Causes include lipomatous lesions (intramedullary lipomas, lipomyelomeningoceles, lipoma of the filum terminale); myelomeningocele; diastematomyelia; and a short, thickened filum terminale (>2 mm).
Imaging Findings :Caudal displacement of the conus below the L2L3 level in neonates and young children or below the middle of L2 after age 12.
Tethered cord syndrome. Sagittal T1-weighted image in a patient who had undergone a myelomeningocele repair at birth shows that the cord ends at the L5 level (straight arrow). Note the absence of the posterior elements of the sacrum, as well as the presence of a high-signal-intensity mass (lipoma) within the sacral spinal canal (curved arrows).