Comparison of Buckling Ratio and Finite Element Analysis of Femoral Necks in Post-menopausal Women.
OBJECTIVE
Osteoporosis is a prevalent problem amongst the elderly. Bone mineral density (BMD) obtained from dual X-ray absorptiometry (DXA) is the gold standard in diagnosing osteopenia (-1.0 < t < -2.5) and osteoporosis (t > -2.5). However, following osteoporosis therapy, increases in BMD may be unreliable. Although hip fracture risk can be reduced with the aid of drugs, treated patients still face considerable risk as most people who sustain hip fracture do not have generalized osteoporosis. A study of the local distribution of bone mass was necessary as they contribute to the geometry and consequently the bone strength.


METHODS
By identifying the respective regions in the femoral neck, the geometric changes were localized and differed between each patient, proving that drug treatment elicits local changes in mean outer radius and mean cortical thickness. Numerical analysis also validated the above findings, where critical strain regions were predicted at similar zones and this is coherent with the fact that reduced thickness of the cortical bone has been related to increased risk of fracture initiation.


RESULTS
Hence, from individual radar plots, we can determine if the effect of drugs had outweighed the effect of aging. We can then propose a course of treatment drug better suited for the patient in the clinical scenario.


CONCLUSIONS
Clinically, little conclusion can be drawn from just the BMD in osteopenic / osteoporotic patients. This emphasizes the necessity of using geometry and structure to predict fracture risk. Focusing on a patient specific analysis at a local level will improve diagnosis of osteoporosis and ultimately fracture prediction.
Department of Biomedical Engineering, National University of Singapore, Singapore.
D
D
Anitha
Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University Health System, Seoul, Korea.
Kwang Joon
KJ
Kim
Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University Health System, Seoul, Korea.
Sung-Kil
SK
Lim
Department of Medical Biotechnology, Dongguk University, Seoul, Korea.
Taeyong
T
Lee
Bone density; Femoral neck; Finite element analysis; Postmenopause