Long posterior fixation of the spine to the sacrum and pelvis

Abstract

Despite advances in surgical techniques, failure to achieve solid arthrodesis of the lumbosacral junction continues to be a significant clinical disadvantage, especially in long fusions to the sacrum, such as those needed in the treatment of neuromuscular scoliosis, fusions in osteoporotic patients with degenerative scoliosis and adult scoliosis. Complications, including failure of the bone-metal interface, fracture of the implants, loss of alignment and pseudarthrosis have been extensively reported. Precise knowledge of the local anatomy and biomechanics is needed for correct selection of both levels and type of fixation when extending a fusion down to the sacrum. The use of iliac screws and anterior column support stabilizes the construct closer to the center of rotation of the lumbo-pelvic unit, reducing the load of posterior constructs. The authors review the different constructs for lumbosacral fusion, with special attention to their biomechanical rationale and clinical indications.