TITLE:
Probability of Osteoporotic Vertebral Fractures Assessment Based on DXA Measurements and Finite Element Simulation
AUTHORS:
Enrique López, Elena Ibarz, Antonio Herrera, Jesús Mateo, Antonio Lobo-Escolar, Sergio Puértolas, Luis Gracia
KEYWORDS:
Osteoporosis, Osteoporotic Vertebral Fracture, Predictive Model, Finite Elements, Fracture Risk, Fracture Probability
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.5 No.6,
May
16,
2014
ABSTRACT:
Osteoporotic
vertebral fractures represent major cause of disability, loss of quality of
life and even mortality among the elderly population. Decisions on drug therapy
are based on the assessment of risk factors for fracture, from bone mineral
density measurements. The combination of biomechanical models with clinical
studies could better estimate bone strength and support the specialists in their decision. A model to assess
the probability of fracture, based on the Damage and Fracture Mechanics has
been developed, evaluating the mechanical magnitudes involved in the fracture
process from clinical bone mineral density measurements. The model is intended for simulating the degenerative process in the
skeleton, with the consequent lost of bone mass and hence the decrease of its
mechanical resistance which enables the fracture due to different traumatisms. Clinical studies
were chosen, both in non-treatment conditions and receiving drug therapy, and
fitted to specific patients according their actual bone mineral density
measures. The predictive model is applied in a finite element simulation of the
lumbar spine. The fracture zone
would be determined according loading scenario (fall, impact, accidental loads,
etc.), using the mechanical properties of bone obtained from the evolutionary
model corresponding to the considered time. Bone mineral
density evolution in untreated patients and in those under different treatments
was analyzed. Evolutionary curves of fracture probability were obtained from
the evolution of mechanical damage. The evolutionary curve of the untreated
group of patients presented a marked increase of the fracture probability,
while the curves of patients under drug treatment showed variable decreased
risks, depending on the therapy type. The finite element model allowed
obtaining detailed maps of damage and fracture
probability, identifying high-risk local zones at vertebral body, which are the
usual localization of osteoporotic vertebral fractures. The developed
model is suitable for being used in individualized cases. The model might
better identify at-risk individuals in early stages of osteoporosis and might
be helpful for treatment decisions.