stages of fracture healing. After 3 months, the stress shielding rate of the supercutaneous locking plate was reduced to about 4%, and the stress shielding rate of the retrograde intramedullary nail was reduced to about 40%. (3) The stress of the stress concentration site of the callus in the two fixation methods increased with the increase of the load, and the stress of the callus in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group. The maximum stress distribution of the callus was approximately equally distributed among the two modes of fixation, both in the lateral portion of the tibia. (4) As the fracture healed, the maximum stress of the tibia in the two groups decreased gradually, and the stress in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group. The average stress of the maximum stress area of the tibia in the supercutaneous locking plate group under 1 500 N load was 285 MPa, while that in the retrograde intramedullary nail group was 26 MPa. (5) As the fracture healed, the stress of the fixation device in the two groups decreased gradually, and the stress in the supercutaneous locking plate group was significantly higher than that in the retrograde intramedullary nail group. After 3 months, the stress of the two fixation devices decreased significantly. (6) It is indicated that in the early stage of fracture healing, the strain on the fracture end in the retrograde intramedullary nail group is small, and the maximum stress of the tibia is moderate, allowing early loaded. The fractured ends in the supercutaneous locking plate group had too large strain and too large maximum stress of the tibia, which needed to be partially loaded under protection and could not be fully loaded. In the middle and late stages of fracture healing, the tibial retrograde intramedullary nail and the supercutaneous locking plate could be completely loaded, and the stress shielding rate of the supercutaneous locking plate was significantly lower than the tibial retrograde intramedullary nail. [ABSTRACT FROM AUTHOR]

Musculoskeletal changes occur with gender-affirming hormonal therapy (GAHT) and gender-affirming surgery (GAS) used in the care of transgender adolescents and adults. Survey results have shown that orthopaedic surgeons desire to care for transgender individuals but express concern over a knowledge deficit. This article reviews the physiology and pathophysiology that may occur with GAHT and GAS. Transgender women have lower bone mineral density (BMD) prior to GAHT than cisgender men. Limited fracture data would suggest that transgender women >50 years of age have fracture rates similar to those of cisgender women. Transgender men have normal BMD prior to GAHT and are not at an increased risk for fracture compared with cisgender women. The use of puberty-blocking medications in the care of transgender youth does result in a decline in BMD, which returns to baseline with GAHT, but the effect of delaying puberty on maximal BMD and the lifetime fracture risk are unknown. At present, dual x-ray absorptiometry (DXA) is used to measure BMD and assess fracture risk. Attention should be paid to using the appropriate reference group in the interpretation of DXA for transgender individuals. Promote musculoskeletal health by ensuring appropriate calcium, vitamin D, weight-bearing activity, and a healthy lifestyle. Adherence to GAHT needs to be encouraged to avoid bone loss. Data with regard to therapy for osteoporosis in transgender patients have been lacking, but, at present, use of available therapies is expected to be effective. Information with regard to differences in other musculoskeletal health issues such as joint injuries has been lacking in transgender individuals. [ABSTRACT FROM AUTHOR]

Background: Distal tibial fractures represent common lower limb injuries, frequently accompanied by significant soft tissue damage. The optimal surgical approach for managing these fractures remains a topic of considerable debate. The aim of this study was to perform a comparative analysis of the outcomes associated with retrograde intramedullary tibial nails (RTN) and minimally invasive plate osteosynthesis (MIPO) in the context of treating extra-articular distal tibial fractures. Methods: A retrospective review was conducted on a cohort of 48 patients who sustained extra-articular distal tibial fractures between December 2019 and December 2021. Patients underwent either RTN or MIPO procedures. Various parameters, including operative duration, intraoperative fluoroscopy exposure, time to union, duration until full weight-bearing, American Orthopedic Foot and Ankle Society (AOFAS) scores, and complications, were recorded and compared between the two treatment groups. Results: No statistically significant differences were observed in operative duration, time to union, angulation of the distal tibial coronal plane, or AOFAS scores between the RTN and MIPO groups. However, the RTN group had a higher average number of intraoperative fluoroscopy images (8.2 ± 2.3) compared to the MIPO group (4.1 ± 2.0). The RTN group demonstrated shorter average hospital stays (7.1 ± 1.4 days) and a quicker return to full weight-bearing (9.9 ± 1.3 weeks), which were significantly superior to the MIPO group (9.0 ± 2.0 days and 11.5 ± 1.5 weeks, respectively). In terms of complications, the RTN group had one case of superficial infection, whereas the MIPO group exhibited two cases of delayed union and nonunion, two occurrences of deep infection, and an additional three cases of superficial infection. Conclusions: Both RTN and MIPO are effective treatment options for extra-articular distal tibial fractures. However, RTN may offer superior outcomes in terms of decreased inpatient needs, faster return to full weight-bearing capacity, and a lower rate of complications. [ABSTRACT FROM AUTHOR]

Lower extremity fractures pose challenges due to prolonged healing times and limited assessment methods. Integrating wearable sensors with machine learning can help overcome these challenges by providing objective assessment and predicting fracture healing. In this retrospective study, data from a gait monitoring insole on 25 patients with closed lower extremity fractures were analyzed. Continuous underfoot loading data were processed to isolate steps, extract metrics, and feed them into three white-box machine learning models. Decision tree and Lasso regression aided feature selection, while a logistic regression classifier predicted days until fracture healing within a 30-day range. Evaluations via 10-fold cross-validation and leave-one-out validation yielded stable metrics, with the model achieving a mean accuracy, precision, recall, and F1-score of approximately 76%. Feature selection revealed the importance of underfoot loading distribution patterns, particularly on the medial surface. Our research facilitates data-driven decisions, enabling early complication detection, potentially shortening recovery times, and offering accurate rehabilitation timeline predictions. [ABSTRACT FROM AUTHOR]

