Lumbosacral foraminal ratios and areas using MRI in medium-sized dogs

D. Reynolds; R. L. Tucker; N. Fitzpatrick

doi:10.3415/VCOT-13-05-0085

Veterinary and Comparative Orthopaedics and Traumatology, Table of Contents

Vet Comp Orthop Traumatol 2014; 27(05): 333-338
DOI: 10.3415/VCOT-13-05-0085

Original Research

Schattauer GmbH

Lumbosacral foraminal ratios and areas using MRI in medium-sized dogs

D. Reynolds

¹Toronto Veterinary Emergency Hospital, Toronto, ON, Canada

,

R. L. Tucker

²Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA, USA

,

N. Fitzpatrick

³Fitzpatrick Referrals, Surrey, United Kingdom

› Author Affiliations

Abstract

Summary

Objective: To examine conventional magnetic resonance imaging planes of the lumbosacral foramina to obtain objective measurements of foraminal size in mediumsized (20–28 kg) normal dogs.

Method: Ten canine cadavers were evaluated using magnetic resonance imaging in neutral, flexed and extended position. Foraminal ratios, areas and lumbosacral angles were calculated and their relationship to body weight was evaluated.

Results: Foraminal ratios were found to be independent of body weight in medium sized dogs (p >0.42). Foraminal areas were dependent on body weight (p <0.05). Flexion and extension were shown to significantly change both the foraminal ratio and area.

Clinical significance: Lumbosacral foraminal stenosis is common in working dogs. Foraminal ratios were evaluated in mediumsized dogs and were found to be independent of body weight, which may provide objective evaluation of surgical decompression techniques if calculated pre- and post-surgery. Foraminal areas were not independent of body weight.

