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Comparison of the new QUS parameters from the novel QUS machine (LD-100) to DXA and formal QUS parameters
Abstracts / Bone 44 (2009) S68–S98
considerably muted. Muscle and balance function can be improved with very minimal exposure to high intensity WBV. Findings have important clinical implications for groups at high risk of hip fracture who are unable or unwilling to adopt traditional therapeutic options. (1) Weeks BK and Beck BR: The BPAQ: a bone-specific physical activity assessment instrument. Osteoporosis International, 19(11): 1567–1577, 2008. doi:10.1016/j.bone.2009.01.154
239 Comparison of the new QUS parameters from the novel QUS machine (LD-100) to DXA and formal QUS parameters P. Bejrachandraa, K. Yohb, P. Yuktanandanac, I. Manod, K. Horiid, T. Tsujimotoe, T. Otanif a Radiological Technology, Chulalongkorn University, Bangkok, Thailand b Orthopedic Surgery, Hyogo College of Medicine, Sasayama, Japan c Orthopedic Surgery, Chulalongkorn University, Bangkok, Thailand d OYO Electric Co.,Ltd., Kyoto, Japan e Horiba Ltd., Tokyo, Japan f Engineering, Doshisha University, Kyotanabe, Japan As we know, the difference in weight bearing on each bone affects the difference in bone density and bone composition of cortical bone and cancellous bone. Those two forms of bone grade into one another without a sharp boundary, even if they are much different in mass and metabolic turnover rate. Concerning Biot's theory, the novel QUS machine (LD-100) was established, providing 5 parameters with the new concept in detection of each bone status. After the confidential in in vitro experiment, LD-100 was developed for clinical practice to this study. One hundred and nine Japanese patients (62 female and 47 male) aged 49 +/− 17 years were assessed at left forearm with LD-100 (QUS), at lumbar spine and at left forearm with Lunar (DXA), and at left calcaneous with Achilles+ (QUS). We found that the Pearson's correlation of BMD or bone mineral density (DXA at spine) to BUA or broadband ultrasound attenuation and BV/TV or cancellous bone volume fraction (LD-100) were moderate (0.48 and 0.46 respectively), while to BMD (DXA at forearm) and BUA (Achilles+) were also moderate (0.47 and 0.45 respectively). The most attractive for all crossover comparisons was the good correlation of the same site by different technologies as at the left forearm by LD-100 (BUA) and DXA (BMD) was 0.69 and the same technology on the different site as LD-100 (BUA) at the forearm and Achilles+ (BUA) at calcaneous was 0.64. Also the radius thickness (Rd.Th) parameter showed increasing correspondence with the patients' age increasing. Conclusion: Lunar, LD-100, and Achilles+ can interpret the overall bone density, moreover, LD-100 can interpret more bone status as BV/TV, Rd.Th, Ct.Th, and Cn.El. Those information are significant not only for diagnostic of osteoporosis but also for future advance research in drug formation and its effective dose studying. doi:10.1016/j.bone.2009.01.155
240 Age-related differences in thoracic and lumbar vertebral bone density and strength assessed using QCT-based finite element analysis B.A. Christiansena, D. Kopperdahlb, M.J. Valentinea, B.J. Robertsa, T.M. Keavenyb,d, D.P. Kielc, M.L. Bouxseina a Orthopedic Biomechanics Laboratory, Beth Israel Deaconess Medical Center, Boston, MA, USA
S71
b
O.N. Diagnostics, Berkeley, CA, USA Institute for Aging Research, Hebrew Senior Life, Boston, MA, USA d Department of Mechanical Engineering, University of California – Berkeley, Berkeley, CA, USA c
Conventional assessment of vertebral fracture risk has relied on areal bone mineral density of the lumbar vertebrae (L1–L4), even though vertebral fractures often occur in the thoracic region. Thus, we sought to investigate whether age-related declines in vertebral strength are similar in lumbar and thoracic vertebrae, and whether lumbar vertebral strength can be used to accurately predict thoracic vertebral strength. To do this, we used QCT-voxel based finite element analyses (FEA) (Keaveny et al., JBMR 2007) to assess vertebral strength in lumbar (L3) and thoracic (T10) vertebrae of 21 young (36 to 40 yrs) and 25 old (71 to 78 yrs) women from the Framingham Heart Study Offspring and Third Generation Multidetector CT Study. Mean compressive strengths of L3 and T10 vertebrae were both lower in old subjects than young subjects (4666 ± 1274 vs. 10030 ± 1654 N for L3; 4249 ± 1360 vs. 7627 ± 1702 N for T10), and were associated with decreases in trabecular compressive strength of L3 and T10 of 65% and 54%, respectively (Table 1). Table 1 QCT- and FEA-derived vertebral properties Average % difference Young vs. old
Compressive strength Trabecular comp. strength Cortical comp. strength Bending stiffness Axial stiffness Integral BMD Trabecular BMD Cortical BMD
L3
T10
53.5⁎a 65.2⁎a 36.9⁎ 38.3⁎ 46.4⁎ 39.5⁎ 44.2⁎ 29.4⁎
44.3⁎ 54.0⁎ 31.0⁎ 25.7⁎⁎ 37.6⁎ 34.1⁎ 38.4⁎ 25.6⁎
Young vs. old: ⁎p < 0.0001. ⁎⁎p < 0.005. a Age by vertebral level interaction: p < 0.01.
