Epsilon Archive for Student Projects

Abstract

The cervical spine is normally subjected to a variety of forces and structured to remain stable under
these. However, instability of the cervical spine may occur due to several lesions and diseases in the
canine species, causing the affected individuals’ neurological deficits, damage, and subsequent pain.
Spinal fusion, the joining of two vertebrae, is a widely accepted method to relieve pain and stabilize
unstable segment and aid in neurological recovery. A variety of surgical techniques to achieve this
in canines have been described. Often, a material to promote bone formation is added to the surgical
site, autologous bone grafts being regarded as the gold standard. With today’s techniques and
materials, there is a large variability regarding outcome of the fusion. There is a need for alternative
materials that can increase success rate and predictability of development of fusion in both human
and veterinary medicine. Recently, a calcium phosphate ceramic with osteoinductive properties
showed clinical promise in cranioplasty in humans. The aim of the present study was to investigate
whether this ceramic material would promote/enable bone fusion in the cervical spine of a porcine
model. Three pigs underwent surgery and received two intervertebral lesions in the cervical spine,
one with the implant and one without. Computed tomography scans were performed pre-surgery,
immediately post-surgery and three-month post-surgery. Each cervical intervertebral disc space was
measured, and each segment of the cervical spine evaluated regarding grade of fusion, grade and
localization of sclerosis, lysis and bone formation. At the three-month post-surgery scan, disc spaces
at the site of the implant were generally decreased to a larger extent compared to the sham. At the
site of the implant sclerosis was more prominent and in two individuals a low grade of fusion was
present. In conclusion, the results suggest that there may be an ongoing spinal fusion at the site of
the implant, but it is too early to draw conclusions three months post-surgery. Thus, further
investigations are warranted.