Recurrent thoracolumbar intervertebral disc extrusion after hemilaminectomy and concomitant prophylactic fenestration in 662 chondrodystrophic dogs

Vet Surg. 2012 Apr;41(3):381-90. doi: 10.1111/j.1532-950X.2012.00970.x. Epub 2012 Mar 1.


Objectives: To determine the prevalence and location of recurrent thoracolumbar intervertebral disc extrusion (T-L IVDE) after hemilaminectomy with prophylactic fenestration (PF) and to document PF-related complications.

Study design: Retrospective case series.

Sample population: Chondrodystrophic dogs (n = 793).

Methods: In 662 successfully recovered dogs (>1 year follow-up), the prevalence of dogs with recurrent T-L IVDE that required a 2nd surgery and dogs with clinical signs that improved without surgery was evaluated. Prevalence of second disc extrusions (SDEs) within T11-L4 intervertebral discs was compared between PF discs and non-PF discs.

Results: T-L SDEs were intraoperatively confirmed in 15 dogs (2.3%), 2-61 months after initial surgery and 66 dogs (10.0%) had signs of T-L IVDE recurrence that improved without surgery (mean follow-up, 44.7 months). No dog had further extrusion at the initial T-L site. SDE occurred at a PF disc (n = 1), adjacent to PF discs (8), or at distant discs (6). Prevalence of SDE in non-PF discs was 26.2 times higher than PF discs (95% CI: 3.4, 203.4; P < .001). Major PF-related complications included iatrogenic introduction of the disc material into the spinal canal (n = 1), and vertebral subluxation/instability (3) at 1-88 months postoperatively.

Conclusion: SDE is more likely to occur at non-PF discs than PF discs when PF is performed at spaces predisposed to disc extrusion. PF is a safe and effective treatment to prevent SDE in chondrodystrophic dogs.

MeSH terms

  • Animals
  • Dog Diseases / pathology
  • Dog Diseases / surgery*
  • Dogs
  • Female
  • Intervertebral Disc Displacement / etiology
  • Intervertebral Disc Displacement / pathology
  • Intervertebral Disc Displacement / veterinary*
  • Laminectomy / adverse effects
  • Laminectomy / veterinary*
  • Magnetic Resonance Imaging / veterinary
  • Male
  • Osteochondrodysplasias / pathology
  • Osteochondrodysplasias / surgery
  • Osteochondrodysplasias / veterinary*
  • Recurrence
  • Retrospective Studies