Possible rethetering. There are postoperative findings related to dethetering of the filum terminale and debulking of a lipomatous mass in the posterior lower lumbar spine with a surgical cavity or pseudomeningocele via L4 and L5 laminectomy. The previously demonstrated component of the lipomatous mass in the anterior spinal canal is no longer evident, aside from minimal epidural lipomatosis. However, the conus medullaris remains low lying, being positioned at the L4 vertebral body level. There is also clumping and posterior displacement of the cauda equina nerve roots, slightly eccentric to the left. There is a persistent left pars defect at L5. The lumbar spine vertebral alignment is unchanged. There is no significant spinal canal stenosis. There is mild bilateral facet joint hypertrophy with slight neural foramen stenosis at L4-L5 and what appears to be an associated 3 mm diameter posterior synovial cyst on the left side. There is scar tissue in the lower lumbar spine posterior subcutaneous tissues.
1. Interval evolution of postoperative findings related to dethetering of the filum terminale with persistent lipomatous malformation in the posterior lower lumbar spine associated with low-lying conus medullaris and clumping of the cauda equina, suggestive of persistent tethering.2. Left L5 pars defect.3. Mild bilateral facet joint degenerative changes with slight neural foramen stenosis at L4-L5.