Laurie's Blogs.

I came across one paper on this topic, which led me to search for more papers… with the thought that it is nice to bring together a grouping of papers to help round out how we should put the information in to clinical context.  In other words, to improve the “Why do I care about this research?” factor.   So, here are two such papers that discuss cervical disc herniations and what to do and/or what is found following surgery.

Aikawa T, Miyazaki Y, Kihara S, Muyama H, Nishimura M. Cervical intervertebral disc disease in 307 small-breed dogs (2000-2021): Breed-characteristic features and disc-associated vertebral instability. Aust Vet J. 2024 May;102(5):274-281. 

Are you aware of the concept of intervertebral disc degeneration and associated instability?

A research group in Tokyo, Japan studied 307 client-owned dogs with Cervical-IVDD treated with spinal cord decompression with or without vertebral stabilization (2000-2021).  There were 222 (72.3%) and 77 (25.1%) were CD and NCD breeds, respectively.  

Chondrodystrophic dogs were Dachshund (n = 114), French Bulldog (n = 26), Beagle (n = 24), Shih Tzu (n = 20), Toy Poodle (n = 19), Pekingese (n = 15) and other CD breeds (n = 4).

Non-Chondrodystrophic dogs were Chihuahua (n = 25), Yorkshire Terrier (n = 10), Miniature Pinscher (n = 10), Pomeranian (n = 10), Maltese (n = 7) and other NCD breeds (n = 15).

Vertebral instabilities were diagnosed based on the survey radiographs with computed tomography/magnetic resonance imaging (n = 2), dynamic myelography (n = 29), intraoperative spinal manipulation (n = 11) or second surgery in dogs with persistent postoperative paraspinal pain (n = 3).  

Of these dogs, 295 (96.1%) recovered.  Older age and frequent vertebral stabilization were the associated factors of the NCD dogs. Male dogs, caudal discs affected and NCD-breed dogs were the risk factors for disc-associated vertebral instability. 

C-IVDD in small-breed dogs potentially has concurrent disc-associated vertebral instability.  The authors then concluded that vertebral stabilization is indicated for small-breed dogs with cervical disc-associated vertebral instability.

Kikuchi Y, Takahashi F, Toki M, Shimada M, Hara Y, Yamaguchi S. Vertebral fixation does not affect recovery or recurrence of cervical intervertebral disc herniation in small dogs (< 15 kg). J Am Vet Med Assoc. 2023 May 30;261(10):1501-1509. 

This next paper then answer the logical follow-up question, “Does vertebral fixation improve outcomes or recurrence in this patient population?”

Here, another Japanese research group investigated the outcome of 303 small dogs diagnosed with Cervical-IVDH (C-IVDH) and treated with ventral slot decompression surgery (VSD).

Removal of herniated disc material was completed, and  if no disc material remained around the slot, then the removal of disc material was judged to be sufficient, and the VSD was completed.  If the disc was extruded, after the removal of all disc materials, these dogs then also received vertebral fixation (VF).

Results?

VF did not affect recovery.  However, nonchondrodystrophic breeds had poorer recovery  than chondrodystrophic breeds.  A higher preoperative cervical myelopathy grade (grade 3 or 4) was associated with poorer recovery, compared with grade 1. VF did not affect recurrence); however, increasing age was associated with recurrence.

This group concluded that in small dogs with C-IVDH, even if the slot volume is increased to remove sufficient disc material during VSD, a good prognosis can be achieved with or without VF.  Furthermore, they noted that their results suggest that slot volume could be increased and VF could be applied in combination with VSD to sufficiently remove disc material in small dogs with C-IVDH without increasing risk for adjacent, recurrent C-IVDH.

Why do you care?

This is always a bit of a tricky part.  Sometimes I figure, ‘Ah well, this paper is just good-to-know, and other times, a paper challenges what I would do clinically in rehab practice.’   These papers are perhaps a wee bit of both!  Yes, the information is good to know.  What I take away clinically is that in dogs after a ventral slot procedure, there is some instability.  So, I should work to retrain stability in the neck.  Typically in humans this would be small movements that don’t engage the big mover muscles… so very small movements, and/or eye initiated movements (i.e. follow a cookie while still well within the visual field).  It might also mean that I could look to minimize overuse of the big muscles using fascial techniques to release trigger points and/or elongate those muscles perhaps using fascial blades or Gua sha tools.  Just things to think about.  Honestly, it’s the nerd in me that like to challenge my brain to come up with reasons to care about a study.  So, this is what I came up with.

What do you think?

Cheers,

Laurie