Biomechanical impact of cortical bone vs. traditional pedicle screw trajectories: a finite element study on lumbar spinal instrumentation.

Background: Pedicle screw fixation using the cortical bone trajectory (CBT) enhances stability by engaging cortical bone, offering a valuable alternative to the traditional pedicle screw trajectory (TT). This study used finite element analysis to compare L4-5 instrumentation with CBT and TT screws, investigating whether the increased cortical bone engagement in CBT improves stability but makes it more susceptible to fatigue failure.

Methods: A L3-sacrum model was generated using anonymized CT patient data, validated against existing studies, showing consistent ROM (range of motion) values.

A microfluidic dual gradient generator for conducting cell-based drug combination assays.

We present a microfluidic chip that generates linear concentration gradients of multiple solutes that are orthogonally-aligned to each other. The kinetics of gradient formation was characterized using a fluorescent tracer matching the molecular weight of small inhibitory drugs. Live-cell signalling and motility experiments were conducted to demonstrate the potential uses and advantages of the device.