Effect of finite element model loading condition on fracture risk assessment in men and women: The AGES-Reykjavik study

• Published in: Bone (New York, N.Y.) Vol. 57; no. 1; pp. 18 - 29
• Main Authors: Keyak, J.H., Sigurdsson, S., Karlsdottir, G.S., Oskarsdottir, D., Sigmarsdottir, A., Kornak, J., Harris, T.B., Sigurdsson, G., Jonsson, B.Y., Siggeirsdottir, K., Eiriksdottir, G., Gudnason, V., Lang, T.F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.11.2013; Elsevier
• Subjects: Aged; Aged, 80 and over; Biological and medical sciences; Bone strength; Clinical Medicine; Diseases of the osteoarticular system; Female; Femur; Finite Element Analysis; Fractures, Bone - diagnostic imaging; Fundamental and applied biological sciences. Psychology; Hip fracture; Hip Fractures - diagnostic imaging; Humans; Injuries of the limb. Injuries of the spine; Klinisk medicin; Male; Medical and Health Sciences; Medical sciences; Medicin och hälsovetenskap; Orthopaedics; Orthopedics; Ortopedi; Osteoporosis; Osteoporosis - diagnostic imaging; Osteoporosis. Osteomalacia. Paget disease; Prospective Studies; Quantitative computed tomography; Radiography; Traumas. Diseases due to physical agents; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Femur; FPL; FL; FP; L; FStance; P; Osteoporosis; Hip fracture; Quantitative computed tomography; Finite element analysis; PL; Bone strength; FE; finite element analysis-computed proximal femoral strength for loading representing a fall onto the posterolateral aspect of the greater trochanter; posterolateral; finite element; F Stance; posterior; lateral; finite element analysis-computed proximal femoral strength for loading similar to that during single-limb stance; F L; F PL; F P; finite element analysis-computed proximal femoral strength for loading representing a fall onto the lateral aspect of the greater trochanter; finite element analysis-computed proximal femoral strength for loading representing a fall onto the posterior aspect of the greater trochanter; Human; Radiodiagnosis; Diseases of the osteoarticular system; Fracture; Trauma; Hip; Morphology; Risk factor; Medical imagery; Models; Computerized axial tomography; Bone; Woman; Age; Strength; Quantitative analysis; Finite element; F(PL); F(Stance); F(P); F(L)
• ISSN: 8756-3282; 1873-2763; 1873-2763
• DOI: 10.1016/j.bone.2013.07.028

Proximal femoral (hip) strength computed by subject-specific CT scan-based finite element (FE) models has been explored as an improved measure for identifying subjects at risk of hip fracture. However, to our knowledge, no published study has reported the effect of loading condition on the association between incident hip fracture and hip strength. In the present study, we performed a nested age- and sex-matched case–control study in the Age Gene/Environment Susceptibility (AGES) Reykjavik cohort. Baseline (pre-fracture) quantitative CT (QCT) scans of 5500 older male and female subjects were obtained. During 4–7years follow-up, 51 men and 77 women sustained hip fractures. Ninety-seven men and 152 women were randomly selected as controls from a pool of age- and sex-matched subjects. From the QCT data, FE models employing nonlinear material properties computed FE-strength of the left hip of each subject in loading from a fall onto the posterolateral (FPL), posterior (FP) and lateral (FL) aspects of the greater trochanter (patent pending). For comparison, FE strength in stance loading (FStance) and total femur areal bone mineral density (aBMD) were also computed. For all loading conditions, the reductions in strength associated with fracture in men were more than twice those in women (p≤0.01). For fall loading specifically, posterolateral loading in men and posterior loading in women were most strongly associated with incident hip fracture. After adjusting for aBMD, the association between FP and fracture in women fell short of statistical significance (p=0.08), indicating that FE strength provides little advantage over aBMD for identifying female hip fracture subjects. However, in men, after controlling for aBMD, FPL was 424N (11%) less in subjects with fractures than in controls (p=0.003). Thus, in men, FE models of posterolateral loading include information about incident hip fracture beyond that in aBMD. •We performed a prospective study of hip fracture in a group of older men and women.•Finite element-computed hip strength in fracture and control subjects was obtained.•Stance and posterolateral, posterior and lateral fall loading were analyzed.•Posterolateral and posterior loading in men and women, respectively, were most strongly associated with hip fracture.