Physical bone changes in carragheenin-induced arthritis evaluated by quantitative computed tomography

Area of Science:

• Veterinary Radiology
• Orthopedics
• Bone Metabolism

Background:

• Chronic arthritis significantly impacts bone structure and density.
• Non-invasive assessment of bone changes in arthritic conditions is crucial for understanding disease progression.

Purpose of the Study:

• To quantify changes in trabecular bone density (TBD), low-density bone area (LDBA), and high-density bone area (HDBA) in canine chronic arthritis using quantitative computed tomography (QCT).
• To assess the reproducibility of TBD measurements via QCT.

Main Methods:

• Induction of unilateral chronic knee arthritis in dogs using carrageenan injections over 12 weeks.
• Quantitative computed tomography (QCT) scans of distal femoral condyles in arthritic and control knees.
• Reproducibility testing of TBD measurements.
• Confirmation of QCT findings with indentation tests and histomorphometric analyses.

Main Results:

• Arthritic bone exhibited decreased TBD (P < 0.0001), increased LDBA (P < 0.0001), and decreased HDBA (P < 0.0001) compared to control bone.
• During arthritis induction, arthritic bone showed decreased TBD (P < 0.01) and HDBA (P < 0.01), with increased LDBA (P < 0.05).
• TBD measurements demonstrated high reproducibility with a coefficient of variation of 0.8%.

Conclusions:

• QCT is a reliable method for detecting significant alterations in bone density and area distribution in canine chronic arthritis.
• Chronic arthritis leads to substantial decreases in TBD and HDBA, alongside increases in LDBA, in the affected bone.
• The observed bone density changes were validated by mechanical and histological analyses.