Background: The surgical treatment of bony non-unions is traditionally performed with additional bone grafts when atrophic and/or stronger implants when hypertrophic. In the case of the clavicle shaft, however, in our experience, a more controversial method where no additional bone graft is needed leads to equally good consolidation rates, independent of the non-union morphology. This method requires the meticulous anatomical reconstruction of the initial fracture and fixation according to the AO principle of relative stability. Methods: A retrospective review following the STROBE guidelines was performed on a consecutive cohort of all patients who received surgical treatment of a midshaft clavicle non-union at the Medical Center of the University of Freiburg between January 2003 and December 2023. Patients were identified using a retrospective systematical query in the Hospital Information System (HIS) using the International Statistical Classification of Diseases and Related Health Problems Version 10 (ICD-10) codes of the German Diagnosis Related Groups (G-DRG). Two groups were formed to compare the consolidation rates of patients who received additional bone grafting from the iliac crest with those of patients who did not. A 3.5 mm reconstruction LCP plate was used in all patients. Consolidation rates were evaluated using follow-up radiographs and outcomes after material removal with a mean follow-up of 31.5 ± 44.3 months (range 0–196). Results: Final data included 50 patients, predominantly male (29:21); age: 46.0 ± 13.0 years, BMI 26.1 ± 3.7. Autologous bone grafts from the iliac crest were used in 38.0% (n = 19), while no bone addition was used in 62.0% (n = 30). Six patients were lost to follow-up. Radiological consolidation was documented after a mean of 15.1 ± 8.0 months for the remaining 44 patients. Consolidation rates were 94.4% (n = 17) in patients for whom additional bone grafting was used and 96.2% (n = 25) in patients for whom no graft was used. There was no relevant difference in the percentage of atrophic or hypertrophic non-unions between both groups (p = 0.2425). Differences between groups in the rate of consolidation were not significant (p = 0.7890). The complication rate was low, with 4.5% (n = 2). Conclusions: Independent of the non-union morphology, non-unions of the clavicle midshaft can be treated successfully with 3.5 mm locking reconstruction plates without the use of additional bone grafting in most cases. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion Rapid and effective reduction is difficult for minimally invasive plate osteosynthesis (MIPO) surgery. This study aims to introduce a bidirectional rapid reductor (BRR) designed to assist in the reduction during MIPO surgery for proximal humeral fractures (PHFs).This retrospective study was conducted between June 2021 and February 2022 in the Third Hospital of Hebei Medical University, involving patients diagnosed with PHFs. A detailed technical approach of BRR in MIPO surgery was described, and the patients' outcomes based on postoperative radiographic results including x‐ray postoperative follow‐up, and clinical outcome parameters including visual analogue scale (VAS) and constant‐Murley score at last follow‐up were reported.A total of 12 patients were included in this study, comprising three males and nine females, with an average age of 67.58 years. The mean operative time was 70.92 min (range 63–80 min). The mean blood loss was 102.27 mL (range 50–300 mL). The mean VAS and constant‐Murley scores at final follow‐up were 0.33 and 88, respectively. All patients had their fractures healed without secondary displacement at last follow‐up. One patient experienced shoulder stiffness post‐operation. There were no adverse events or complications following the use of this technique, such as acromion fracture, nerve or blood vessel injury.The BRR can assist MIPO for good reduction of PHFs. However, the efficacy should be validated with a large‐sample randomized controlled trial and longer follow‐up. [ABSTRACT FROM AUTHOR]

Background: The Internal Fixator (INFIX) is a popular method, known for its minimal invasiveness and short operation time, for treating anterior pelvic ring fractures. Studies have shown that postoperative complications may occur, including anterolateral femoral cutaneous nerve injury, the femoral nerve paralysis, and delayed fracture healing. These complications are believed to be related to surgical stimulation, an excessively long lateral end of the connecting rod, a small distance between the screw and bone surface, insufficient pre-bending of the connecting rod, and difficulties in fracture reduction. Case presentation: We report two unique cases of lower abdominal pseudocyst complicated with suspected infection after INFIX treatment of pelvic fractures at our trauma center. Following surgical removal of the internal fixation, resolution of the cysts was observed in both patients, and subsequent postoperative follow-up revealed the absence of any residual sequelae. These cases have not been reported in previous literature reviews. Discussion: The lower abdominal cysts, potentially arising from the dead space created during intraoperative placement of the INFIX rod, may increase infection risk. The etiology remains uncertain, despite the presence of abnormal inflammation markers in both cases, and staphylococcus aureus found in one. These cysts were confined to the lower abdomen, not involving the internal fixation, and hence, only the INFIX was removed. Postoperative oral cefazolin treatment was successful, with resolved pseudocysts and no subsequent discomfort. Conclusion: We report two unprecedented cases of post-INFIX abdominal cysts, with a suspected link to intraoperative dead space. Despite uncertain etiology, successful management involved INFIX removal and oral cefixime therapy. These findings necessitate further exploration into the causes and management of such complications. [ABSTRACT FROM AUTHOR]

Background: The reconstruction of segmental long bone defects remains one of 'The holy grails of orthopaedics'. The optimal treatment of which remains a topic of great debate. This study aimed to evaluate the outcomes following the management of critical-sized bone defects using a classification-based treatment algorithm. Methods: A retrospective review of all patients undergoing treatment for segmental diaphyseal defects of long bones at a tertiary-level limb reconstruction unit between January 2016 and December 2021, was performed. The management of the bone defect was standardised as per the classification by Ferreira and Tanwar (2020). Results: A total of 96 patients (mean age 39.8, SD 15.2) with a minimum six months follow-up were included. Most bone defects were the result of open fractures (75/96) with 67% associated with Gustilo-Anderson IIIB injuries. There was a statistical difference in the likelihood of union between treatment strategies with more than 90% of cases undergoing acute shortening and bone transport achieving union and only 72% of cases undergoing the induced membrane technique consolidating (p = 0.049). Of those defects that consolidated, there was no difference in the time to bone union between strategies (p = 0.308) with an overall median time to union 8.33 months (95% CI 7.4 – 9.2 months). The induced membrane technique was associated with a 40% risk of sepsis. Conclusion: This study reported the outcomes of a standardised approach to the management of critical-sized bone defects. Whilst overall results were supportive of this approach, the outcomes associated with the induced membrane technique require further refinement of its indications in the management of critical-sized bone defects. Level of evidence: 4. [ABSTRACT FROM AUTHOR]

