Lumbosacral Transitional Vertebrae

Transcription

1 Lumbosacral Transitional Vertebrae Poster No.: C-073 Congress: ECR 206 Type: Educational Exhibit Authors: M. Mustapic, R. Vukojevi#, M. Gulin, D. Marjan, I. Boric ; 2 2 Zagreb/HR, Zabok/HR Keywords: Congenital, Diagnostic procedure, MR, Musculoskeletal spine DOI: 0.594/ecr206/C-073 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page of 22

2 Learning objectives Identification, classification, correct numbering and clinical relevance of the lumbosacral transitional vertebrae (LSTVs). Page 2 of 22

3 Background LSTVs are congenital spinal anomalies defined as either sacralization of the lowest lumbar segment or lumbarization of the most superior sacral segment of the spine. Complete transition results in numerical abnormalities, but in most cases transition is 2 incomplete or unilateral. 2 The prevalence of LSTV reported in the literature ranges from 4 to over 35%. Castellvi, et al. described a radiographic classification system identifying 4 types of LSTVs on the basis of morphologic characteristics 3,4 (Fig. and Table ). O'Driscoll, et al. developed a 4-type classification system of S-2 disc morphology by using sagittal MR images, depending on the presence or absence of disc material (Fig.2 and Table 2).,4,5 Not the classification, but the correct identification of LSTV and numbering of vertebrae seem to be the major problem. Inaccurate numbering may lead to an interventional procedure or surgery at an unintended level. Bertolotti syndrome, the association between an LSTV and low back pain, is still controversial since Bertolotti first described it in Several possible causes have been proposed : the pain may have discogenic origin, generated from the disc above LSTV due to hypermobility, while the disc below appears protected (Castellvi types II, III, IV); nerve roots may also be compressed between the transverse segment of the LSTV and the sacral ala (Castellvi type II); the pain may be generated in the pseudoarticulation between the enlarged transverse process and the sacral ala or ilium (Castellvi type II); patients with unilateral LSTV (Castellvi type IIa) may have contralateral facetogenic pain. Page 3 of 22

4 Images for this section: Fig. : Castellvi classification of LSTVs Konin GP, et al. Lumbosacral transitional vertebrae: classification, imaging findings, and clinical relevance. AJNR Am J Neuroradiol. 200 Nov;3(0): Page 4 of 22

5 Table : Castellvi classification of LSTVs Carrino JA, et al. Effect of spinal segment variants on numbering vertebral levels at lumbar MR imaging. Radiology. 20 Apr;259(): Fig. 2: O'Driscoll classification of the first sacral intervertebral disc morphology Konin GP, et al. Lumbosacral transitional vertebrae: classification, imaging findings, and clinical relevance. AJNR Am J Neuroradiol. 200 Nov;3(0): Page 5 of 22

6 Table 2: O'Driscoll classification of the first sacral intervertebral disc morphology Carrino JA, et al. Effect of spinal segment variants on numbering vertebral levels at lumbar MR imaging. Radiology. 20 Apr;259(): Page 6 of 22

7 Findings and procedure details Establishing whether an LSTV is a lumbarized S or a sacralized L5 can often be problematic, especially on MR images alone. Several numbering techniques have been suggested. Hahn et al. first described the use of the MR localizers to evaluate an LSTV instead of 6 the whole-spine MRI. Milicic et al. proposed MRI of the sacrococcygeal region and counting the vertebrae from 7 S5 upwards (Fig. 3 and 4). The other suggested techniques used to correctly number an LSTV are locating the iliolumbar ligaments 4,8 9 9, the position of the aortic bifurcation, the right renal artery or the 9 conus medullaris as the landmarks (Fig. 5-9). Hughes et al. reported the iliolumbar ligaments as a reliable marker to determine the L5 8 vertebral level on MRI but Carrino et al. showed in their study that iliolumbar ligaments always arose from the lowest mobile vertebra, from the L5 transverse process in nearly 4 97% of subjects. The other anatomic markers are widely believed to be less than satisfactory (the aortic bifurcation at the L4 vertebra in 67-83%, the right renal artery at the L-L2 intervertebral 9 disc in 75-92%, and the conus medullaris at the L vertebra in 56%). 0 Young et al. proposed a few numbering techniques using plain radiographs. The lumbar vertebra with the longest transverse process on the frontal view is regarded as L3 (92%), the level of iliac crest is regarded as between the L4 and L5 (98%), horizontally oriented lumbar vertebra on the lateral view is regarded as L4 (59%) and the level with 0 the largest sagittal plane angulation is regarded as between the L5 and S (93%). Only radiographs of the entire spine allow the radiologist to count from C2 inferiorly and to differentiate hypoplastic ribs from lumbar transverse processes and correct identification of the L vertebral body. But, it is rare to have radiographs of the entire spine. Page 7 of 22

8 Regarding the patients with LSTV and low back pain MRI is a method of choice. It usually revals the disc degeneration or herniation above LSTV (Fig. 0), the impingement due to enlarged transverse process (Fig. ) or contralateral facet joint degeneration (Fig. 2). Page 8 of 22

