Bioelectronic osteosynthesis plate to monitor the fracture bone healing using electric capacitive variations

Bone fractures represent a global public health issue. Over the past few decades, a sustained increase in the number of incidents and prevalent cases have been reported, as well as in the years lived with disability. Current monitoring techniques predominantly rely on imaging methods, which can result in subjective assessments, and expose patients to unnecessary cumulative doses of radiation. Besides, they are costly and incapable of providing continuous daily detection of fracture healing stages. Technological advances are still required to design fixation systems with the ability to minimize the risk of delayed healing and nonunion conditions for timely medical intervention, such that preventive procedures can be provided. This work proposes.

An innovative bioelectronic osteosynthesis plate, minimally customized from a fixation device used in clinical practice, was developed to monitor the bone-implant interface to effectively detect the progression of bone fractures stages. Our technology includes a network-architectured capacitive interdigitated system, a Bluetooth module, an analog-to-digital converter, a multiplexer, a microcontroller, and a miniaturized battery.

Both experimental tests with biological tissues and numerical simulations show strong evidence that this bioelectronic implant is able: (i) to detect the four distinct bone healing stages, with capacitance decreases throughout the healing process; and (ii) to monitor the callus formation across multiple target regions.

This work provides a significant contribution to the design of bioelectronic implant technologies for highly personalized sensing of biointerfaces. Our bioelectronic fixation implant supports faster fracture healing, mainly for delayed healing and non-union conditions.