Biomechanical evaluation of two methods of surgical stabilization of the atlantoaxial joint

Several methods of surgical stabilization of the atlantoaxial joint are described in the veterinary literature. Threaded acrylic pins placed ventrally together with polymethylmethacrylate (PMMA) is a well-established technique that has been widely used in clinical cases. However, Kishigami tension bands are a less technically demanding procedure with potentially fewer complications. The purpose of this study was to biomechanically compare these two techniques in ventral-to-dorsal bending in both mature and immature dogs. Seventeen normal canine cadavers <15kg were collected and radiographed to determine skeletal maturity. The cervical spines were dissected leaving bony and ligamentous structures intact. Eight mature spines and 9 immature spines were randomly divided into two groups. In one group a Kishigami tension band was applied over the dorsal arch of the atlas and attached to the spinous process of the axis using orthopedic wire. In the second group, six acrylic pins were placed ventrally in the atlas, axis, and transarticularly. The pins were then cut and covered with PMMA. The specimens were potted in custom steel pots and biomechanically analyzed in ventral-to-dorsal four-point bending. Load-displacement curves representing the degree of stiffness were compared between the groups. Stabilization using ventral pins and PMMA had a significantly greater stiffness than a Kishigami tension band when bending in ventral to dorsal bending. Within the stabilized vertebral segment, there was no significant difference between the stiffness of immature vs. mature bone. Further analysis in torsion and analysis in abnormal dogs will be helpful in establishing the clinical significance of these findings.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biomedical and Veterinary Sciences

Department dc:contributor.department

Veterinary Medicine

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2013

Author dc:creator

• Kopf, Kelli Michaela

Chair dc:contributor.committeechair

• Inzana, Karen D.

Committee members dc:contributor.committeemember

• Rossmeisl, John H. Jr.
• Lanz, Otto I.

• Atlantoaxial
• Kishigami tension band
• Pins and polymethylmethacrylate
• canine
• subluxation

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:1458

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/23720