J Bone Metab.  2014 Nov;21(4):243-247. 10.11005/jbm.2014.21.4.243.

Assessing Bone Quality in Terms of Bone Mineral Density, Buckling Ratio and Critical Fracture Load

• Anitha D
• Lee T

• KMID: 2170051
• DOI: http://doi.org/10.11005/jbm.2014.21.4.243

Abstract

BACKGROUND
Bone mineral density (BMD) is used as a sole parameter in the diagnosis of osteoporosis. Due to the ease of acquirement of BMD, clinical diagnosis still involves its usage although the limitations of BMD are quite well-established. Therefore, this preliminary study hoped to reduce the errors introduced by BMD alone by incorporating geometric and structural predictors simultaneously to observe if strength was implicitly dependent on the geometry and BMD. Hence, we illustrated the triadic relationship between BMD, buckling ratio (BR) and critical fracture load (Fcr).
METHODS
The geometric predictor was the BR as it involves both the changes in the periosteum and the cortical thickness. Also, structural changes were monitored by finite element (FE) analysis-predicted Fcr. These BR and Fcr measurements were plotted with their respective femoral neck BMD values in elderly female patients (n=6) in a 3-year follow-up study, treated with ibandronate.
RESULTS
In all the three-dimensional plots (baseline, mid and final year), high Fcr values were found at regions containing high BMD and low BR values. Quantitatively, this was also proven where an averaged highest Fcr across the three years had a relatively higher BMD (46%) and lower BR (19%) than that of the averaged lowest Fcr. The dependence of FE predicted strength on both the geometry and bone density was illustrated.
CONCLUSIONS
We conclude that use of triadic relationships for the evaluation of osteoporosis and hip fractures with the combination of strength, radiology-derived BR and bone density will lay the foundation for more accurate predictions in the future.

Keyword

Bone density; Femur neck; Finite element analysis; Osteoporotic fractures

MeSH Terms

Aged
Bone Density*
Diagnosis
Female
Femur Neck
Finite Element Analysis
Follow-Up Studies
Hip Fractures
Hope
Humans
Osteoporosis
Osteoporotic Fractures
Periosteum

Figure

• 

  Fig. 1 Obtainment of outer radius and cortical thickness from profile rays drawn on narrowest neck slice. After extraction of femoral neck region, profile rays were drawn at 30° intervals, measured from the centroid of the femoral neck slice. A sample profile ray at 0° is shown where respective regions of cortical bone, trabecular bone and soft tissues are identified.

• 

  Fig. 2 Yearly three-dimensional surface plots of bone mineral density (BMD), buckling ratio and fracture load (Fcr). High Fcr values were found at regions containing high BMD and low BR values.

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