HR-pQCT microarchitecture assessment as good as histomorphometry
MedWire News: Study findings show that non-invasive assessment of 3D microarchitecture deterioration using high-resolution peripheral quantitative tomography (HR-pQCT) is as effective as histomorphometry for detecting cortical and trabecular impairments involved in femoral neck fragility.
"HR-pQCT is used more widely to assess microarchitecture, but we are lacking comparisons between HR-pQCT and histomorphometry, which is considered the gold standard," explain Stéphanie Boutroy (University of Lyon, France) and co-authors.
For the study, the team compared the efficacy of both analytical methods for determining the distribution of cortical and trabecular bone in ultradistal femoral neck samples (approximately 3 mm thick) obtained after total hip replacement in 41 menopausal women with hip osteoarthritis or hip fracture.
Significant correlations were observed between HR-pQCT and histomorphometry for trabecular bone volume, number, thickness, separation, and cortical thickness.
Furthermore, trabecular bone pattern factor measured in 2D was significantly correlated with the structural model index (SMI) measured in 3D, and the number of nodes was significantly associated with connectivity density.
The researchers found that HRpQCT overestimated the absolute value of most parameters, with higher values most affected. In addition, agreement between the two techniques was poor for cortical porosity.
When Boutroy and team investigated differences in 3D parameters between patients with hip fracture and hip osteoarthritis, they found that those with hip fracture had 43% lower trabecular bone volume due to loss of trabeculae.
These results were also associated with a 50% loss of trabecular connectivity, mainly in the superior and inferior quadrants, characterized by a more rod-like structure as shown by the significantly higher SMI (+22%) in the hip fracture group, compared with the osteoarthritis group.
Hip fracture patients also had significantly lower cortical thickness in the posterior quadrant (-22%) than osteoarthritis patients, but cortical thickness remained highest at the inferior quadrant in both groups.
"The 3D method confirms the cortical thinning and the loss of trabecular connectivity found by histomorphometry in postmenopausal women with a femoral neck fracture when compared to women with hip osteoarthritis," conclude the authors in the journal Bone.
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By Ingrid Grasmo