Monitoring of fracture healing by electrical conduction: A new diagnostic procedure

Abstract

Background:Electrical stimulation of fractures has been reported to enhance fracture healing. X-rays are normally used to assess union of fractures. Electrical conduction is not tried as a tool to study fracture healing. The current study focuses on electrical conduction as a diagnostic tool to assess fracture healing and new bone formation. The aim was to find if electrical resistance across the fracture can be used as a tool to study fracture healing which can be verified with simultaneous radiographs.Materials and Methods:A prospective study was conducted where 12 open fractures of tibia, including two with bone defects were evaluated. They were debrided and four-carbon ring Ilizarov external fixators were applied. Their healing was followed with clinical assessment and periodical X-rays till the endpoint of fracture union and then the rings were removed. In addition, all these cases also had application of electrical voltage in the range of 0.1–1.0 V DC in 0.1 V increments, across the two wires on either side of fracture. The output current was recorded by an ammeter connected in series. Resistance calculated for various voltages was plotted as a graph for the period of fracture treatment and the characteristics were studied. This graph was compared with the appearance of new bone in the X-rays.Results:In all cases, when the above graph stabilized, in the consecutive recordings, the X-rays showed healing (bridging callus) matching the curve and the patient was able to load the limb. The time of stabilization of this graph for a specific voltage was different in individual cases. However, for a given case, the resistance characteristics were the same for the entire voltage range of 0.1–1.0 V.Conclusion:If the resistance versus day curve stabilizes on the consecutive recordings, we can predict that the fracture is in the process of healing. This stabilization period also matched the patients’ ability to comfortably load the limb and also the radiographs which showed bridging callus (healing). If this is used as a positive criterion for fracture healing in future, the radiation exposure by X-rays shall be less.

Change in electrical properties of bone as diagnostic tool for measurement of fracture healing

“…Characterization of various bone tissues by multifrequency systems can also be beneficial 24 . A broadband signal for measuring electrical impedance containing maximum length sequence system and linear time variant systems can also be used to give additional spectral information necessary for diagnosing early non-unions 28 . However, further research is required to reduce the noise.…”

Establishment of a Numerical Model to Design an Electro-Stimulating System for a Porcine Mandibular Critical Size Defect

“…This was done on the assumption that during the healing process the formerly soft cancellous bone develops and begins to resemble more structured and dense cortical bone [63]. Recent studies proposed the electrical properties of bone as a biomarker for bone fracture healing [64], e.g., increasing bone resistance as an indicator for bone fracture healing [65]. Hence, we may assume that the electrical conductivity in the defect domain-formerly being cancellous bone-decreases and approaches that of cortical bone during bone remodeling.…”

New opportunities for fracture healing detection: Impedance spectroscopy measurements correlate to tissue composition in fractures

“…Because EIS can capture changes in dielectric properties and a healing fracture is dominated by different tissues, it may be able to uniquely complement a technique like X‐ray that relies on tissue mineralization by providing quantitative local information about the fracture callus, particularly at early stages. In addition, prior work has used EIS to track differences over healing time between fracture and control groups . While these data are promising, these studies are limited to fractures treated via external fixation using long metal pins as electrodes.…”

“…In addition, prior work has used EIS to track differences over healing time between fracture and control groups. [18][19][20][21][22] While these data are promising, these studies are limited to fractures treated via external fixation using long metal pins as electrodes. These results as well as other work involving noninvasive measurements [23][24][25] suffer from limited dynamic range due to noise from surrounding soft tissue.…”