There is currently no standardized method of fracture healing assessment, and doctors rely on X-
Rays that are only useful in the later stages of repair.
Using an in vivo mouse fracture model, we propose that microscale devices be implanted after
Using electrical impedance spectrum (EIS)
Track healing tissues with high sensitivity.
In this study, we fixed long backbone fractures in mice with external fixators and bone plates.
EIS measurements performed on two microelectrodes within the fracture space were able to track longitudinal differences between well-healed and poorly-healed individual mice.
In addition, we also propose an equivalent circuit model combining EIS data to classify fracture repair states.
Finally, we show that EIS measurements are closely related to standard quantitative ct values and that these correlations are clinically validated
Frequency of work related to the implementation of this technology.
These results suggest that EIS can be integrated into current fracture management strategies, such as bone plates, to provide physicians with quantitative information on fracture repair status to guide clinical decisions
For the patient.
Skeletal muscle damage is one of the most serious disabling diseases in the United States, with a total number of fractures ranging from 12 to 15 million each year.
The treatment of these fractures is a huge burden for the United States. S.
The health care system is estimated at $23 for hospital expenses.
2004 4 billion.
Determining the quality of fracture healing is critical for patients to make correct clinical decisions, but several studies have pointed out that there is a lack of standardized methods to assess fracture healing.
Radiography and physical evaluation are two commonly used methods for clinical monitoring of fracture healing. Plain X-
Radiography is often used, but studies have shown that these radiography are poorly correlated with bone strength, do not have sufficient accuracy to define healing, and are not reliable for determining the stage of fracture repair.
Computed tomography (CT)Double energy X-
Ray absorption method (DEXA)
, Ultrasound can provide a better diagnostic capability, but is limited in clinical use mainly due to cost and high radiation dose.
Doctors often rely on physical examinations, but these tests are subjective and may result in inaccurate assessments.
Fracture Healing is performed through a combination of two pathways: Intra-membrane (direct)
And within the cartilage (indirect)ossification.
At the beginning of the fracture injury, the formation of the hematoma will trigger
Inflammation cascade (Stage 1).
After this, the endometrium and the premembrane cells perform in-membrane bone formation in a highly stable area and directly form the bone.
In the fracture space, there is more movement, and the new bone is indirectly formed from the middle of the cartilage through the process of bone formation in the cartilage (Stage 2).
The proliferation and maturation of cartilage cells, and then the promotion of mineralization, resulting in the transformation of cartilage into a trabecular bone (Stage 3)
And then converted it into a functional cortical bone (Stage 4).
The healing stages of these four definitions have good features in terms of histology, but especially in the early stages, like X-
Rays dependent on bone mineralization.
Monitoring fracture healing is an active field of academic research, but most work is focused on obtaining mechanical feedback on strain measurements related to bone strength.
In this study, we used electrical techniques to characterize the progress of fracture repair, which was carried out on the basis of previous measurements of electrical changes in cells and tissues.
Electricity, the tissue can be modeled as a combination of resistance and capacitance effects. The ion-rich intra-
The extracellular matrix conducts charge, so it can be modeled as resistance, while
The layered cell membrane is a barrier for charge flow and can be modeled as a capacitor or a constant phase element (CPE).
Electrical impedance spectrum (EIS)
Measurement frequency-
The dependency combination of these components describes the flow of current through the material.
Complex impedance can be represented by resistance R and impedance X.
There is a large amount of literature proving the use of this method.
Known as the "bioimpedance" method, used to quantitatively characterize cell changes, primarily reflecting cell membrane integrity, cell volume, and in-cell conductivity
And extra-cellular components
Previous work has detailed the use of EIS to describe the dielectric and conductive properties of many biological tissues, including porous and dense bones.
We also show the use of EIS in the model system to distinguish tissue components in fracture healing tissues.
Although previous studies have used EIS to evaluate and model fractures, their detection is limited due to noise in the surrounding soft tissue, limited sensitivity caused by electrode placement, and insufficient histological analysis.
Here, we present the development and testing of the micro-scale EIS sensor, which aims to measure the electrical properties of fracture healing during fracture healing vertically in two different mouse fracture models.
As far as we know, this is the first study to implant a micro-sensor directly in the fracture space, able to perform local measurements of the changing healing tissue.
By doing so, we demonstrate the ability of our sensors to distinguish between Cure and bad
Using a miniature external fixer or bone plate-stabilized healing fracture, it was found that the spectrum of impedance measurements was closely related to quantitative measurements of bone volume and bone density. The long-
The term vision is that these EIS sensors can quantitatively monitor the progress of healing by regularly measuring at fracture sites, thereby enhancing current clinical care and further achieving an early assessment of the risk of non-healing.
The global orthopaedic equipment market is expected to reach $41.
From 2 billion to 2019, we believe that the smart implant system has great potential, which can be integrated with the existing orthopedic hardware platform to provide physicians with information about the healing trajectory of each individual patient. Our proof-of-
Conceptual research is an important step in supporting EIS as a simple and low feasibility
Cost Approach for clinical delivery
Relevant information during fracture management.