Published online Apr 18, 2014. doi: 10.5312/wjo.v5.i2.112
Revised: February 11, 2014
Accepted: March 13, 2014
Published online: April 18, 2014
Pedicle screw instrumentation has been used to stabilize the thoracolumbar spine for several decades. Although pedicle screws were originally placed via a free-hand technique, there has been a movement in favor of pedicle screw placement with the aid of imaging. Such assistive techniques include fluoroscopy guidance and stereotactic navigation. Imaging has the benefit of increased visualization of a pedicle’s trajectory, but can result in increased morbidity associated with radiation exposure, increased time expenditure, and possible workflow interruption. Many institutions have reported high accuracies with each of these three core techniques. However, due to differing definitions of accuracy and varying radiographic analyses, it is extremely difficult to compare studies side-by-side to determine which techniques are superior. From the literature, it can be concluded that pedicles of vertebrae within the mid-thoracic spine and vertebrae that have altered morphology due to scoliosis or other deformities are the most difficult to cannulate. Thus, spine surgeons would benefit the most from using assistive technologies in these circumstances. All other pedicles in the thoracolumbar spine should theoretically be cannulated with ease via a free-hand technique, given appropriate training and experience. Despite these global recommendations, appropriate techniques must be chosen at the surgeon’s discretion. Such determinations should be based on the surgeon’s experience and the specific pathology that will be treated.
Core tip: Pedicle screws are currently placed in the thoracolumbar spine via three main techniques: free-hand, fluoroscopy guidance, and stereotactic navigation. Various studies have reported success with each of these techniques. However, it is clear that there is some difficulty in comparing such studies due to differing definitions of accuracy and methods of evaluation. Regardless, it is evident that image-assisted techniques provide some benefit when cannulating mid-thoracic vertebral levels and vertebrae that have altered morphology due to deformation from complex pathologies. However, a surgeon’s ultimate decision must be based on individual experience and comfort with a given technique.