48-year-old male with bilateral L5 radiculopathy. Five lumbar type vertebral bodies are presumed to be present. Since prior MR, posterior fusion has been extended to include the L4-S1 levels with iliac screws. Details are better appreciated on most recent CT on 12/13/2016. Interbody fusion device at the L5-S1 level and laminectomy at the L5 level are again noted. There are endplate changes involving the L5-S1 level, likely related to postoperative and degenerative changes. Vertebral body heights are otherwise well-maintained. There is 10 mm of anterior spondylolisthesis of L5 on S1, without significant interval change. Alignment is otherwise within normal limits. Bone marrow signal is benign. The conus medullaris is normal in position.There are fluid collections in the superficial and deep posterior soft tissues. In the deep posterior soft tissues, an irregular fluid collection extends from the L3-L4 level to the L5-S1 level and measures up to 6 cm in the craniocaudal dimension and 2.5 cm in thickness with enhancement of the surrounding soft tissues. More superficially, there is a larger fluid collection measuring up to 12 cm in the craniocaudal dimension and 2.5 cm in thickness. No epidural collection is identified.Multilevel degenerative changes are seen, as described below:L1-L2: No significant disc disease. No spinal canal or neural foraminal stenosis.L2-L3: No significant disc disease. No spinal canal or neural foraminal stenosis.L3-L4: No significant disc disease. No spinal canal or neural foraminal stenosis.L4-L5: Again seen is a mild disc bulge with small central protrusion. Mild neural foraminal stenosis, without significant interval change. No significant spinal canal stenosis. L5-S1: Grade 2 anterolisthesis of L5 on S1, without significant interval change. There are endplate changes, likely related to surgery and degeneration. Again seen is diffuse disc bulge and mild facet arthropathy causing mild spinal canal stenosis. Neural foraminal stenosis is suspected bilaterally but not well seen due to surrounding artifact.
1. Evidence of interval extension of posterior fusion, which now extends from the L4-S1 level and iliac bones.2. New fluid collections in the superficial and deep posterior operative soft tissues, which may be within normal limits given patient's recent surgery. Correlation with clinical and laboratory parameters is advised to assess for possibility of infection.3. Disc degeneration and facet arthropathy of the L5-S1 level causing mild spinal canal stenosis, similar to prior. Neural foraminal stenoses is suspected but not well seen due to artifact.