In 1992, Graf described the use of the Graf ligamentoplasty system to treat low back pain without fusion. According to his theory, abnormal rotary motion was the primary source of mechanical low back pain. He later improved the Graf ligamentoplasty system by inserting titanium pedicle screw anchors into the vertebra, both superior and inferior to the symptomatic level, and using a braided polypropylene tension band to link the titanium pedicle screws.
About Pedicle Screw/Rod–Based Dynamic Stabilization Devices
Dynamic stabilization is a surgical technique designed to allow for some movement of the spine, while maintaining enough stability to prevent too much movement. Pedicle-based dynamic devices were first designed to stabilize the abnormal segment and to unload degenerated discs and facet joints, while maintaining the same level of normal motion.By unloading the pressure on the degenerated disc and facets, pedicle-based dynamic devices have the potential to reduce pain associated with these anatomical structures. Furthermore, these devices can be used to prevent adjacent-segment disease, either by replacing the whole construct with dynamic rods or by “topping off” the rigid instrumented segment with pedicle-based dynamic devices, avoiding an abrupt change from a rigid construct to the more mobile adjacent segment. It has also been argued that using pedicle-based dynamic devices can promote better fusion because of micromovements across endplates, and can protect from implant failure because of better load sharing through the implant. Finally, these devices can be used to stabilize posterior iatrogenic destabilizing surgery, such as wide laminectomy and facetectomy.