Trabecular microarchitecture in established osteoporosis: relationship between vertebrae, distal radius and calcaneus by X-ray imaging texture analysis.

INTRODUCTION

Osteoporosis is an alteration of bone mass and microarchitecture leading to an increased risk of fractures. A radiograph is a 2D projection of the 3D bone network exposing a texture, that can be assessed by texture analysis. We compared the trabecular microarchitecture of the spine, radius and calcaneus in a series of osteoporotic cadavers.

MATERIALS AND

METHODS

Thirty-four cadavers (11 men, 23 women), mean age 85.2±2.1years, were radiographed from T4 to L5 to identify those with vertebral fractures (FV). Non-fractured vertebrae (NFV), radius and calcaneus were taken and analyzed by densitometry, radiography and texture analysis under run-length, skeletonization of the trabeculae, and fractal geometry.

RESULTS

Six subjects (five women, one man) were selected, mean age 82.5±5.5years. Twelve calcanei and 10 radii were taken. Two radii were excluded. The texture of NFV was significantly correlated (P<0.01) with that of the radius for horizontal run-lengths. No relationship between the texture of NFV and calcaneus was found.

DISCUSSION: In the horizontal direction (perpendicular to the stress lines), the microarchitecture of NFV and radius showed a disappearance of the transverse rods anchoring the plates. Due to its particular microarchitecture, the calcaneus is not representative of the vertebral status.

CONCLUSION

Bone densitometry provides no information about microarchitecture. Texture analysis of X-ray images of the radius would be a minimally invasive tool, providing an early detection of microarchitectural alterations.

LEVEL OF EVIDENCE: IV retrospective study.