RESUMO
Although spinal fusion has been the definitive surgical management of symptomatic lumbar degenerative conditions, continued reports of adjacent level degeneration and suboptimal patient outcomes have prompted the advancement of motion-preserving technology. Posterior dynamic stabilization [PDS] devices are designed to maintain native motion while providing indirect foraminal decompression and off-loading of the facets and posterior anulus. Posterior dynamic stabilization systems relying on pedicle screws as vertebral anchors have the advantage of surgeon familiarity with screw placement technique and instrumentation. Interconnections between the screws serve as a tension band to resist posterior distractive forces during flexion and maintain foraminal height in extension. Short-term results of pedicle screw-based PDS systems show comparable pain relief to traditional fusion with the added advantage of retained motion and potential reduction of fusion-related morbidity and of the incidence of adjacent segment degeneration. As with most new technology, pedicle screw based PDS systems require further evaluation to determine their long-term clinical benefit