Revolutionizing Postoperative Spinal Fusion Assessment: Implantable Vertebral Sensors, Their Potential, and Future Directions

Introduction: The success of spinal fusion surgery depends on the rate of fusion. Traditional methods to assess spinal fusion such as radiography are limited by cost and radiation exposure, and radiographic assessment does not provide specific information regarding the loads and stresses of the spine. Implantable spinal sensors to monitor spinal load are an emerging opportunity that offer continuous, direct measurement of spinal biomechanics. A review of the types of sensors and their shortcomings is needed to guide future development. This literature review aims to expand the understanding of how implantable vertebral sensors can revolutionize the postoperative assessment of spinal fusion by integrating sensor technology into spinal implants.

Methods: A systematic search by four separate reviewers using PubMed, Embase, and Scopus databases was performed for articles relevant to implantable spinal sensors including sensor type and intended application. Abstract reviews followed by full-text screenings for inclusion were performed. Each article was summarized and results were compiled as a group.

Results: Following the search and abstract screening, 65 articles discussing spinal sensors were included. 50 articles were included after full-text screening. Recent studies have explored the use of various types of spinal sensors to monitor fusion rates post-surgery. Literature suggests that implantable sensors can provide continuous load monitoring to assess spinal fusion status. SMART spinal sensors have been developed for monitoring spinal fusion, and battery-free sensing systems have been proposed for this purpose. Currently, seven unique designs for spinal implants with sensors exist, consisting of piezoelectric strain gauges, thermometers, or accelerometers.

Conclusion : Spinal sensors have the potential to improve the accuracy of measuring fusion rates post-surgery, which can enable surgeons to make data-driven, postoperative care decisions and improve patient outcomes. Sensors are currently limited by size, operational life, associated chemical risks due to biocompatibility issues. Nonetheless, the imperative for the advancement of implantable spinal sensors remains unequivocal, as their potential to revolutionize patient care, enhance understanding of spinal disorders, and pave the way for innovative therapeutic interventions far outweighs any drawbacks they may pose.