Fig. 7

Levels used in the classification of the depth of the conus medullaris position with regard to vertebral segments: 1 - up to the D12L1 intervertebral disc; 2 - upper third of L1 vertebral body; 3 – middle third of L1 body; 4 – lower third of L1 body; 5 - L1L2 intervertebral disc; 6 - upper third of L2 body; 7 – middle third of L2 body; 8 – lower third of L2 body; 9 –lower than L2 body