• 1. Hakozaki T, Iwata M, Kanno N, et al. Cervical intervertebral disk herniation in chondrodystrophoid and nonchondrodystrophoid small-breed dogs: 187 cases (1993–2013). J Am Vet Med Assoc 2015;247:14081411.

    • Search Google Scholar
    • Export Citation
  • 2. Naudé SH, Lambrechts NE, Wagner WM, et al. Association of preoperative magnetic resonance imaging findings with surgical features in Dachshunds with thoracolumbar intervertebral disk extrusion. J Am Vet Med Assoc 2008;232:702708.

    • Search Google Scholar
    • Export Citation
  • 3. Jeffery ND, Levine JM, Olby NJ, et al. Intervertebral disk degeneration in dogs: consequences, diagnosis, treatment, and future directions. J Vet Intern Med 2013;27:13181333.

    • Search Google Scholar
    • Export Citation
  • 4. Levine JM, Fingeroth JM. Historical and current nomenclature associated with intervertebral disc pathology. In: Fingeroth JM, Thomas WB, eds. Advances in intervertebral disc disease in dogs and cats. Ames, Iowa: John Wiley & Sons Inc, 2015;2531.

    • Search Google Scholar
    • Export Citation
  • 5. Kazakos G, Polizopoulou ZS, Patsikas MN, et al. Duration and severity of clinical signs as prognostic indicators in 30 dogs with thoracolumbar disk disease after surgical decompression. J Vet Med A Physiol Pathol Clin Med 2005;52:147152.

    • Search Google Scholar
    • Export Citation
  • 6. Ryan TM, Platt SR, Llabres-Diaz FJ, et al. Detection of spinal cord compression in dogs with cervical intervertebral disc disease by magnetic resonance imaging. Vet Rec 2008;163:1115.

    • Search Google Scholar
    • Export Citation
  • 7. Cooper JJ, Young BD, Griffin JF, et al. Comparison between noncontrast computed tomography and magnetic resonance imaging for detection and characterization of thoracolumbar myelopathy caused by intervertebral disk herniation in dogs. Vet Radiol Ultrasound 2014;55:182189.

    • Search Google Scholar
    • Export Citation
  • 8. Bos AS, Brisson BA, Nykamp SG, et al. Accuracy, intermethod agreement, and inter-reviewer agreement for use of magnetic resonance imaging and myelography in small-breed dogs with naturally occurring first-time intervertebral disk extrusion. J Am Vet Med Assoc 2012;240:969977.

    • Search Google Scholar
    • Export Citation
  • 9. Besalti O, Pekcan Z, Sirin YS, et al. Magnetic resonance imaging findings in dogs with thoracolumbar intervertebral disk disease: 69 cases (1997–2005). J Am Vet Med Assoc 2006;228:902908.

    • Search Google Scholar
    • Export Citation
  • 10. Jeffery ND, Harcourt-Brown TR, Barker AK, et al. Choices and decisions in decompressive surgery for thoracolumbar intervertebral disk herniation. Vet Clin North Am Small Anim Pract 2018;48:169186.

    • Search Google Scholar
    • Export Citation
  • 11. Roach WJ, Thomas M, Weh JM, et al. Residual herniated disc material following hemilaminectomy in chondrodystrophic dogs with thoracolumbar intervertebral disc disease. Vet Comp Orthop Traumatol 2012;25:109115.

    • Search Google Scholar
    • Export Citation
  • 12. Svensson G, Simonsson US, Danielsson F, et al. Residual spinal cord compression following hemilaminectomy and minihemilaminectomy in dogs: a prospective randomized study. Front Vet Sci 2017;4:42.

    • Search Google Scholar
    • Export Citation
  • 13. Levine JM, Levine GJ, Johnson SI, et al. Evaluation of the success of medical management for presumptive cervical intervertebral disk herniation in dogs. Vet Surg 2007;36:492499.

    • Search Google Scholar
    • Export Citation
  • 14. Levine JM, Levine GJ, Johnson SI, et al. Evaluation of the success of medical management for presumptive thoracolumbar intervertebral disk herniation in dogs. Vet Surg 2007;36:482491.

