Subchondral bone microarchitecture analysis in the proximal tibia at 7-T MRI

Area of Science:

• Orthopedics
• Radiology
• Biomedical Engineering

Background:

• Bone remodeling is crucial for skeletal health, and osteoporosis signifies impaired bone remodeling.
• Bone microarchitecture analysis offers insights into bone quality beyond traditional bone mineral density (BMD) measurements.

Purpose of the Study:

• To compare subchondral bone microarchitecture parameters in the medial and lateral tibia plateau between individuals with and without fragility fractures.
• To investigate if advanced imaging techniques can detect bone quality differences not apparent with standard BMD assessments.

Main Methods:

• Twelve female patients (mean age 58 years), six with and six without fragility fractures, underwent dual-energy X-ray absorptiometry (DXA) and 7-Tesla (7-T) magnetic resonance imaging (MRI) of the proximal tibia.
• High-resolution 3D MRI data were analyzed using Digital Topological Analysis (DTA) to assess parameters like apparent bone volume, trabecular thickness, and erosion indices.
• Comparisons were made between groups for femoral neck T-scores and various DTA-derived bone microarchitecture parameters.

Main Results:

• No significant difference in femoral neck T-scores (a measure of BMD) was observed between patients with and without fragility fractures.
• Apparent bone volume was significantly lower in the medial tibial compartment of patients with prior fragility fractures (P=0.016).
• Profile-edge-density, indicating trabecular bone erosion, was significantly higher in both medial and lateral tibial compartments of patients with fragility fractures (P=0.025 for both).

Conclusions:

• 7-Tesla MRI combined with Digital Topological Analysis can detect subtle alterations in subchondral bone quality associated with fragility fractures.
• These microarchitectural changes are identifiable even when bone mineral density (BMD) measurements do not show significant differences.
• Advanced imaging analysis of subchondral bone may provide valuable information for assessing fracture risk.