Percutaneous pedicle screws

Minimally invasive techniques in pedicle screw insertion provide an additional option to a spine surgeon’s armamentarium in dealing with various spine pathologies. It can be applied to practically any surgical setting where conventional open technique is indicated. The most apparent advantage of percutaneous pedicle screw insertion relates to reduced paraspinal muscle damage. Studies have shown that this decreased approach-related morbidity results in decreased operative blood loss, reduced postoperative narcotic use, and greater preservation of trunk extension strength. Because direct visualization of anatomic landmarks is sacrificed, intraoperative imaging is necessary to facilitate safe pedicle screw placement. Two common methods of percutaneous pedicle screw insertion are discussed in this chapter. The first is with real-time two-dimensional (2-D) fluoroscopic imaging. The second is with three-dimensional (3-D) image-guided navigation which employs virtual images taken with an intraoperative CT scanner. Accuracy rates with either method have been demonstrated to be similar or improved compared to open technique. The benefit of improved imaging technology is associated with increased radiation exposure risk. This can be minimized by wearing protective garments, observing safe distance from the beam source, and limiting or eliminating unnecessary exposure.