One of healthcare’s scarier little secrets is how extremely tricky it can be to accurately place screws into spinal pedicles during surgery. In fact, a few years ago five experienced surgeons were reportedly asked to manually insert hardware used to strengthen fused vertebrae into cadavers. When researchers reviewed a follow-up CT scan, they found placement error rates as high as 41%. Even worse, 21 of the screws surgeons implanted penetrated the medial wall of the pedicles and entered the vertebral canals.