Subchondral Bone Density Distribution in Canine C6-C7 Vertebral Endplates Affected by DA-CSM: A CT-OAM Study

Area of Science:

• Veterinary Orthopedics
• Canine Spinal Surgery
• Biomechanical Analysis

Background:

• Disc-associated cervical spondylomyelopathy (DA-CSM) is a common canine spinal disorder.
• Implant subsidence is a frequent complication following surgical stabilization for DA-CSM.
• Understanding subchondral bone density is crucial for surgical outcomes.

Purpose of the Study:

• To evaluate subchondral bone mineral density (sBMD) in the C6-C7 motion unit of DA-CSM-affected dogs.
• To compare sBMD distribution in affected dogs with clinically unaffected controls.
• To investigate the relationship between sBMD patterns and implant subsidence risk.

Main Methods:

• Computed tomography osteoabsorptiometry (CT-OAM) was used to analyze sBMD.
• sBMD was measured in annulus fibrosus (AF) and nucleus pulposus (NP) regions.
• Statistical analysis included t-tests and Chi-squared tests for comparisons.

Main Results:

• DA-CSM affected vertebrae showed significantly reduced overall sBMD compared to controls (p < 0.0001).
• This reduction affected all regions (AF, NP) and topographic subdivisions.
• The spatial distribution pattern of sBMD (high in peripheral AF, low in central NP) was similar between affected and unaffected dogs.

Conclusions:

• DA-CSM is associated with generalized subchondral bone density reduction.
• The intrinsic load-adapted sBMD distribution pattern is preserved.
• Reduced bone quality and persistent weak central regions may increase implant subsidence risk, informing surgical strategies.