Abstract
Introduction
Symptomatic foraminal stenosis has been observed in patients with degenerative disc disease, scoliosis, asymmetrical disc degeneration and spondylolisthesis. Nevertheless not all patients with the above pathologies will develop symptomatic foraminal stenosis. We hypothesised that symptomatic patients have anatomical predisposition to foraminal stenosis, namely a larger pedicle height (PH) to vertebral body height (VH) ratio, leaving less room below the pedicle for the exiting nerve root compared to asymptomatic patients.
Patient sample
66 Patients were divided in two groups. The surgical group consisted of 37 patients (average age of 61 years) who presented with severe radicular symptoms resisting to conservative measures and requiring decompression and transforaminal lumbar interbody fusion (TLIF). The control group consisted of 29 patients (average age of 51 years) presenting with low back pain (LBP) but with no radicular symptoms and who were treated conservatively.
Methods
We measured VH at the level of the posterior wall as well as PH on parasagittal images (CT or MRI) on all lumbar levels (L1 to L5). Statistical analysis was performed using Student’s t test.
Results
No difference in PH was found between the two groups for L1 to L4 levels. By contrast, there was a highly statistically significant difference in VH between the two groups from L1 to L4 level. In the surgical group, the VH was smaller (p < 0.001).
Conclusions
Symptomatic patients with foraminal stenosis have smaller VH leading to lesser space beneath the pedicle and putting the exiting nerve root at risk in cases of spondylolisthesis or disc degeneration.
Similar content being viewed by others
References
Simmons EH, Jackson RP (1979) The management of nerve root entrapment syndromes associated with the collapsing scoliosis of idiopathic lumbar and thoracolumbar curves. Spine 4:533–541
Hasegawa T, An HS, Haughton VM, Nowicki BH (1995) Lumbar foraminal stenosis: critical heights of the intervertebral discs and foramina. A cryomicrotome study in cadavera. J Bone Joint Surg Am 77:32–38
Torun F, Dolgun H, Tuna H, Attar A, Uz A, Erdem A (2006) Morphometric analysis of the roots and neural foramina of the lumbar vertebrae. Surgical neurology 66:148–151. doi:10.1016/j.surneu.2006.02.041 (Discussion 151)
Kaneko Y, Matsumoto M, Takaishi H, Nishiwaki Y, Momoshima S, Toyama Y (2012) Morphometric analysis of the lumbar intervertebral foramen in patients with degenerative lumbar scoliosis by multidetector-row computed tomography. Eur Spine J 21:2594–2602. doi:10.1007/s00586-012-2408-7
Cinotti G, De Santis P, Nofroni I, Postacchini F (2002) Stenosis of lumbar intervertebral foramen: anatomic study on predisposing factors. Spine 27:223–229
Schulte TL, Heidenreich JO, Schilling AM, Stendel R, Pietila TA, Hopfenmuller W, Brock M, Wolf KJ (2004) Comparison of metric analysis of spinal structures, exemplarily of the ligamentum flavum, obtained with CT and MRI. Eur J Radiol 52:224–228. doi:10.1016/j.ejrad.2003.11.022
Gilsanz V, Loro ML, Roe TF, Sayre J, Gilsanz R, Schulz EE (1995) Vertebral size in elderly women with osteoporosis. Mechanical implications and relationship to fractures. J Clin Investig 95:2332–2337. doi:10.1172/JCI117925
Ferrar L, Roux C, Reid DM, Felsenberg D, Gluer CC, Eastell R (2012) Prevalence of non-fracture short vertebral height is similar in premenopausal and postmenopausal women: the osteoporosis and ultrasound study. Osteoporos Int 23:1035–1040. doi:10.1007/s00198-011-1657-3
Torun F, Tuna H, Buyukmumcu M, Caglar S, Baysefer A (2008) The lumbar roots and pedicles: a morphometric analysis and anatomical features. J Clin Neurosci 15:895–899. doi:10.1016/j.jocn.2007.08.006
Jenis LG, An HS (2000) Spine update. Lumbar foraminal stenosis. Spine 25:389–394
Nowicki BH, Haughton VM, Schmidt TA, Lim TH, An HS, Riley LH 3rd, Yu L, Hong JW (1996) Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading. AJNR Am J Neuroradiol 17:1605–1614
Fu KM, Rhagavan P, Shaffrey CI, Chernavvsky DR, Smith JS (2011) Prevalence, severity, and impact of foraminal and canal stenosis among adults with degenerative scoliosis. Neurosurgery 69:1181–1187. doi:10.1227/NEU.0b013e31822a9aeb
Fujiwara A, An HS, Lim TH, Haughton VM (2001) Morphologic changes in the lumbar intervertebral foramen due to flexion-extension, lateral bending, and axial rotation: an in vitro anatomic and biomechanical study. Spine 26:876–882
Schizas C, Theumann N, Burn A, Tansey R, Wardlaw D, Smith FW, Kulik G (2010) Qualitative grading of severity of lumbar spinal stenosis based on the morphology of the dural sac on magnetic resonance images. Spine 35:1919–1924. doi:10.1097/BRS.0b013e3181d359bd
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Merckaert, S., Pierzchala, K., Kulik, G. et al. Influence of anatomical variations on lumbar foraminal stenosis pathogenesis. Eur Spine J 24, 313–318 (2015). https://doi.org/10.1007/s00586-014-3524-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00586-014-3524-3