Conus medullaris
The conus medullaris is the terminal end of the spinal cord.
Gross anatomy
After the cord terminates, the nerve roots descend within the spinal canal as individual rootlets, collectively termed the cauda equina. The conus medullaris most commonly terminates at the L1/2 intervertebral disc level in children and adults .
Extending from the conus is a delicate strand of fibrous tissue called the filum terminale that acts to give longitudinal support to the cord.
Variant anatomy
The termination of the conus medullaris has been reported from mid-T11 to mid-L3 vertebral body levels and the average termination varies from study-to-study but a level at or above the L2/3 intervertebral disc level can be considered normal and a level at L3 vertebral body is equivocal and can be a normal variant or the result of a tethered cord .