Page 778 - Clinical Small Animal Internal Medicine

746 Section 8 Neurologic Disease

Cellular Transplantation Therapy Intraspinal olfactory SCI is or is not beneficial for neurologic recovery remains
VetBooks.ir glial cell transplantation in dogs with thoracolumbar incompletely answered. Cord compression can be due to
displaced vertebral fragments, herniated intervertebral
SCI has been shown to have promise with respect to
improved functional outcome. The rationale for this
realignment of vertebrae alone; a laminectomy or hemi-
approach stems from the unique ability of these cells to disk or hematomas. Decompression may be achieved by
promote regeneration in experimentally induced injured laminectomy may be necessary to remove material from
spinal cord and foster a more hospitable environment for the vertebral canal. Decompressive procedures could
axonal growth, increase tissue sparing after SCI, increase produce or exacerbate instability in the injured spine,
tissue bridging and reduce cavity formation following thus requiring surgical stabilization.
experimental SCI, and improve angiogenesis within Instability can be addressed surgically, by placement
the injured spinal cord. Olfactory ensheathing glia can of an external splint, or simply by cage rest (Table 69.2).
be harvested from the olfactory epithelium and trans- Surgical stabilization is the most effective method of
planted in the same animal, thereby minimizing the like- stabilizing an unstable spine, but is associated with sig-
lihood of rejection. Autologous bone marrow stromal nificant surgical risks. A variety of different techniques
cell transplantation has been evaluated in dogs with ver- are used; in one of the most easily adaptable techniques,
tebral fracture luxation and found to be feasible and safe, screws or pins are placed in the vertebral bodies adja-
with no complications noted. cent to the injury and cement is applied to hold the
Although such techniques are currently in the early structure in alignment (Figure 69.7). Another popular
stages of development, they may represent the future for technique, sometimes known as “spinal stapling” or
patients with acute SCI. “segmental stabilization,” uses pins wired to articular
facets and dorsal spinous processes to stabilize dorsally.
Surgical Therapy Different plates can be used; difficulty contouring
A significant body of animal research has demonstrated plates to the vertebral bodies limits options, but more
neurologic benefit from early decompression of the recently locking plates such as the string of pearls (SOP)
injured spinal cord; however, such benefit is less clear in plate have been described which can offer more
polytrauma patients, who are often medically unstable in flexibility.
the acute postinjury phase. Despite the fact that early Sacrocaudal luxations in cats are typically addressed
spine surgery appears to be safe in polytrauma patients, by amputation of the tail if the tail is paralyzed and has
the question of whether early decompression for acute no nociception. Prompt removal of the tail may limit

Table 69.2 Advantages and disadvantages of different stabilization techniques

Technique Advantages Disadvantages Indications
Cage rest ● Inexpensive ● No stability provided ● Stable fracture (articular facet, dorsal
● No anesthetic or surgical risk ● No decompression spinous and transverse processes)
● No spinal cord compression
● Mild neurologic deficits
External splint ● Inexpensive ● Splint complications ● Unstable fracture
● No anesthetic or surgical risk ● Limited protection against ● Limited spinal cord compression
axial or rotational forces ● Mild neurologic deficits
● No decompression
Screws/pins and ● Excellent stabilization ● Cost ● Unstable fractures
PMMA; plates ● Can combine with ● Risk of iatrogenic injury
decompression during implant placement
● Infection
● Implant failure
Segmental ● Good stabilization against ● Suboptimal protection against ● Unstable lumbosacral/caudal lumbar
stabilization flexion and extension. rotational and axial forces fractures
● Reduced risk of iatrogenic ● Implant failure/migration
injury. ● Infection
● Readily applied in the
lumbosacral region
PMMA, polymethylmethacrylate cement.