Purpose: To assess the use of bone marrow aspirate (BM) and bone marrow aspirate concentrate (BMAC) in the treatment of long-bone nonunion and to understand mechanism of action. Methods: A systematic review of PubMed and EBSCOHost was completed to identify studies that investigated the use of BM or BMAC for the diagnosis of delayed union and/or nonunion of long-bone fractures. Studies of isolated bone marrow-mesenchymal stem cells (BM-MSCs) and use in non-long-bone fractures were excluded. Statistical analysis was confounded by heterogeneous fracture fixation methods, treatment history, and scaffold use. Results: Our initial search yielded 430 publications, which was screened down to 25 studies. Successful treatment in aseptic nonunion was reported at 79–100% (BM) and 50–100% (BMAC). Septic nonunion rates were slightly better at 73–100% (BM) and 83.3–100% (BMAC). 18/24 studies report union rates > 80%. One study reports successful treatment of septic nonunion with BMAC and no antibiotics. A separate study reported a significant reduction in autograft reinfection rate when combined with BMAC (P = 0.009). Major adverse events include two deep infections at injection site and one case of heterotopic ossification. Most studies note transient mild donor site discomfort and potential injection site discomfort attributed to needle size. Conclusion: The current literature pertaining to use of BM/BMAC for nonunion is extremely heterogeneous in terms of patient population and concomitant treatment modalities. While results are promising for use of BM/BMAC with other gold standard treatment methodologies, the literature requires additional Level I data to clarify the impact of role BM/BMAC in treating nonunion when used alone and in combination with other modalities. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare reoperation rate and clinical outcomes between revision open reduction and internal fixation and hip arthroplasty following failed subtrochanteric fracture fixation. Methods: A retrospective review was conducted of patients > 50 years old treated for failed fixation of subtrochanteric fractures with revision ORIF or hip arthroplasty from 2003 to 2023. Primary outcomes included rate of fracture union and reoperations after initial salvage therapy. Secondary outcomes included complications (infection, dislocation, bursitis, implant prominence, implant failure, nonunion), pain, and gait-aid requirements by final follow-up. Results: Forty-four patients were identified: 34 treated with revision ORIF and 10 with hip arthroplasty. The arthroplasty cohort was older (75.4 vs. 66.0 years, p = 0.016) but did not differ from the ORIF cohort in sex, type of initial fixation, or reason for fixation failure. Patients treated with revision ORIF and patients treated with arthroplasty had similar rates of fracture union (85.3% vs. 80.0%, p = 0.772) and reoperation (35.3% vs. 30.0%, p = 0.710). There was no significant difference in rate of additional complications not requiring reoperation (0.0% vs. 40.0%, p = 0.071). The arthroplasty cohort achieved full weightbearing in significantly shorter time than the revision ORIF cohort (3.8 vs. 6.8 weeks, p = 0.005). Conclusion: Both revision ORIF and hip arthroplasty are acceptable options for salvage of failed subtrochanteric fracture fixation in patients greater than 50 years old, but patients should be counseled that although the rate of fracture union is high whether revision ORIF or hip arthroplasty is selected, the rate of reoperation can exceed 1-in-4 patients. Level of Evidence: Level III, Retrospective Comparative Study. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this research is to demonstrate echinacoside promotes osteogenesis and angiogenesis and inhibits osteoclast formation. Methods: We conducted a cell experiment in vitro to study how echinacoside affects angiogenesis, osteogenesis and osteoclast formation. We used polymerase chain reaction and Western blotting to detect the expression levels of proteins and genes related to angiogenesis, osteogenesis and osteoclast formation. We established a bone fracture model with rats to test angiogenesis, osteogenesis and osteoclast formation of echinacoside. We labelled osteogenic markers, blood vessels and osteoclastic markers in fracture sections of rats. Results: The in vitro cell experiments showed echinacoside improved the osteogenic activity of mouse embryo osteoblast precursor cells and promoted the migration and tube formation of human umbilical vein endothelial cells. In addition, it inhibited differentiation of mouse leukaemia cells of monocyte macrophage. Echinacoside increased the expression of related proteins and genes and improved angiogenesis and osteogenesis while inhibiting osteoclast formation by repressing the expression of related proteins and genes. From in vivo experiments, the results of IHC and HE experiments demonstrated echinacoside significantly decreased the content of MMP‐9 and improved the content of VEGF and OCN. The fluorescence immunoassay showed echinacoside promoted the activities of RUNX2 and VEGF and inhibited CTSK. Echinacoside reduced the content of TNF‐α, IL‐1β and IL‐6, thus demonstrating its anti‐inflammatory activity. Conclusion: Echinacoside improved angiogenesis and osteogenesis and inhibited osteoclast formation to promote fracture healing. [ABSTRACT FROM AUTHOR]

Background/Aim. The number of pelvic traumas is increasing globally, mostly due to car accidents but also due to an increasing number of sports and recreational traumas. Tile C-type unstable pelvic trauma (TCUPT) is a kind of high-energy trauma that occurs during traffic accidents or accidents when falling from big heights. The aim of our study was to explore the application of the internal fixation (INFIX) system for the anterior pelvic ring (APR) with simultaneous application of sacroiliac screw (SS) INFIX of the posterior pelvic ring (PPR) in TCUPT. Methods. The subjects (89 of them in total) were recruited among patients with TCUPT from December 2020 to December 2023. A retrospective analysis of the subjects' data was performed, after which the subjects were divided into two groups based on different therapeutic regimens applied: group A (INFIX system for the APR + SS INFIX of the PPR, n = 46) and group B (external fixator for the APR + SS INFIX of the PPR, n = 43). Results. In comparison with group B, group A had a shorter period before the commencement of the first activity after surgery, shorter fracture healing time and joint function recovery time, as well as length of hospital stay (t = 6.623, 4.796, 7.992, and 5.227, respectively, p < 0.05). The surgery duration and bleeding volume showed no significant differences between the two groups (t = 1.433, 1.123, respectively, p > 0.05). The fracture reduction outcomes were better in group A than in group B (Z = 2.058, p < 0.05). The incidence rate of complications was lower in group A than in group B (2.17% vs. 18.60%) (2 = 4.917, p < 0.05). Conclusion. For patients with TCUPT, the INFIX system for the APR with simultaneous application of SS INFIX of the PPR achieves good fracture reduction outcomes. [ABSTRACT FROM AUTHOR]

