The axial transsacral approach to interbody fusion at L5-S1.
Lumbosacral interbody fusion may be indicated to treat degenerative disc disease at L5-S1, instability or spondylolisthesis at that level, and severe neural foraminal stenosis resulting from loss of disc space height. In addition, L5-S1 interbody fusion may provide anterior support to a long posterior fusion construct and help offset the stresses experienced by the distal-most screws. There are 3 well-established techniques for L5-S1 interbody fusion: anterior lumbar interbody fusion, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion. Each of these has advantages and pitfalls. A more recently described axial transsacral technique, utilizing the presacral corridor, may represent a minimally invasive approach to obtaining lumbosacral interbody arthrodesis. Biomechanical studies demonstrate that the stiffness of the axial rod is comparable to existing fixation devices, suggesting that, biomechanically, it may be a good implant for obtaining lumbosacral interbody fusion. Clinical studies have demonstrated good early results with the use of the axial transsacral approach in obtaining lumbosacral interbody fusion for degenerative disc disease, spondylolisthesis, and below long posterior fusion constructs. The technique is exacting and complications can be major, including rectal perforation and fistula, loss of correction, and pseudarthrosis.