    • Search Google Scholar
    • Export Citation
  • 15. Hettlich BF, Kerwin SC, Levine JM. Early reherniation of disk material in eleven dogs with surgically treated thoracolumbar intervertebral disk extrusion. Vet Surg 2012;41:215220.

    • Search Google Scholar
    • Export Citation
  • 16. Rossmeisl JH Jr, White C, Pancotto TE, et al. Acute adverse events associated with ventral slot decompression in 546 dogs with cervical intervertebral disc disease. Vet Surg 2013;42:795806.

    • Search Google Scholar
    • Export Citation
  • 17. Forterre F, Gorgas D, Dickomeit M, et al. Incidence of spinal compressive lesions in chondrodystrophic dogs with abnormal recovery after hemilaminectomy for treatment of thoracolumbar disc disease: a prospective magnetic resonance imaging study. Vet Surg 2010;39:165172.

    • Search Google Scholar
    • Export Citation
  • 18. Böttcher P, Böttcher IC, Ludewing E. Effect of ventral slot procedure on spinal cord compression in dogs with single static intervertebral disc disease: preliminary findings while evaluating a semiquantitative computed tomographic myelographic score of spinal cord compression. Vet Surg 2013;42:383391.

    • Search Google Scholar
    • Export Citation
  • 19. Huska JL, Gaitero L, Brisson BA, et al. Presence of residual material following mini-hemilaminectomy in dogs with thoracolumbar intervertebral disc extrusion. Can Vet J 2014;55:975980.

    • Search Google Scholar
    • Export Citation
  • 20. Salger F, Ziegler L, Böttcher IC. Neurologic outcome after thoracolumbar partial lateral corpectomy for intervertebral disc disease in 72 dogs. Vet Surg 2014;43:581588.

    • Search Google Scholar
    • Export Citation
  • 21. Laflamme DRPC. Development and validation of a body condition score system for dogs. Canine Pract 1997;22(1):1015.

  • 22. Martínez S, Fajardo R, Valdés J, et al. Histopathologic study of long-bone growth plates confirms the basset hound as an osteochondrodysplastic breed. Can J Vet Res 2007;71:6669.

    • Search Google Scholar
    • Export Citation
  • 23. Levine JM, Fosgate GT, Chen AV, et al. Magnetic resonance imaging in dogs with neurologic impairment due to acute thoracic and lumbar intervertebral disk herniation. J Vet Intern Med 2009;23:12201226.

    • Search Google Scholar
    • Export Citation
  • 24. Bergknut N, Auriemma E, Wijsman S, et al. Evaluation of intervertebral disk degeneration in chondrodystrophic and nonchondrodystrophic dogs by use of Pfirrmann grading of images obtained with low-field magnetic resonance imaging. Am J Vet Res 2011;72:893898.

    • Search Google Scholar
    • Export Citation
  • 25. Kranenburg HJ, Grinwis GC, Bergknut N, et al. Intervertebral disc disease in dogs—part 2: comparison of clinical, magnetic resonance imaging, and histological findings in 74 surgically treated dogs. Vet J 2013;195:164171.

    • Search Google Scholar
    • Export Citation
  • 26. Smolders LA, Bergknut N, Grinwis GC, et al. Intervertebral disc degeneration in the dog. Part 2: chondrodystrophic and non-chondrodystrophic breeds. Vet J 2013;195:292299.

    • Search Google Scholar
    • Export Citation
  • 27. Pfirrmann CW, Metzdorf A, Zanetti M, et al. Magnetic resonance classification of lumbar intervertebral disc degeneration. Spine (Phila Pa 1976) 2001;26:18731878.

    • Search Google Scholar
    • Export Citation
  • 28. Besalti O, Ozak A, Pekcan Z, et al. The role of extruded disk material in thoracolumbar intervertebral disk disease: a retrospective study in 40 dogs. Can Vet J 2005;46:814820.

