Female, 57 years old, with bilateral lower extremity pain, numbness and possible weakness in the setting of prior surgery. Evidence of posterior instrumented fusion is seen with bilateral pedicle screws and stabilization rods spanning L5 and S1. Interbody devices have also been placed in the L5-S1 disc space.A very mild scoliotic curvature of the lumbar spine is seen. Sagittal alignment is within normal limits. Vertebral body height and morphology are unremarkable. Mild fatty endplate degenerative signal change is seen anteroinferiorly at L4. Elsewhere, marrow signal characteristics are within normal limits. No evidence of marrow edema is detected. No evidence of worrisome spinal or paraspinal enhancement is seen.The visualized distal spinal cord, conus and nerve roots of the cauda equina are within normal limits, except as discussed by level below.L1-2: Unremarkable. L2-3: Unremarkable. L3-4: Mild facet hypertrophy and ligamentum flavum thickening. Mild bulging disc. Left foraminal and far lateral disc protrusion which effaces the inferior aspect of the neural foramen. The exiting L3 nerve root does not appear to be significantly affected, but the protrusion does partially efface the left lateral recess and may contact the transiting L4 nerve root. No significant generalized spinal canal stenosis. No significant right foraminal narrowing. L4-5: Marked facet hypertrophy with ligamentum flavum thickening. Bulging disc. Moderate to severe generalized spinal canal stenosis with crowding of the cauda equina nerve roots. Moderate bilateral foraminal narrowing. L5-S1: Postoperative findings. No significant spinal canal stenosis. No significant foraminal narrowing suspected within the limitations of some artifactual distortion due to the orthopedic instruments. A small defect within the left iliac bone may represent a bone graft harvest site.
1.Postoperative findings compatible with instrumented posterior fusion from L5 to S1.2.Left foraminal and far lateral disc protrusion at L3-4 which narrows the neural foramen and effaces the left lateral recess. The transiting L4 nerve root may be affected by this process.3.Moderate to severe generalized spinal canal stenosis at L4-5 due to a combination of disc bulge and posterior element hypertrophy. Moderate foraminal narrowing is also evident at this level.4.Although the L5-S1 level is slightly degraded by artifact, no significant spinal canal or foraminal stenosis is suspected.