Objective: Clinical concerns exist regarding the quality of bony consolidation in the context of the induced membrane technique. This study evaluates the clinical process of bone grafting in the second stage of induced membrane bone union in patients with tibial bone defects to infer the possibility of non‐union and establish a reliable and effective evaluation method combined with computed tomography (CT) to assess fracture healing. Methods: Patients with tibial bone defects who underwent the induced membrane technique at our hospital between February 2017 and February 2020 were retrospectively analyzed. The Hounsfield unit (HU) values of the patients were evaluated at different times during the second stage of bone grafting. Bone healing at the boundary value of the 120 HU output threshold (−1024 HU–3071 HU) was directionally selected, and the changes in the growth volume of union (new bone volume [selected according to HU value]/bone defect volume) were compared with analyzing individual class bone union. Method 1 involved X‐rays revealing that at least three of the four cortices were continuous and at least 2 mm thick, with the patient being pain free. For Method 2, new bone volume (selected according to HU value/bone defect volume) at the stage was compared with analyzing individual class healing. Receiver operating characteristic curve analysis was used for Methods 1 and 2. Results: A total of 42 patients with a segmental bone defect with a mean age of 40.5 years (40.5 ± 8.3 years) were included. The relationship between bone graft volume and time variation was analyzed by single factor repeated variable analysis (F = 6.477, p = 0.016). Further, curve regression analysis showed that the change in bone graft volume over time presented a logarithmic curve pattern (Y = 0.563 + 0.086 × ln(X), Ra2 = 0.608, p = 0.041). ROC curve analysis showed that Method 2 is superior to Method 1 (AUC: 86.3% vs. 68.3%, p < 0.05). Conclusion: The induced membrane technique could be used to treat traumatic long bone defects, with fewer complications and a higher healing rate. The proposed imaging grading of HU (new bone volume/bone defect volume) can be used as a reference for the quality of bony consolidation with the induced membrane technique. [ABSTRACT FROM AUTHOR]

Fractures and bone nonunion commonly require surgical intervention. Serious outcomes of non‐healing in the late stages of fracture place a significant financial burden on society and families. Bone nonunion occurs when a fracture stops healing, for many reasons, and leads to a variety of bad outcomes. Numerous factors, including biomechanics and immunology, are involved in the complicated mechanisms of bone nonunion. The immune‐inflammatory response plays a significant part in the emergence of bone nonunion, and the occurrence, control, and remission of inflammation in the bone healing process have a significant influence on the ultimate success of bone tissue repair. In the bone microenvironment, immune cells and associated cytokines control bone repair, which is significantly influenced by macrophages, T cells, and fibroblast growth factor. To limit acute inflammation and balance osteogenesis and osteoblastogenesis for tissue repair and regeneration, immune cells and various cytokines in the local microenvironment must be precisely regulated. As a bad complication of late‐stage fractures, bone nonunion has a significant effect on patients' quality of life and socioeconomic development. Therefore, in‐depth research on its pathogenesis and treatment methods has important clinical value. To provide more precise, focused therapeutic options for the treatment of bone nonunion, we discuss the regulatory roles of the key immune cells engaged in bone healing within the microenvironment during bone healing and their effect on osteogenesis. [ABSTRACT FROM AUTHOR]

The prognosis of fracture is directly related to several factors. Due to the limitations of existing treatment strategies, there are still many fractures with poor healing. Bone marrow mesenchymal stem cells (BMSCs) have the potential to differentiate into osteoblasts and chondrocytes. Therefore, BMSC transplantation is promised as an effective method for treating bone fractures. We aim to explore whether silently expressing sclerostin gene (SOST) can promote bone formation through the SOST/Wnt/β-catenin signal pathway. We isolated rat BMSCs and the target gene (SOST shRNA) was transduced into them for osteogenic induction. The results showed that SOST significantly inhibited the proliferation and osteogenic differentiation of BMSCs during osteogenic induction, whereas silently expressing SOST not only increased the number of surviving BMSCs but also promoted the expression of osteogenesis-related proteins RUNX2, osteoprotegerin, Collagen I (COL-I), and bone morphogenetic protein-2 during osteogenic induction. The results of imaging examination in rats show that downregulating the expression of SOST can promote the formation of bony callus and the transformation of cartilage tissue into normal bone tissue, and then accelerate the healing of osteoporotic fracture. In addition, we also found that SOST silencing can activate the Wnt/β-catenin pathway to achieve these effects. In conclusion, SOST silencing can promote the proliferation and osteogenic differentiation of BMSCs in situ, and therefore may enhance the therapeutic efficiency of BMSC transplantation in OPF. [ABSTRACT FROM AUTHOR]

We applied physics-informed neural networks to solve the constitutive relations for nonlinear, path-dependent material behavior. As a result, the trained network not only satisfies all thermodynamic constraints but also instantly provides information about the current material state (i.e., free energy, stress, and the evolution of internal variables) under any given loading scenario without requiring initial data. One advantage of this work is that it bypasses the repetitive Newton iterations needed to solve nonlinear equations in complex material models. Furthermore, after training, the proposed approach requires significantly less effort in terms of implementation and computing time compared to the traditional methods. The trained model can be directly used in any finite element package (or other numerical methods) as a user-defined material model. We tested this methodology on rate-independent processes such as the classical von Mises plasticity model with a nonlinear hardening law, as well as local damage models for interface cracking behavior with a nonlinear softening law. In order to demonstrate the applicability of the methodology in handling complex path dependency in a three-dimensional (3D) scenario, we tested the approach using the equations governing a damage model for a three-dimensional interface model. Such models are frequently employed for intergranular fracture at grain boundaries. However, challenges remain in the proper definition of collocation points and in integrating several non-equality constraints that become active or non-active simultaneously. As long as we are in the training regime, we have observed a perfect agreement between the results obtained through the proposed methodology and those obtained using the classical approach. Finally, we compare this new approach against available standard methods and discuss the potential and remaining challenges for future developments. [ABSTRACT FROM AUTHOR]

This retrospective study investigated the clinical and radiographic outcomes following temporary transpedicular posterior instrumentation between two cohorts of patients with thoracolumbar fractures (TLF) who underwent selective or bi-segments intervertebral articular process fusion. Patients with TLF who underwent the temporary posterior fixation with selective fusion (Group SF), or bi-segments fusion (Group BF) were studied. Superior intervertebral articular process and interlaminar fusion were performed in Group SF, whereas in Group BF, the patients underwent bi-segments fusion in both superior and inferior articular processes, as well as interlaminar fusion. We measured the distal and proximal intervertebral mobility, regional kyphotic angle, and vertebral height before and after surgery in both groups. Greenough Low-Back Outcome Score was used to assess the clinical outcomes. Sixty-five patients with TLF from T12 to L2 fractures were enrolled in the study period: 33 patients in the Group SF and 32 patients in the Group BF. All the patients experienced fracture healing (mean follow-up time: 19.7 months). The mean postoperative functional outcomes were 65.0 ± 2.0 points for the Low-Back Outcome Score in the Group SF and 65.2 ± 1.8 for the Group BF. A progressive regional kyphotic angle was observed with time regardless of fusion but was not significantly different between the two groups. There was a statistical difference between unfused inferior proximal adjacent and inferior distal adjacent segment regardless of fracture segments. The strategy of selective fusion is reported to be useful for the treatment of patients with TLF. The motion in the un-fused and adjacent segment could be better regained after instrumentation removal in the selective fusion group. Level 3. [ABSTRACT FROM AUTHOR]