    • Search Google Scholar
    • Export Citation
  • 29. Beltran E, Dennis R, Doyle V, et al. Clinical and magnetic resonance imaging features of canine compressive cervical myelopathy with suspected hydrated nucleus pulposus extrusion. J Small Anim Pract 2012;53:101107.

    • Search Google Scholar
    • Export Citation
  • 30. Sharp NJH, Wheeler SJ. Cervical disc disease. In: Sharp NJH, Wheeler SJ, eds. Small spinal disorders: diagnosis and surgery. Philadelphia: Elsevier Ltd, 2005;92120.

    • Search Google Scholar
    • Export Citation
  • 31. Sharp NJH, Wheeler SJ. Thoracolumbar disc disease. In: Sharp NJH, Wheeler SJ, eds. Small animal spinal disorders: diagnosis and surgery. Philadelphia: Elsevier Ltd, 2005;121159.

    • Search Google Scholar
    • Export Citation
  • 32. Aikawa T, Fujita H, Shibata M, et al. Recurrent thoracolumbar intervertebral disc extrusion after hemilaminectomy and concomitant prophylactic fenestration in 662 chondrodystrophic dogs. Vet Surg 2012;41:381390.

    • Search Google Scholar
    • Export Citation
  • 33. Forterre F, Konar M, Spreng D, et al. Influence of intervertebral disc fenestration at the herniation site in association with hemilaminectomy on recurrence in chondrodystrophic dogs with thoracolumbar disc disease: a prospective MRI study. Vet Surg 2008;37:399405.

    • Search Google Scholar
    • Export Citation
  • 34. Penning V, Platt SR, Dennis R, et al. Association of spinal cord compression seen on magnetic resonance imaging with clinical outcome in 67 dogs with thoracolumbar intervertebral disc extrusion. J Small Anim Pract 2006;47:644650.

    • Search Google Scholar
    • Export Citation
  • 35. Dhupa S, Glickman N, Waters DJ. Reoperative neurosurgery in dogs with thoracolumbar disc disease. Vet Surg 1999;28:421428.

  • 36. Cherrone KL, Dewey CW, Coates JR, et al. A retrospective comparison of cervical intervertebral disk disease in non-chondrodystrophic large dogs versus small dogs. J Am Anim Hosp Assoc 2004;40:316320.

    • Search Google Scholar
    • Export Citation
  • 37. Ingram EA, Kale DC, Balfour RJ. Hemilaminectomy for thoracolumbar Hansen Type I intervertebral disk disease in ambulatory dogs with or without neurologic deficits: 39 cases (2008–2010). Vet Surg 2013;42:924931.

    • Search Google Scholar
    • Export Citation
  • 38. De Risio L, Adams V, Dennis R, et al. Association of clinical and magnetic resonance imaging findings with outcome in dogs with presumptive acute noncompressive nucleus pulposus extrusion: 42 cases (2000–2007). J Am Vet Med Assoc 2009;234:495504.

    • Search Google Scholar
    • Export Citation
  • 39. Henke D, Gorgas D, Flegel T, et al. Magnetic resonance imaging findings in dogs with traumatic intervertebral disk extrusion with or without spinal cord compression: 31 cases (2006–2010). J Am Vet Med Assoc 2013;242:217222.

    • Search Google Scholar
    • Export Citation
  • 40. Maubon AJ, Ferru JM, Berger V, et al. Effect of field strength on MR images: comparison of the same subject at 0.5, 1.0, and 1.5 T. Radiographics 1999;19:10571067.

    • Search Google Scholar
    • Export Citation
  • 41. Magee T, Shapiro M, Williams D. Comparison of high-field-strength versus low-field-strength MRI of the shoulder. AJR Am J Roentgenol 2003;181:12111215.

    • Search Google Scholar
    • Export Citation
  • 42. Przeworski A, Adamiak Z, Głodek J. Comparison of high-field and low-field magnetic resonance imaging of stifle joint disorders in dogs. Pol J Vet Sci 2016;19:663670.

