Abnormal L5-S1 Facet Joint Orientation as a Harbinger of Degenerative Spondylolisthesis: A Case Report

Abstract

Degenerative spondylolisthesis is a common cause of low back pain and resultant disability in the adult population. The causes of degenerative spondylolisthesis are not entirely understood, though a combination of anatomic and lifestyle factors likely contributes to the development of this pathology. Here, we report a case of a 38-year-old female presenting with low back pain and right lower extremity radiculopathy, found to have degenerative L5-S1 spondylolisthesis, which we postulate developed in part due to the sagittal orientation of her L5-S1 facet joints bilaterally.

Keywords: injury biomechanics; lumbar spine; neurosurgery; orthopedic surgery; spine surgery; spondylolisthesis; surgery; transforaminal lumbar interbody fusion.

Figure 1. Axial (left) and sagittal (right) T2-weighted MRI of the lumbar spine without contrast at the level of L5-S1, demonstrating severe central canal and lateral recess stenosis (red arrow) with bilateral foraminal stenosis, as well as facet joint effusions (blue arrows)

Figure 2. An axial (left) and sagittal (right) CT scan of the lumbar spine at the L5-S1 level

Note the pars defect on the right (red arrow), as well as the sagittal orientation of the L5-S1 facet joint line (blue lines).

Figure 3. A flexion (left) and extension (right) lateral plain film radiograph of the lumbar spine demonstrating a mobile spondylolisthesis at L5-S1 (red arrows)

Figure 4. A lateral (left) and anterior/posterior (right) lateral plain film radiograph of the lumbar spine after the placement of the L5-S1 interbody graft and percutaneous pedicle screw fixation, with reduction of the spondylolisthesis (red arrow) seen on the lateral film