R. Beaujeux et al., POSTERIOR LUMBAR EPIDURAL FAT AS A FUNCTIONAL STRUCTURE - HISTOLOGIC SPECIFICITIES, Spine (Philadelphia, Pa. 1976), 22(11), 1997, pp. 1264-1268
Study Design. A topographic and histologic study was done to describe
the location of the lumbar epidural fat and to find potential tissular
specificities. Objectives. To search for possible histologic characte
ristics of posterior lumbar epidural fat, which so far has been descri
bed as semifluid tissue, and to determine whether posterior lumbar epi
dural fat is not simple incidental tissue. Summary of Background Data.
The lumbar epidural fat on two fetuses was studied. In adults, subcut
aneous fat and posterior lumbar epidural fat were taken from seven cor
pses. The authors obtained 13 posterior lumbar epidural fat pads (two
at L1-L2, three at L2-L3, six at L3-L4, and two at L4-L5) and four sub
cutaneous fat pads. Methods. The authors studied abdominal axial histo
logic sections in two fetuses, histologic multiplanar sections in seve
n adults, and semithin sections in four adults of posterior lumbar epi
dural fat and subcutaneous fat. Results. Fetal distribution of epidura
l fat was circumferential. Adult epidural fat distribution was limited
to the posterior part of the vertebral canal and located at the disc
level. Fascicles of connective tissue were less numerous and thinner i
n posterior lumbar epidural fat than in subcutaneous fat. Organized sl
iding spaces were found in the posterior epidural fat pad. Conclusions
. Posterior lumbar epidural fat is not a simple incidental tissue and
shows specific histologic features; sliding spaces and rarefaction of
connective tissue that could explain semifluid features of the tissue.
These characteristics suggest a functional role of posterior epidural
fat in the lumbar spinal unit.