Quantifying Load-Sharing in Spinal Fusion Using Strain Sensor-Equipped Fusion Rods and Force Sensor-Equipped Intervertebral Cages

• ETH Zurich
• Energy Efficient Circuits and IoT Systems (Jang)

Lumbar interbody fusion has proved to be a successful approach for addressing spinal pathologies. However, complications such as pseudarthrosis and implant failure may arise, potentially requiring revision surgery. These complications are are frequently mechanical in origin, highlighting the importance of understanding the mechanical function of different components within a spinal fusion system. A spinal fusion system can be divided into three main components: anatomical structures, posterior instrumentation, and, if present the intervertebral cage. To investigate the biomechanical behavior of these components, we need to measure or calculate the loads on each of them. The load on the intervertebral cage can be directly measured using cages equipped with force load cells, a technology that has been developed within our research group. Additionally, the load on the fusion rods can be measured by utilizing fusion rods equipped with strain gauges. This methodology has been employed in a previous study conducted by our group, although the strain gauges may require further refinement. By quantifying the loads on the cages and rods, it is possible to infer the load distribution on the anatomical structures.

• Clinical Engineering, Orthopaedics
• Internship, Master Thesis, Semester Project