9 Images for this section: Fig. 3: MRI of sacrococcygeal region which allows counting the vertebrae from S5 upwards. Department of diagnostic and interventional radiology, University hospital centre, Sestre milosrdnice - Zagreb/HR Page 9 of 22

10 Fig. 4: MRI of sacrococcygeal region which allows counting the vertebrae from S5 upwards. Department of diagnostic and interventional radiology, University hospital centre, Sestre milosrdnice - Zagreb/HR Page 0 of 22

11 Fig. 5: Axial T2-WI at the level of the iliolumbar ligaments. Konin GP, et al. Lumbosacral transitional vertebrae: classification, imaging findings, and clinical relevance. AJNR Am J Neuroradiol. 200 Nov;3(0): Page of 22

12 Fig. 6: Coronal T-WI shows an LSTV (Castellvi IIa) and the iliolumbar ligaments. Department of diagnostic and interventional radiology, University hospital centre, Sestre milosrdnice - Zagreb/HR Page 2 of 22

13 Fig. 7: Axial T2-WI at the level of the aortic bifurcation. Department of diagnostic and interventional radiology, University hospital centre, Sestre milosrdnice - Zagreb/HR Page 3 of 22

14 Fig. 8: Sagittal T2-WI shows the position of the right renal artery at the L-L2 disc level. Department of diagnostic and interventional radiology, University hospital centre, Sestre milosrdnice - Zagreb/HR Page 4 of 22

15 Fig. 9: The sagittal T-WI shows conus medullaris at the level of L vertebral body. Department of diagnostic and interventional radiology, University hospital centre, Sestre milosrdnice - Zagreb/HR Page 5 of 22

16 Fig. 0: The disc herniation above the LSTV (O'Driscoll type 3). Bron JL, et al. The clinical significance of lumbosacral transitional anomalies. Acta Orthop Belg Dec;73(6): Page 6 of 22

17 Fig. : Semicoronal fat sat PD-WI shows enlarged left transverse process impinging the sacral ala (Castellvi type IIa). Department of diagnostic and interventional radiology, University hospital centre, Sestre milosrdnice - Zagreb/HR Page 7 of 22

18 Fig. 2: The contralateral facet joint degeneration. Konin GP, et al. Lumbosacral transitional vertebrae: classification, imaging findings, and clinical relevance. AJNR Am J Neuroradiol. 200 Nov;3(0): Page 8 of 22

19 Conclusion LSTVs are common anomalies of the spine and understanding of biomechanical alterations within the spine caused by transitional vertebra can aid the radiologist in recognizing the imaging findings in patients with LSTV and low back pain. Essentially, without high-quality imaging of the entire spine, there is no foolproof method for accurately numbering an LSTV. Therefore, identification of LSTV, correlation of intraoperative and preoperative imaging, and communication with the referring clinician, in order to avoid an interventional procedure or surgery at an unintended level, seem to be crucial. Page 9 of 22

20 Personal information Matej Mustapic, MD, PhD Rudolf Vukojevic, MD Matko Gulin, MD Domagoj Marjan, MD Igor Boric, MD, PhD, Ass. Prof. 2 University Hospital Centre Sisters of Mercy, Zagreb, Croatia 2 Special Hospital St. Catherine, Zabok, Croatia Page 20 of 22

21 References Konin GP, et al. Lumbosacral transitional vertebrae: classification, imaging findings, and clinical relevance. AJNR Am J Neuroradiol. 200 Nov;3(0): Bron JL, et al. The clinical significance of lumbosacral transitional anomalies. Acta Orthop Belg Dec;73(6): Castellvi AE, et al. Lumbosacral transitional vertebrae and their relationship with lumbar extradural defects. Spine (Phila Pa 976). 984 Jul-Aug;9(5): Carrino JA, et al. Effect of spinal segment variants on numbering vertebral levels at lumbar MR imaging. Radiology. 20 Apr;259(): O'Driscoll CM, et al. Variations in morphology of the lumbosacral junction on sagittal MRI: correlation with plain radiography. Skeletal Radiol. 996 Apr;25(3): Hahn PY, et al. Verification of lumbosacral segments on MR images: identification of transitional vertebrae. Radiology. 992 Feb;82(2): Milicic G, et al. Using magnetic resonance imaging to identify the lumbosacral segment in children. Coll Antropol Mar;30(): Hughes RJ, et al. Numbering of lumbosacral transitional vertebrae on MRI: role of the iliolumbar ligaments. AJR Am J Roentgenol Jul;87():W Lee CH, et al. Using MRI to evaluate anatomic significance of aortic bifurcation, right renal artery, and conus medullaris when locating lumbar vertebral segments. AJR Am J Roentgenol May;82(5): Hwang YJ, et al. Accuracy of the Criteria for Numbering of Lumbar Vertebrae on Plain Radiograph. American Society of Spine Radiology Symposium; March 20. Page 2 of 22

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