Spine

BACKGROUND:

Great Danes (GDs) with osseous-associated cervical spondylomyelopathy (CSM) have osteoarthritis (OA) of the cervical vertebrae. OA is often associated with increases in bone mineral density (BMD) in people and dogs.

HYPOTHESIS/OBJECTIVES:

To compare the trabecular BMD of the cervical vertebrae between clinically normal (control) GDs and GDs with osseous-associated CSM by using computed tomography (CT). We hypothesized that the vertebral trabecular BMD of CSM-affected GDs would be higher than that of control GDs.

A 15 wk old male unilateral cryptorchid German shepherd dog weighing 18 kg was referred for a nonhealing cutaneous lesion dorsally at the level of the sacrum, urinary incontinence, and a deviated tail. MRI revealed spina bifida and meningomyelocele continuous with the skin surface. Surgical correction of the meningomyelocele involved closure of the open meningeal defect, transection of the abnormal spinal nerves to the skin surface, and closure of the skin defect with a good outcome. Histopathology confirmed a meningomyelocele.

OBJECTIVE:

To determine the biomechanical effect of an intervertebral spacer on construct stiffness in a PVC model and cadaveric canine cervical vertebral columns stabilized with monocortical screws/polymethylmethacrylate (PMMA).

STUDY DESIGN:

Biomechanical study.

SAMPLE POPULATION:

PVC pipe; cadaveric canine vertebral columns.

METHODS:

Presence of residual material following mini-hemilaminectomy in dogs (n = 9) with spontaneous thoracolumbar intervertebral disc extrusion was prospectively investigated. Volume of extruded disc material within the vertebral canal and the proportion of residual material were determined using pre- and post-operative magnetic resonance imaging. The degree of spinal cord compression, proportion of extradural material considered hemorrhage, and invasion of the articular facets were also determined. Residual material was identified in 44% of the mini-hemilaminectomies.