The Era of Cortical Bone Trajectory Screws in Spine Surgery: A Qualitative Review with Rating of Evidence

The use of cortical bone trajectory (CBT) pedicle screws for posterior fixation and fusion seems to constitute a viable alternative for spinal procedures, with the potential to mitigate risks, be minimally invasive, and cause less tissue damage than the traditional technique. This review analyzes the literature regarding CBT according to the rate of evidence of articles and their main focus. CBT has proved to be a safe and viable option for screw fixation in spine sup gery. Given the denser bone interception, high-quality biomechanics studies show equal or even better properties compared with classic pedicle screw fixation, depending on several factors such as screw size and length. Through the years, surgical technique has improved to gain a longer and safer trajectory than first described, Level 2 and 3 clinical studies suggest equal clinical and radiologic outcomes compared with pedicle trajectory fixation, but high-quality, level 1, randomized controlled trials are needed to confirm these results.