Summary
The polar recesses, superior and inferior to lumbar facet joints, are filled by fat pads from which fatfilled synovial folds project between the articular surfaces for a distance of two to four millimetres. The intracapsular superior recess lies between the ligamentum flavum and the lamina above. The extracapsular inferior recess lies on the back of the lamina below and communicates with the joint through a hole in the inferior capsule. The intracapsular folds move freely in and out of the joint during movements. These features are demonstrated in anatomic studies using transverse sections and radiologic studies using computed tomography. In about 4% of lumbar spines examined, the intraarticular fat pads are enlarged and extend from the joint recess(es) into the middle third of one or more facet joints. The fat pads can be identified in CT scans by their radiolucency and distinguished from vacuum phenomenon by measuring their attenuation values. The cause of the intra-articular enlargement of the fat pads is unknown, but it is suggested that their extension into the middle third of the joint may be secondary to degenerative change in the motion segment with capsular laxity in the affected joint.
Similar content being viewed by others
References
Warwick R, Williams PL (1973) Grays anatomy. Longmans, London, p 395
Lewin T et al. (1962) The morphology of the lumbar synovial Intervertebral joint. Acta Morphol Neerl Scand 4:299–319
Kos J (1969) Contribution a l'etude de l'anatomie et de la vascularisation des articulations intervertebraux. Bull Assoc Anat (Nancy) 142:1088–1104
Giles LGF, Taylor J (1982) Intra-articular protrusions in the lower lumbar apophyseal joints. Bull Hosp Jt Dis 42:248–254
Bogduk N, Engel R (1984) The menisci of the lumbar zygapophyseal joints. Spine 9:454–460
Taylor JR, Twomey LT (1986) Age changes in lumbar zygapophyseal joints: observations on structure and function. Spine 11: 739–745
McCormick CC, Taylor JR, Twomey LT (1989) Facet joint arthrography in lumbar spondylolysis: anatomic basis for spread of contrast. Radiology 171:193–196
McFadden KD, Taylor JR (1990) Gapping in lumbar zygapophyseal joints. Spine 15:295–299
Giles L, Taylor J (1983) Histological preparation of large vertebral specimens. Stain Technol 58:45–49
Taylor JR, McCormick CC, Willen J (1989) Lumbar zygapophyseal incongruity as a sign of motion segment instability. J Anat 165:299–300
Grenier N et al. (1987) Normal and degenerative posterior spinal structures. Radiology 165:517–525
Husson JL et al. (1987) True intra-articular lipoma of the lumbar spine. Spine 8:820–822
Dietemann JL et al. (1989) CT of lumbar apophyseal joint lipoma: report of 3 cases. Neuroradiology 31:60–62
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Taylor, J.R., McCormick, C.C. Lumbar facet joint fat pads: their normal anatomy and their appearance when enlarged. Neuroradiology 33, 38–42 (1991). https://doi.org/10.1007/BF00593331
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00593331