Lateral extent and ventral laminar attachments of the lumbar ligamentum flavum: Cadaveric study

Background context Cadaveric descriptions of the deep layer of the lumbar ligamentum flavum (LF), extending between contiguous borders of adjacent laminae and into the lateral spinal canal region are limited.

Purpose To provide detailed descriptions of the lumbar LF.

Study design Cadaveric dissection.

Methods The deep ligamentum flava of 14 formalin-fixed human cadaver lumbar spines (140 levels) were examined to assess their laminar attachments and lateral extents in relation to the intervertebral foramen.

Results The variable attachment of the deep layer of the LF with respect to the cephalad and caudad laminae was identified and described. At each successive caudal level of the lumbar spine, the deep layer appeared to become a more prominent feature of the posterior vertebral column, lining more of the laminae to which it is attached and encroaching further into the posteroinferior region of the intervertebral foramen at its lateral margins.

Conclusions We describe our observations of the deep LF in the human lumbar spine. These observations have clinical relevance for the interpretation of radiologic imaging and the performance of adequate decompression in the setting of spinal stenosis.