Characterizing the fluid-driven fracture-tip advancing process presents a significant challenge due to the difficulty of replicating real-world conditions in laboratory experiments and the lack of precise field measurements. However, recent advances in low-frequency distributed acoustic sensing (LF-DAS) technology offer new opportunities to investigate the dynamics of propagating hydraulic fractures. In this study, we propose an iterative inversion method to characterize fracture-tip advancing behaviors using LF-DAS data. A forward geomechanical model is developed using the three-dimensional displacement discontinuity method, and the optimization is realized by a conjugate gradient method. The performance of the inversion algorithm is demonstrated using a synthetic case, in which the fracture half-length evolution and propagation velocity match well with the reference solutions. In addition, the averaged fracture cross-section area, fracture volume, and fracturing fluid efficiency can also be estimated, showing good agreements with true values of the synthetic case under reasonable assumptions. Then, a field case with a single-cluster hydraulic fracturing treatment from the Hydraulic Fracturing Test Site 2 project (HFTS-2) is studied. Our analysis of the inversion results reveals that the fracture propagates intermittently, as evidenced by the fracture half-length evolution. This unique field evidence can guide modeling efforts to incorporate this important physical behavior into fracture models, and the secondary information gathered from the study, including fracture cross-section area and volume, can help evaluate and optimize fracturing efficiency. Highlights: Low-frequency distributed acoustic sensing provides a unique dataset to characterize the fracture propagation process. A gradient-based inversion algorithm is developed and validated using a synthetic case to estimate the fracture tip advancing process. In the presented field case, fracture propagates continuously in the beginning, followed by an intermittent advancement pattern [ABSTRACT FROM AUTHOR]

In large animal studies, the mechanical reintegration of the bone fragments is measured using postmortem physical testing, but these assessments can only be performed once, after sacrifice. Image‐based virtual mechanical testing is an attractive alternative because it could be used to monitor healing longitudinally. However, the procedures and software required to perform finite element analysis (FEA) on subject‐specific models for virtual mechanical testing can be time consuming and costly. Accordingly, the goal of this study was to determine whether a simpler image‐based geometric measure—the torsion constant, sometimes known as polar moment of inertia—can be reliably used as a surrogate measure of bone healing in large animals. To achieve this, postmortem biomechanical testing and microCT scans were analyzed for a total of 33 operated and 20 intact ovine tibiae. An image‐processing procedure to compute the attenuation‐weighted torsion constant from the microCT scans was developed in MATLAB and this code has been made freely available. Linear regression analysis was performed between the postmortem biomechanical data, the results of virtual mechanical testing using FEA, and the torsion constants measured from the scans. The results showed that virtual mechanical testing is the most reliable surrogate measure of postmortem torsional rigidity, having strong correlations and high absolute agreement. However, when FEA is not practical, the torsion constant is a viable alternative surrogate measure that is moderately correlated with postmortem torsional rigidity and can be readily calculated. [ABSTRACT FROM AUTHOR]

Measuring the healing status of a bone fracture is important to determine the clinical care a patient receives. Implantable devices can directly and continuously assess the healing status of fracture fixation constructs, while subject‐specific virtual biomechanical tests can noninvasively determine callus structural integrity at single time points. Despite their potential for objectification, both methods are not yet integrated into clinical practice with further evidence of their benefits required. This study correlated continuous data from an implantable sensor assessing healing status through implant load monitoring with computer tomography (CT) based longitudinal finite element (FE) simulations in a large animal model. Eight sheep were part of a previous preclinical study utilizing a tibial osteotomy model and equipped with such a sensor. Sensor signal was collected over several months, and CT scans were acquired at six interim time points. For each scan, two FE analyses were performed: a virtual torsional rigidity test of the bone and a model of the bone‐implant construct with the sensor. The longitudinal simulation results were compared to the sensor data at corresponding time points and a cohort‐specific empirical healing rule was employed. Healing status predicted by both in silico simulations correlated significantly with the sensor data at corresponding time points and correctly identified a delayed and a nonunion in the cohort. The methodology is readily translatable with the potential to be applied to further preclinical or clinical cohorts to find generalizable healing criteria. Virtual mechanical tests can objectively measure fracture healing progressing using longitudinal CT scans. [ABSTRACT FROM AUTHOR]

Summary: Antiresorptive medications do not negatively affect fracture healing in humans. Teriparatide may decrease time to fracture healing. Romosozumab has not shown a beneficial effect on human fracture healing. Background: Fracture healing is a complex process. Uncertainty exists over the influence of osteoporosis and the medications used to treat it on fracture healing. Methods: Narrative review authored by the members of the Fracture Working Group of the Committee of Scientific Advisors of the International Osteoporosis Foundation (IOF), on behalf of the IOF and the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT). Results: Fracture healing is a multistep process. Most fractures heal through a combination of intramembranous and endochondral ossification. Radiographic imaging is important for evaluating fracture healing and for detecting delayed or non-union. The presence of callus formation, bridging trabeculae, and a decrease in the size of the fracture line over time are indicative of healing. Imaging must be combined with clinical parameters and patient-reported outcomes. Animal data support a negative effect of osteoporosis on fracture healing; however, clinical data do not appear to corroborate with this. Evidence does not support a delay in the initiation of antiresorptive therapy following acute fragility fractures. There is no reason for suspension of osteoporosis medication at the time of fracture if the person is already on treatment. Teriparatide treatment may shorten fracture healing time at certain sites such as distal radius; however, it does not prevent non-union or influence union rate. The positive effect on fracture healing that romosozumab has demonstrated in animals has not been observed in humans. Conclusion: Overall, there appears to be no deleterious effect of osteoporosis medications on fracture healing. The benefit of treating osteoporosis and the urgent necessity to mitigate imminent refracture risk after a fracture should be given prime consideration. It is imperative that new radiological and biological markers of fracture healing be identified. It is also important to synthesize clinical and basic science methodologies to assess fracture healing, so that a convergence of the two frameworks can be achieved. [ABSTRACT FROM AUTHOR]

The article discusses the case of a Belgian Malinois dog with colorectal pythiosis with partial obstruction and marked colonic dilatation. Topics discussed include tenesmus, hematochezia, intermittent chronic diarrhea and weight loss presented by the dog, the cytological, histopathological and laboratory findings, and euthanasia performed on the dog due to financial constraints and poor prognosis.

