Anterior transvertebral interbody cage with posterior transdiscal pedicle screw instrumentation for high-grade spondylolisthesis. Technical note.

Adult high-grade degenerative spondylolisthesis represents the extreme end of the spectrum for spondylolisthesis and is consequently rarely encountered. Surgical management of high-grade spondylolisthesis requires constructs capable of resisting the shear forces at the slipped L5-S1 interspace. The severity of the slip, sacral inclination, and slip angle may make conventional approaches to 360 degrees fusion difficult or hazardous. Transdiscal pedicle screw fixation, transvertebral fibular graft fusion, and transvertebral cage fixation are techniques that have been developed to establish anterior column load sharing and to resist shear forces at the L5-S1 interspace, given the anatomical constraints accompanying high-grade spondylolisthesis. In this technical note the authors describe the procedure for implanting an in situ anterior L5-S1 transvertebral cage and performing L4-5 anterior lumbar interbody fusion, followed by placement of posterior S1-L5 vertebral body transdiscal pedicle screws for management of high-grade spondylolisthesis.