Keywords

Lumbosacral - foraminal stenosis - MRI - dogs

Full Text

References

References
1 Palmer RH, Chambers JN. Canine lumbosacral diseases. Part I. Anatomy, pathophysiology, and clinical presentation. Compendium of Continuing Education Practicing Veteterinarian 1991; 13: 61-68.
2 Adams WH, Daniel GB, Pardo AD. et al Magnetic resonance imaging of the caudal lumbar and lumbosacral spine in 13 dogs (1990-1993). Vet Radiol Ultrasound 1995; 36: 3-13.
3 De Haan JJ, Shelton SB, Ackerman N. Magnetic resonance imaging in the diagnosis of degenerative lumbosacral stenosis in four dogs. Vet Surg 1993; 22: 1-4.
4 Higgins BM, Cripps PJ, Baker M. et al Effects of body position, imaging plane, and observer on computed tomographic measurements of the lumbosacral intervertebral foraminal area in dogs. Am J Vet Res 2011; 72: 905-917.
5 Jones JC, Sorjonen DC, Simpson ST. et al Comparison between computed tomographic and surgical findings in nine large-breed dogs with lumbosacral stenosis. Vet Radiol Ultrasound 1996; 37: 247-256.
6 Jones JC, Shires PK, Inzana KD. et al Evaluation of canine lumbosacral stenosis using intravenous contrast enhanced computed tomography. Vet Radiol Ultrasound 1999; 40: 108-114.
7 Jones JC, Inzana KD. Subclincal CT abnormalities in the lumbosacral spine of older large-breed dogs. Vet Radiol Ultrasound 2000; 41: 19-26.
8 Jones CJ, Davies SE, Werre SR. et al Effects of body position and clinical signs on L7-S1 intervertebral foraminal area with lumbosacral disease as measured via computed tomography. Am J Vet Res 2008; 69: 1446-1454.
9 Lang J. Flexion-extension myelography of canine cauda equina syndrome. Vet Radiol Ultrasound 1998; 29: 242-257.
10 Mattoon JS, Koblik PD. Quantitative survey radiographic evaluation of the lumbosacral spine of normal dogs and dogs with degenerative lumbosacral stenosis. Vet Radiol Ultrasound 1993; 34: 194-206.
11 Ramirez O, Thrall DE. A review of imaging techniques for canine cauda equine syndrome. Vet Radiol Ultrasound 1998; 39: 283-296.
12 Suwankong N, Voorhout G, Hazelwinkel HAW. et al Agreement between computed tomography, magnetic resonance imaging, and surgical findings in dogs with degenerative lumboscral stenosis. J Am Vet Med Assoc 2006; 229: 1924-1929.
13 Mayhew PD, Kapatkin AS, Wortman JA. et al Association of cauda equina compression on magnetic resonance images and clinical signs in dogs with degenerative lumbosacral stenosis. J Am Anim Hosp Assoc 2002; 38: 555-562.
14 Speciale AC, Pietrobon R, Urban CW. et al Observer variability in assessing lumbar spinal stenosis severity on magnetic resonance imaging and its relation to cross-sectional spinal canal area. Spine 2002; 27: 1082-1086.
15 Rossi F, Seiler G, Busato A. et al Magnetic resonance imaging of articular process joint geometry and intervertebral disk degeneration in the caudal lumbar spine (L5-S1) of dogs with clinical signs of cauda equina compression. Vet Radiol Ultrasound 2004; 45: 381-387.
16 Boden SD, Mc Cowin PR, Davis DO. et al Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am 1990; 72: 403-408.
17 Borenstein DG, O’Mara JW, Boden SD. et al The value of magnetic resonance imaging of the lumbar spine to predict low-back pain in asymptomatic subjects. J Bone Joint Surg Am 2001; 83.: 1306-1311.
18 Godde T, Steffan F. Surgical treatment of lumbosacral foraminal stenosis using a lateral approach in twenty dogs with degenerative lumbosacral stenosis. Vet Surg 2007; 36: 705-713.
19 Jenis LG, An HS. Spine Update - Lumbosacral foraminal stenosis. Spine 2000; 25: 389-394.
20 Attias N, Hayman A, Hipp JA. et al Assessment of magnetic resonance imaging in the diagnosis of lumbar spine foraminal stenosis - A surgeon’s perspective. J Spinal Disord Tech 2006; 19: 249-256.
21 Hasegawa T, An HS, Haughton VM. et al (1995) Lumbar foraminal stenosis: critical heights of the intervertebral discs and foramina. A cryomicrotome study in cadavers. J Bone Joint Surg Am 1995; 77: 32-38.
22 Wildermuth S, Zanetti M, Duewell S. et al Lumbar spine: Quantitative and qualitative assessment of positional (upright flexion and extension) MR imaging and myelography. Radiology 1998; 207: 391-398.
23 Cramer GD, Cantu JA, Dorsett RD. et al Dimensions of the lumbar intervertebral foramina as determined from the sagittal plane magnetic resonance imaging scans of 95 normal subjects. J Manipulative Physiol Ther 2003; 26: 160-170.
24 Humphreys SC, Ab HS, Eck JC. et al Oblique MRI as a useful adjunct in evaluation of cervical foraminal impingement. J Spinal Disord 1998; 11: 295-299.
25 Tien RD, Buxton RB, Schwighoter BW. et al Quantitation of structural distortion of the cervical neural foramina in gradient-echo MR imaging. J Magn Reson Imaging 1991; 1: 683-687.
26 Wood BC, Lanz OI, Jones JC. et al Endoscopic-assisted lumbosacral foraminotomy in the dog. Vet Surg 2004; 33: 221-231.
27 Jones JC, Wright JC, Bartels JE. Computed tomographic morphometry of the lumbosacral spine of dogs. Am J Vet Res 1995; 56: 1125-1132.
28 Yoo JU, Zou D, Edwards WT. et al Effect of cervica-spine motion on the neuroforaminal dimensions of human cervical-spine. Spine 1992; 17: 1131-1136.
29 Bagley RS. Surgical stabilization of the lumbosacral joint. In Slatter DH. editor Textbook of Small Animal Surgery. 3rd ed. Philadelphia: WB Saunders; 2002: 1238-1243.
30 Inufusa A, An HS, Hasegawa T. et al. Anatomic changes of the spinal canal and intervertebral foramen associated with flexion-extension movement. Spine 1996; 21: 2412-2420.