The diagnosis and treatment of non-unions still represents an interdisciplinary challenge. Therefore, prevention, early detection and specific treatment are of great importance. Non-unions of the upper extremities, although less common than that of the lower extremities, requires special attention for successful treatment due to the central role of the shoulder girdle and arm in day to day activities. Successful treatment of non-unions requires a comprehensive evaluation of the patient's medical history, a thorough clinical examination and in particular radiological imaging. In order to effectively treat the pseudarthrosis it is crucial to distinguish between pseudarthroses that are suspected to be due to infections and those that are not. This article presents a treatment algorithm for managing both pseudarthrosis due to infection and pseudarthrosis without infection in the upper extremities. [ABSTRACT FROM AUTHOR]

This work aims to reveal the effect of cyclic disturbance frequency, i.e., 0.01, 0.1, 0.5, and 1.0 Hz, on damage cracking and energy dissipation characteristics of rock‐backfill composite structure specimens. Testing results show that fatigue volumetric strain and secant modulus increase with increasing disturbance frequency; low‐frequency disturbance leads to an earlier volume expansion. In addition, the strain energy density increases with increasing disturbance frequency. Most of the energy are dissipated for the specimen under high‐frequency disturbance. Finally, computed tomography scanning reveals the influence of disturbance frequency on failure modes; tensile‐splitting failure and shear failure are likely to occur at the surrounding rock subjected to high‐ and low‐ frequency disturbances. Low‐frequency‐disturbed stress seems easily to stimulate cracks at the rock‐backfill interfaces and the backfill; the backfill can absorb much more energy than high‐frequency circumstances. It is suggested that the role of backfill in energy absorption, contact support, and stress isolation is disturbance frequency dependent. Highlights: The effects of cyclic disturbance frequency on damage‐cracking are revealed.The energy dissipation magnitude is negatively correlated to the disturbance frequency.Cracking at interfaces and backfill is relatively severe under low frequency disturbance.The backfill can absorb much more energy under low‐frequency disturbance conditions. [ABSTRACT FROM AUTHOR]

This paper is concerned with environmental corrosion during service of load‐bearing aluminum alloys fabricated by additive manufacturing (AM) with a focus on damage evolution characterization and identification of dominated failure mechanisms of pre‐corroded selective laser melted aluminum alloy. An experimental strategy for analysis of the damage and failure process is presented, combining 3D surface measurement, 3D digital image correlation, and scanning electron microscopy, to provide a multi‐source experimental characterization of corrosion morphology, strain field evolution, and fracture morphology. Statistics and machine learning methods were employed to process the measured multi‐source experimental data, showing that local average roughness has a strong influence on macro‐crack initiation position. The analysis focuses on four primary types of fatigue micro‐crack initiation, namely, internal defect, diffuse corrosion, corrosion micro‐pit, and corrosion jut; internal defect and diffuse corrosion are unique features for powder bed fusion (PBF) AlSi10Mg. The micro‐crack initiation mechanisms for all four types are (i) local stress concentrations due to adjacent material micro‐structural defects, (ii) interaction of underlying alloy microstructure and corrosion‐induced stress/strain, and (iii) local stress/strain concentration at corrosion micro‐pit and jut, respectively. Highlights: Fatigue damage and failure mechanism of pre‐corroded SLM AlSi10Mg were investigated.Experimental strategy was proposed to provide associated multi‐source information.Effect of corrosion morphology characteristics on macro‐crack initiation was evaluated.Main fatigue micro‐crack initiation forms and corresponding mechanisms were analyzed. [ABSTRACT FROM AUTHOR]

This study aimed to assess the reliability and safety of transoral endoscopic-assisted reduction internal fixation (TERIF) for treating short-segment condylar neck fractures (CNF), including hardware removal. Patients with displaced CNF and short condylar segments treated using TERIF were included in the study. Clinical evaluation covered dental occlusion, range of mouth opening, deviation during mouth opening, protrusion, laterotrusion, pain, and chewing. Radiological evaluation was used to assess fracture displacement, angulation, head dislocation, postoperative reduction, fixation stability, and bone healing. The same technique was used to treat 15 patients with 18 CNF and short condylar segments. Hardware removal was performed for nine fractures in eight patients after fracture healing using the same approach. All patients regained satisfactory, pain-free mouth opening with no deviation and complete bone healing. Computed tomographic images displayed adequate reduction and stable fixation during the follow-up period for all patients. No temporary or permanent facial nerve impairment occurred in any of the patients. TERIF is a reliable and safe treatment for CNF with short condylar segments, even in the presence of head dislocation, medial override, and malunited fractures; hardware can be safely removed after healing using the same approach. [ABSTRACT FROM AUTHOR]

Recent pressure on scientists and industries to use renewable resources, as well as the need to produce environmentally friendly materials, has led researchers and manufacturers to use natural fibres as possible reinforcements for their composites. Although they seem to be "ideal" due to their low cost, light weight and interesting energy absorption properties, they cannot be compared to synthetic fibres. To solve this problem, hybridization techniques can be considered, since the combination of synthetic and natural fibres allows for good performances. The aim of this study was to characterize the delamination and in-plane crashworthiness behaviour of carbon, flax and hybrid composites from experimental and numerical points of view. Double Cantilever Beam and Four-Point End Notched Flexure tests were carried out to determine the interlaminar fracture modes. In-plane crashworthiness tests were then performed to investigate the delamination phenomenon and the energy absorption capacity considering two different geometries: flat and corrugated. Numerical models were created and validated on both geometries, comparing the obtained load–displacement curves with the experimental ones. Crush force efficiency and specific energy absorption were quantified to provide a proper comparison of the investigated materials. The good results achieved represent a promising starting point for the design of future and more complex structures. [ABSTRACT FROM AUTHOR]