Interestingly, differences between old and young subjects were larger for L3 than T10 for all parameters measured, and the interaction between age and vertebral level was statistically significant for compressive strength and trabecular compressive strength (p < 0.01). The correlation between compressive strengths of L3 and T10 was moderately strong (r2 = 0.54 for both old and young women). Taken together, these data demonstrate a heterogeneity in vertebral strength across levels and over adulthood, due mostly to changes in the trabecular compartment. Accounting for this heterogeneity between vertebral levels may provide new insight into vertebral fracture etiology. doi:10.1016/j.bone.2009.01.156
241 Blunted skeletal response to PTH retreatment in mice following an interruption in dosing M.J. Devlin, D.A. Panus, M.L. Bouxsein Orthopedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA Aim: Teriparatide (hPTH (1–34)) is approved for the treatment of osteoporosis, but duration of therapy is limited to 2 years. Thus little is known about the skeletal response to interruptions in PTH treatment followed by retreatment. Methods: We compared the skeletal response to PTH in retreated vs. treatment-naïve male C57Bl/6J mice. The retreatment group (RETREAT, N = 4) received hPTH injections (40 μg/kg/day, sc, 5×/
considerably muted. Muscle and balance function can be improved with very minimal exposure to high intensity WBV. Findings have important clinical implications for groups at high risk of hip fracture who are unable or unwilling to adopt traditional therapeutic options. (1) Weeks BK and Beck BR: The BPAQ: a bone-specific physical activity assessment instrument. Osteoporosis International, 19(11): 1567–1577, 2008. doi:10.1016/j.bone.2009.01.154
239 Comparison of the new QUS parameters from the novel QUS machine (LD-100) to DXA and formal QUS parameters P. Bejrachandraa, K. Yohb, P. Yuktanandanac, I. Manod, K. Horiid, T. Tsujimotoe, T. Otanif a Radiological Technology, Chulalongkorn University, Bangkok, Thailand b Orthopedic Surgery, Hyogo College of Medicine, Sasayama, Japan c Orthopedic Surgery, Chulalongkorn University, Bangkok, Thailand d OYO Electric Co.,Ltd., Kyoto, Japan e Horiba Ltd., Tokyo, Japan f Engineering, Doshisha University, Kyotanabe, Japan As we know, the difference in weight bearing on each bone affects the difference in bone density and bone composition of cortical bone and cancellous bone. Those two forms of bone grade into one another without a sharp boundary, even if they are much different in mass and metabolic turnover rate. Concerning Biot's theory, the novel QUS machine (LD-100) was established, providing 5 parameters with the new concept in detection of each bone status. After the confidential in in vitro experiment, LD-100 was developed for clinical practice to this study. One hundred and nine Japanese patients (62 female and 47 male) aged 49 +/− 17 years were assessed at left forearm with LD-100 (QUS), at lumbar spine and at left forearm with Lunar (DXA), and at left calcaneous with Achilles+ (QUS). We found that the Pearson's correlation of BMD or bone mineral density (DXA at spine) to BUA or broadband ultrasound attenuation and BV/TV or cancellous bone volume fraction (LD-100) were moderate (0.48 and 0.46 respectively), while to BMD (DXA at forearm) and BUA (Achilles+) were also moderate (0.47 and 0.45 respectively). The most attractive for all crossover comparisons was the good correlation of the same site by different technologies as at the left forearm by LD-100 (BUA) and DXA (BMD) was 0.69 and the same technology on the different site as LD-100 (BUA) at the forearm and Achilles+ (BUA) at calcaneous was 0.64. Also the radius thickness (Rd.Th) parameter showed increasing correspondence with the patients' age increasing. Conclusion: Lunar, LD-100, and Achilles+ can interpret the overall bone density, moreover, LD-100 can interpret more bone status as BV/TV, Rd.Th, Ct.Th, and Cn.El. Those information are significant not only for diagnostic of osteoporosis but also for future advance research in drug formation and its effective dose studying. doi:10.1016/j.bone.2009.01.155
