Bone is a unique tissue that is capable of repairing itself after damage. However, there are certain instances of fractures and defects that require clinical intervention for proper alignment and ...healing. As with any implant, careful consideration of the material used to create the implants to treat these problems is needed. If the incorrect material is chosen, the implants themselves can lead to bone fractures or defects, or bone healing may not take place at all. All three classes of biomaterials–metals, ceramics, and polymers–have been used in the treatment of both bone fractures and bone defects, and each has its own unique benefits and limitations for its applications. Furthermore, composites of these different materials have also been created to try to take advantage of all the different benefits offered by each different material. This review highlights different materials that have been used for the development of internal fixators and bone graft substitutes to treat fracture and bone defects as well as their limitations and needed future research.
•Vascular endothelial Piezo1 distribution in bone was explored.•Deletion of endothelial Piezo1 resulted in impaired bone fracture repair.•Bone fracture lesions of endothelial Piezo1 deficient animals ...exhibited reduced calpain activity, PI3K-AKT phosphorylation and Notch signaling.
Piezo1, a calcium-permeable non-selective cationic channel that senses mechanical stimulation in multicellular organisms, mediates various biological processes, including angiogenesis. The supply of nutrients and oxygen through newly formed blood vessels at the fractured lesion is critical for bone fracture repair. The elucidation of the underlying mechanisms involved in angiogenesis and bone repair can aid in improving fracture healing. Here, mice with endothelial cell-specific deletion of Piezo1 channels were used to examine the role of Piezo1 in the initiation of fracture healing. The expression and distribution of Piezo1 was explored in the vasculature of the bone. The deletion of endothelial Piezo1 resulted in impaired bone fracture repair, downregulation of calcium-activated proteolytic calpain activity during vascularization, inhibition of osteoblast maturation and ossification, downregulation of phosphorylated PI3K-AKT, and impaired Notch signaling during bone fracture union. These findings indicated that Piezo1 protein is a potential target for enhancing bone regeneration and treating delayed or nonunion bone fractures.
Piezo 1 channels promote angiogenesis and play key roles in vascular biology. EC-specific Piezo 1 deletion was associated with Ca2+signaling in regulating local vascular growth which has great importance in supporting bone fracture repair Display omitted .
Drilling of bone: A comprehensive review Pandey, Rupesh Kumar; Panda, S.S
Journal of clinical orthopaedics and trauma,
03/2013, Letnik:
4, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract Background Bone fracture treatment usually involves restoring of the fractured parts to their initial position and immobilizing them until the healing takes place. Drilling of bone is common ...to produce hole for screw insertion to fix the fractured parts for immobilization. Orthopaedic drilling during surgical process causes increase in the bone temperature and forces which can cause osteonecrosis reducing the stability and strength of the fixation. Methods A comprehensive review of all the relevant investigations carried on bone drilling is conducted. The experimental method used, results obtained and the conclusions made by the various researchers are described and compared. Result Review suggests that the further improvement in the area of bone drilling is possible. The systematic review identified several consequential factors (drilling parameters and drill specifications) affecting bone drilling on which there no general agreement among investigators or are not adequately evaluated. These factors are highlighted and use of more advanced methods of drilling is accentuated. The use of more precise experimental set up which resembles the actual situation and the development of automated bone drilling system to minimize human error is addressed. Conclusion In this review, an attempt has been made to systematically organize the research investigations conducted on bone drilling. Methods of treatment of bone fracture, studies on the determination of the threshold for thermal osteonecrosis, studies on the parameters influencing bone drilling and methods of the temperature measurement used are reviewed and the future work for the further improvement of bone drilling process is highlighted.
Bone fracture is a very common body injury. The healing process is physiologically complex, involving both biological and mechanical aspects. Following a fracture, cell migration, cell/tissue ...differentiation, tissue synthesis, and cytokine and growth factor release occur, regulated by the mechanical environment. Over the past decade, bone healing simulation and modeling has been employed to understand its details and mechanisms, to investigate specific clinical questions, and to design healing strategies. The goal of this effort is to review the history and the most recent work in bone healing simulations with an emphasis on both biological and mechanical properties. Therefore, we provide a brief review of the biology of bone fracture repair, followed by an outline of the key growth factors and mechanical factors influencing it. We then compare different methodologies of bone healing simulation, including conceptual modeling (qualitative modeling of bone healing to understand the general mechanisms), biological modeling (considering only the biological factors and processes), and mechanobiological modeling (considering both biological aspects and mechanical environment). Finally we evaluate different components and clinical applications of bone healing simulation such as mechanical stimuli, phases of bone healing, and angiogenesis.
Pure metals and their alloys are used to partially or completely restore bone fractures. Biodegradable metals emerged as promising candidates for fracture fixation devices since they are able to ...self-degrade in the body environment. The main challenge of the devices is to reach an adequate degradation rate relative to the bone healing and also to present safe degradation by-products. Magnesium alloys are very much studied because of their promising properties, but the main limitation for their application in biomedical devices is the hydrogen evolution that results from their corrosion in aqueous media. This work assesses the effects of low potential anodizing process of AZ91 alloys in basic media on surface topography, electrochemical response, hydrogen evolution and cell attachment compared with the non-treated alloys. A comparative approach to determine the electrochemical parameters for assessing the degradation rate is also discussed. Results show that the electrochemical treatment of anodizing at low voltage in 5 mol/L KOH solution generates magnesium oxide/hydroxide on the surface which could act as a barrier to prevent fast degradation, and consequently to reduce hydrogen release. In turn, this treatment improved the adhesion of bovine embryonic fibroblasts (BEFs) and MCT3T3 pre-osteoblastic cells to the surface, showing that it could be a good candidate to be used in temporary implants.
PURPOSEThe main objective of this study was to compare radiologists' performance without and with artificial intelligence (AI) assistance for the detection of bone fractures from trauma emergencies. ...MATERIALS AND METHODSFive hundred consecutive patients (232 women, 268 men) with a mean age of 37 ± 28 (SD) years (age range: 0.25-99 years) were retrospectively included. Three radiologists independently interpreted radiographs without then with AI assistance after a 1-month minimum washout period. The ground truth was determined by consensus reading between musculoskeletal radiologists and AI results. Patient-wise sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for fracture detection and reading time were compared between unassisted and AI-assisted readings of radiologists. Their performances were also assessed by receiver operating characteristic (ROC) curves. RESULTSAI improved the patient-wise sensitivity of radiologists for fracture detection by 20% (95% confidence interval CI: 14-26), P< 0.001) and their specificity by 0.6% (95% CI: -0.9-1.5; P = 0.47). It increased the PPV by 2.9% (95% CI: 0.4-5.4; P = 0.08) and the NPV by 10% (95% CI: 6.8-13.3; P < 0.001). Thanks to AI, the area under the ROC curve for fracture detection of readers increased respectively by 10.6%, 10.2% and 9.9%. Their mean reading time per patient decreased by respectively 10, 16 and 12 s (P < 0.001). CONCLUSIONSAI-assisted radiologists work better and faster compared to unassisted radiologists. AI is of great aid to radiologists in daily trauma emergencies, and could reduce the cost of missed fractures.
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