Rhodiola rosea, a long-lived herbaceous plant from the Crassulaceae group, contains the active compound salidroside, recognized as an adaptogen with significant therapeutic potential for bone metabolism. Salidroside promotes osteoblast proliferation and differentiation by activating critical signaling pathways, including bone morphogenetic protein-2 and adenosine monophosphate-activated protein kinase, essential for bone formation and growth. It enhances osteogenic activity by increasing alkaline phosphatase activity and mineralization markers, while upregulating key regulatory proteins including runt-related transcription factor 2 and osterix. Additionally, salidroside facilitates angiogenesis via the hypoxia-inducible factor 1-alpha and vascular endothelial growth factor pathway, crucial for coupling bone development with vascular support. Its antioxidant properties offer protection against bone loss by reducing oxidative stress and promoting osteogenic differentiation through the nuclear factor erythroid 2-related factor 2 pathway. Salidroside has the capability to counteract the negative effects of glucocorticoids on bone cells and prevents steroid-induced osteonecrosis. Additionally, it exhibits multifaceted anti-inflammatory actions, notably through the inhibition of tumor necrosis factor-alpha and interleukin-6 expression, while enhancing the expression of interleukin-10. This publication presents a comprehensive review of the literature on the impact of salidroside on various aspects of bone tissue metabolism, emphasizing its potential role in the prevention and treatment of osteoporosis and other diseases affecting bone physiology. [ABSTRACT FROM AUTHOR]

Complex fracture reconstruction, malunion, delayed and nonunion are challenging problems often require special attention. Autogenous bone graft for osseous healing has been considered gold standard for decades. It contains viable osteoprogenitor cells, cytokines and growth factors with appropriate tissue matrix resulting in osteogenesis, osteoinduction and osteoconduction. Orthobiologics are biological materials used to augment bone and soft tissue cure, with multifactorial effects. In our study, three orthobiologics i.e., Bone Marrow Aspirate (BMA), Platelet Rich Plasma (PRP) and Decellularized Fish Scale (DFS) were used in conjunction to autogenous bone graft. Objective was to transplant as many cells as possible with osteogenic potential along with the graft. These three regimens were evaluated in terms of clinical vital parameters, hematology, serum analysis, bone biomarkers, mechanical assessment, radiographic evaluation and histomorphometry. We concluded that Bone-BMA combination showed best results in fracture healing and bone remodeling while Bone-PRP combination was below par than Bone-BMA but was superior to Bone-DFS combination. More clinical research may be required before widespread use of these regimens. Furthermore, it is paramount that veterinary orthopedic surgeons must have contemporary knowledge regarding autogenous grafts and orthobiologics, so they can utilize them correctly. [ABSTRACT FROM AUTHOR]

Background and Objectives: Osteoporotic vertebral compression fractures (OVCFs) are prevalent among the elderly, often leading to significant pain, morbidity, and mortality. Effective management of underlying osteoporosis is essential to prevent subsequent fractures. This study aimed to compare the clinical and radiographic outcomes of teriparatide and denosumab treatments in patients with OVCFs to determine their relative effectiveness in improving patient outcomes. Materials and Methods: This retrospective study included 78 patients diagnosed with an acute thoracolumbar OVCF who received either teriparatide (35 patients) or denosumab (43 patients) within three months of a fracture. Clinical outcomes were assessed using the visual analog scale (VAS) for back pain, Oswestry disability index (ODI), and EQ-5D quality of life scores at baseline, 6 months, and 12 months. Bone mineral density (BMD) and radiographic outcomes were evaluated initially and at 12 months post-treatment. Results: Both treatment groups demonstrated significant improvements in VAS, ODI, and EQ-5D scores over 12 months. No significant differences were observed between the teriparatide and denosumab groups in terms of clinical outcomes or radiographic measurements at any time point. Fracture union and BMD improvements were similarly observed in both groups. The teriparatide group had a lower baseline BMD, but this did not affect the overall outcomes. Conclusions: Both teriparatide and denosumab are effective in improving clinical and radiographic outcomes in patients with OVCFs. Despite concerns about denosumab's potential to hinder fracture healing, our study found no significant differences between the two treatments. These findings support the use of denosumab for early treatment of OVCFs to prevent subsequent fractures without compromising fracture healing. Further prospective studies are needed to confirm these results. [ABSTRACT FROM AUTHOR]

To determine the presence of a consistent osseous corridor from the lateral-posterior aspect of the anterior inferior iliac spine to the sacral wing that could be used for safe trans percutaneous screw fixation for pelvic fragility fractures of the iliac wing and fracture dislocations of the sacroiliac joint (FFP types IIIa and IIIb). Computed tomography (CT) scans were obtained from 100 patients and imported to Mimics software for 3D reconstruction. Then, a cylinder was drawn to imitate the modified LC-II screw and adjusted to a maximum radius and length to obtain the feasible region. Thirteen parameters of the osseous corridor of the modified LC-II screw were measured. Differences between sex groups were compared, and significant statistical correlations were carefully studied to determine potentially important clinical relationships. The records of patients with FFP type IIIa and IIIb fragility fractures of the pelvis were extracted from our hospital. Patients who underwent modified LC-II screw fixation, LC-II screw fixation or reconstruction plate fixation were included. Patients' operative characteristics and complications were recorded at follow-up. Fracture reduction quality was assessed using the Matta standard. Functional outcomes were evaluated using the Majeed grading system. The mean maximum diameters of the osseous corridors of the modified LC-II screw in males and females were 12.73 and 10.83 mm, respectively. The mean maximum lengths of the osseous corridors of the modified LC-II screw in males and females were 96.37 and 93.37 mm, respectively. In the treatment of patients with FFP IIIa and FFP IIIb fractures, the group of treatment by the modified LC-II screws fixation was shown significantly shorter operative time and fewer intraoperative blood loss in comparison to that by the reconstruction plates. In the present study, all the males and females had a complete osseous corridor of the modified LC-II screw. The clinical results of the patients who were treated with modified LC-II screw fixation suggest that the novel method has a good preliminary outcome. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusions The exact relationship among atypical periprosthetic femoral fractures (APFFs), typical periprosthetic femoral fractures (PFFs), and atypical femur fractures (AFFs) remains unclear. This study aimed to investigate the prevalence of APFFs among PFFs and to identify the clinical characteristics, management, and prognosis that distinguish APFFs from typical PFFs and AFFs to further determine the relationship among these three fracture types.In this retrospective study, we reviewed the clinical data of 117 consecutive patients who had PFFs after hip arthroplasty between January 2012 and December 2022 and further classified them into an APFF group and a typical PFF group according to the revised ASBMR diagnostic criteria for AFF. Moreover, patients who had subtrochanteric or femoral shaft fractures in the same period and met the diagnostic criteria for AFF were recruited and classified into the AFF group. Demographic information, minor features of AFF, comorbidities, history of medication usage, management, and complications were collected and compared among patients with typical PFFs, APFFs, and AFFs.Eleven PFFs were identified as APFFs, and the prevalence of APFFs among PFFs was 9.4%. Significant differences were found in generalized increase in cortical thickness (p = 0.019), prodromal symptoms (p < 0.001), and the incidence of bilateral fractures (p = 0.010) among the groups, where the incidences of these minor features in the APFF group and the AFF group were higher than those in the typical PFF group. Of note, the duration of fracture healing of APFFs was significantly longer than that of typical PFFs and AFFs (p < 0.001 and p = 0.004, respectively). In addition, the APFF group and the AFF group had higher proportions of patients with rheumatoid arthritis (p = 0.004 and p = 0.027, respectively), bisphosphonate (BP) usage (p = 0.026 and p < 0.001, respectively), and longer duration of BP usage (p = 0.003 and p = 0.007, respectively) than the typical PFF group. Furthermore, significant differences were found in management (p < 0.001) and complication rate (p = 0.020) among the groups, and the rate of complications in the APFF group and the AFF group was higher than that in the typical PFF group.APFFs not only fulfilled the mandatory and major diagnostic criteria for AFF but also had many clinical characteristics, management and prognosis distinguishing them from typical PFFs but resembling AFFs; hence, the diagnostic criteria for AFF might be revised to incorporate APFF as a distinct subtype of the condition. [ABSTRACT FROM AUTHOR]