240 Age-related differences in thoracic and lumbar vertebral bone density and strength assessed using QCT-based finite element analysis B.A. Christiansena, D. Kopperdahlb, M.J. Valentinea, B.J. Robertsa, T.M. Keavenyb,d, D.P. Kielc, M.L. Bouxseina a Orthopedic Biomechanics Laboratory, Beth Israel Deaconess Medical Center, Boston, MA, USA
S71
b
O.N. Diagnostics, Berkeley, CA, USA Institute for Aging Research, Hebrew Senior Life, Boston, MA, USA d Department of Mechanical Engineering, University of California – Berkeley, Berkeley, CA, USA c
Conventional assessment of vertebral fracture risk has relied on areal bone mineral density of the lumbar vertebrae (L1–L4), even though vertebral fractures often occur in the thoracic region. Thus, we sought to investigate whether age-related declines in vertebral strength are similar in lumbar and thoracic vertebrae, and whether lumbar vertebral strength can be used to accurately predict thoracic vertebral strength. To do this, we used QCT-voxel based finite element analyses (FEA) (Keaveny et al., JBMR 2007) to assess vertebral strength in lumbar (L3) and thoracic (T10) vertebrae of 21 young (36 to 40 yrs) and 25 old (71 to 78 yrs) women from the Framingham Heart Study Offspring and Third Generation Multidetector CT Study. Mean compressive strengths of L3 and T10 vertebrae were both lower in old subjects than young subjects (4666 ± 1274 vs. 10030 ± 1654 N for L3; 4249 ± 1360 vs. 7627 ± 1702 N for T10), and were associated with decreases in trabecular compressive strength of L3 and T10 of 65% and 54%, respectively (Table 1). Table 1 QCT- and FEA-derived vertebral properties Average % difference Young vs. old
Compressive strength Trabecular comp. strength Cortical comp. strength Bending stiffness Axial stiffness Integral BMD Trabecular BMD Cortical BMD
L3
T10
53.5⁎a 65.2⁎a 36.9⁎ 38.3⁎ 46.4⁎ 39.5⁎ 44.2⁎ 29.4⁎
44.3⁎ 54.0⁎ 31.0⁎ 25.7⁎⁎ 37.6⁎ 34.1⁎ 38.4⁎ 25.6⁎
Young vs. old: ⁎p < 0.0001. ⁎⁎p < 0.005. a Age by vertebral level interaction: p < 0.01.
Interestingly, differences between old and young subjects were larger for L3 than T10 for all parameters measured, and the interaction between age and vertebral level was statistically significant for compressive strength and trabecular compressive strength (p < 0.01). The correlation between compressive strengths of L3 and T10 was moderately strong (r2 = 0.54 for both old and young women). Taken together, these data demonstrate a heterogeneity in vertebral strength across levels and over adulthood, due mostly to changes in the trabecular compartment. Accounting for this heterogeneity between vertebral levels may provide new insight into vertebral fracture etiology. doi:10.1016/j.bone.2009.01.156
241 Blunted skeletal response to PTH retreatment in mice following an interruption in dosing M.J. Devlin, D.A. Panus, M.L. Bouxsein Orthopedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA Aim: Teriparatide (hPTH (1–34)) is approved for the treatment of osteoporosis, but duration of therapy is limited to 2 years. Thus little is known about the skeletal response to interruptions in PTH treatment followed by retreatment. Methods: We compared the skeletal response to PTH in retreated vs. treatment-naïve male C57Bl/6J mice. The retreatment group (RETREAT, N = 4) received hPTH injections (40 μg/kg/day, sc, 5×/