    • Search Google Scholar
    • Export Citation

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Agreement of surgeon's perception of the effectiveness of spinal cord decompression with findings on postoperative magnetic resonance imaging for dogs surgically treated for intervertebral disk extrusion

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  • 1 1Clinica Neurologica Veterinaria NVA, Via Isaac Newton 14, 20148 Milan, Italy.
  • | 2 2Research Centre on Public Health, Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy.
  • | 3 3Department of Health, Animal Science and Food Safety, University of Milan, 20133 Milan, Italy.

Abstract

OBJECTIVE

To determine the accuracy of the surgeon's perception versus postoperative MRI findings in assessing the effectiveness of spinal cord decompression achieved in dogs surgically treated for intervertebral disk extrusion (IVDE) and whether postoperative MRI findings were more likely to be associated with various outcomes.

ANIMALS

68 dogs surgically treated for cervical or thoracolumbar IVDE.

PROCEDURES

Data on clinical, neurologic, pre- and postoperative MRI, and intraoperative findings as well as outcomes and recovery times (6-month follow-up period) were prospectively collected and compared between various groups.

RESULTS

54 (79%) dogs had thoracolumbar IVDE, and 14 (21%) had cervical IVDE. Median degree of spinal cord compression as assessed on transverse T2-weighted MRI images was 45.6% before surgery and 8.8% after surgery. The correlation between surgeons' perception (n = 3) and postoperative MRI findings for the degree of spinal cord decompression achieved was only fair (κ = 0.40). Unsatisfactory spinal cord decompression as assessed via postoperative MRI was associated with severity of preoperative neurologic grade and preoperative compression, thoracolumbar (vs cervical) IVDE, and ventral (vs ventrolateral or dorsolateral) circumferential distribution of extruded material. Satisfactory (vs unsatisfactory) decompression as assessed via MRI was associated with a lower postoperative neurologic grade, greater likelihood of a successful outcome, and lower mean recovery time.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that for dogs surgically treated for IVDE, the surgeon's perception of adequate spinal cord decompression may be less reliable than postoperative MRI findings. Postoperative MRI appeared particularly useful for dogs with a severe preoperative neurologic status, severe preoperative spinal cord compression, and thoracolumbar IVDE.

Abstract

OBJECTIVE

To determine the accuracy of the surgeon's perception versus postoperative MRI findings in assessing the effectiveness of spinal cord decompression achieved in dogs surgically treated for intervertebral disk extrusion (IVDE) and whether postoperative MRI findings were more likely to be associated with various outcomes.

ANIMALS

68 dogs surgically treated for cervical or thoracolumbar IVDE.

PROCEDURES

Data on clinical, neurologic, pre- and postoperative MRI, and intraoperative findings as well as outcomes and recovery times (6-month follow-up period) were prospectively collected and compared between various groups.

RESULTS

54 (79%) dogs had thoracolumbar IVDE, and 14 (21%) had cervical IVDE. Median degree of spinal cord compression as assessed on transverse T2-weighted MRI images was 45.6% before surgery and 8.8% after surgery. The correlation between surgeons' perception (n = 3) and postoperative MRI findings for the degree of spinal cord decompression achieved was only fair (κ = 0.40). Unsatisfactory spinal cord decompression as assessed via postoperative MRI was associated with severity of preoperative neurologic grade and preoperative compression, thoracolumbar (vs cervical) IVDE, and ventral (vs ventrolateral or dorsolateral) circumferential distribution of extruded material. Satisfactory (vs unsatisfactory) decompression as assessed via MRI was associated with a lower postoperative neurologic grade, greater likelihood of a successful outcome, and lower mean recovery time.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that for dogs surgically treated for IVDE, the surgeon's perception of adequate spinal cord decompression may be less reliable than postoperative MRI findings. Postoperative MRI appeared particularly useful for dogs with a severe preoperative neurologic status, severe preoperative spinal cord compression, and thoracolumbar IVDE.

Contributor Notes

Address correspondence to Dr. Tirrito (federica.tirrito@nvamilano.it).