Objective To compare the efficacy of triangular anchor reduction forceps and towel forceps in the treatment of long oblique or spiral distal tibial fractures. Methods The data of 58 patients admitted to the Department of Traumatic Orthopaedics in Second Affiliated Hospital of Anhui Medical University from June 2019 to March 2021 were analyzed prospectively. According to the reduction methods during operation, they were divided into point reduction forceps group (n = 26) and triangle anchor reduction forceps group (n = 32) . The operation time, intraoperative fluoroscopy times, intraoperative blood loss, postoperative fracture reduction quality, hospital stay, fracture healing time, American orthopedic foot and ankle society (AOFAS) score, curative effect and complications at the last follow-up were compared between the two groups. Results All patients participated in the follow-up for more than one year. There was no significant difference in age, sex, basic diseases and injury mechanism between the two groups. The operation time and fluoroscopy times of patients in triangle anchor reduction group were significantly lower than those in point reduction forceps group (P < 0.05), while the quality of fracture reduction was higher than that in point reduction forceps group (P < 0.05), and there was no significant difference in other perioperative indexes. The fracture healing time of patients in triangle anchor reduction group was shorter, and the ankle joint function was better than that in point reduction forceps group (P < 0.05) . There was no significant difference in the incidence of various complications between the two groups, but the overall incidence of complications in the triangle anchor reduction group was significantly lower (P < 0.05) . Conclusion Triangular anchor reduction forceps can improve the quality of fracture reduction, shorten the healing time of fracture, reduce the occurrence of complications, reduce the operation time and the number of fluoroscopy during operation, and there is no obvious increase in local infection. It is an effective and reliable reduction method. [ABSTRACT FROM AUTHOR]

The present work describes for a first time a fused fracture of the metacarpals of the medium-sized felid, Lynx issiodorensis, the putative ancestor of all Eurasian extant lynx species. The studied remains, four metacarpals from the same individual, were unearthed from the Early Pleistocene of the Taurida cave (Crimean Peninsula) and studied through computed tomography. These remains exhibit pronounced signs of osteopathology, namely, fracture with displacement of the fifth metacarpal bone fused with the formation of callus and deformation of the bone itself. The pathological process is spread to adjacent metacarpal bones. The likely cause of the injury could be an unsuccessful hunt or an awkward landing from a height. After the injury and in the process of healing the fracture, the studied individual survived with clearly limited hunting abilities. [ABSTRACT FROM AUTHOR]

Introduction: Periprosthetic femoral fractures (PFFs) following hip arthroplasty, especially Vancouver B2 and B3 fractures, present a challenge due to the association with a loose femoral stem, necessitating either open reduction and internal fixation or stem revision. This study aims to compare outcomes between uncemented and cemented stem revisions in managing Vancouver B2 and B3 fractures, considering factors such as hip-related complications, reoperations, and clinical outcome. Methods: A retrospective cohort study was conducted at Danderyd Hospital, Sweden, from 2008 to 2022, encompassing operatively treated Vancouver B2 and B3 fractures. Patients were categorized into uncemented and cemented stem revision groups, with data collected on complications, revision surgeries, fracture healing times, and clinical outcomes. Results: A total of 241 patients were identified. Significant differences were observed between the two groups in patient demographics, with the cemented group comprising older patients and more females. Follow up ranged from 1 to 15 years. Average follow up time was 3.9 years for the cemented group and 5.5 years for the uncemented group. The cemented stems demonstrated lower rates of dislocation (8.9% versus 22.5%, P = 0.004) and stem loosening (0.6% versus 9.3%, P = 0.004) than the uncemented method. Moreover, the cemented group exhibited shorter fracture healing times (11.4 weeks versus 16.7 weeks, P = 0.034). There was no difference in clinical outcome between groups. Mortality was higher in the cemented group. Conclusions: This retrospective study indicates that cemented stem revision for Vancouver B2–3 fractures is correlated with lower dislocation and stem loosening rates, necessitating fewer reoperations and shorter fracture healing times compared with the uncemented approach. The cemented group had a notably higher mortality rate, urging caution in its clinical interpretation. Level of evidence III [ABSTRACT FROM AUTHOR]

Current treatments do not support direct exposure of fracture fragments, resulting in the inability to directly observe the articular surface during surgery for accurate reduction and firm fixation. The aim of the study was to explore the treatment effect of digital virtual reduction combined with individualized guide plate of lateral tibial condyle osteotomy on tibial plateau fracture involving the lateral posterior condyle collapse. 41 patients with tibial plateau fracture involving the lateral posterior condyle collapse were recruited in the trial. All patients underwent Computed Tomography (CT) scanning before operation. After operation, fracture reduction was evaluated using Rasmussen score and function of knee joint was assessed using hospital for special surgery (HSS) score. 41 patients were followed-up 6–26 months (mean, 15.2 months). Fracture reduction was good after operation, with an average of 13.3 weeks of fracture healing without serious complications. The excellent and good rate was 97.6%. The joint movement degree was -5∘∼0∘∼135∘ with an average of 125.5∘. Digital virtual reduction combined with individualized guide plate of lateral tibial condyle osteotomy was effectively for treating tibial plateau fracture involving the lateral posterior condyle collapse. [ABSTRACT FROM AUTHOR]