Ali Ghasem-Zadeh1, Andrew Burghardt2, Xiao-Fang Wang3, Sandra Iuliano3, Serena Bonaretti4, Minh Bui5, Roger Zebaze3, Ego Seeman6. 1. Department of Endocrinology and Medicine, Austin Health, University of Melbourne, Melbourne, Australia. Electronic address: alig@unimelb.edu.au. 2. Musculoskeletal Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA. 3. Department of Endocrinology and Medicine, Austin Health, University of Melbourne, Melbourne, Australia. 4. Musculoskeletal Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; Department of Radiology, Stanford University, Stanford, CA, USA. 5. Centre for Epidemiology and Biostatistics, University of Melbourne, Melbourne, Australia. 6. Department of Endocrinology and Medicine, Austin Health, University of Melbourne, Melbourne, Australia; Institute for Health and Aging, Australian Catholic University, Melbourne, Australia.
Abstract
INTRODUCTION: Individuals differ in forearm length. As microstructure differs along the radius, we hypothesized that errors may occur when sexual and racial dimorphisms are quantified at a fixed distance from the radio-carpal joint. METHODS: Microstructure was quantified ex vivo in 18 cadaveric radii using high resolution peripheral quantitative computed tomography and in vivo in 158 Asian and Caucasian women and men at a fixed region of interest (ROI), a corrected ROI positioned at 4.5-6% of forearm length and using the fixed ROI adjusted for cross sectional area (CSA), forearm length or height. Secular effects of age were assessed by comparing 38 younger and 33 older women. RESULTS: Ex vivo, similar amounts of bone mass fashioned adjacent cross sections. Larger distal cross sections had thinner porous cortices of lower matrix mineral density (MMD), a larger medullary CSA and higher trabecular density. Smaller proximal cross-sections had thicker less porous cortices of higher MMD, a small medullary canal with little trabecular bone. Taller persons had more distally positioned fixed ROIs which moved proximally when corrected. Shorter persons had more proximally positioned fixed ROIs which moved distally when corrected, so dimorphisms lessened. In the corrected ROIs, in Caucasians, women had 0.6 SD higher porosity and 0.6 SD lower trabecular density than men (p<0.01). In Asians, women had 0.25 SD higher porosity (NS) and 0.5 SD lower trabecular density than men (p<0.05). In women, Asians had 0.8 SD lower porosity and 0.3 SD higher trabecular density than Caucasians (p<0.01). In men, Asians and Caucasians had similar porosity and trabecular density. Results were similar using an adjusted fixed ROI. Adjusting for secular effects of age on forearm length resulted in the age-related increment in porosity increasing from 2.08 SD to 2.48 SD (p<0.05). CONCLUSION: Assessment of sex, race and age related differences in microstructure requires measurement of anatomically equivalent regions.
INTRODUCTION: Individuals differ in forearm length. As microstructure differs along the radius, we hypothesized that errors may occur when sexual and racial dimorphisms are quantified at a fixed distance from the radio-carpal joint. METHODS: Microstructure was quantified ex vivo in 18 cadaveric radii using high resolution peripheral quantitative computed tomography and in vivo in 158 Asian and Caucasian women and men at a fixed region of interest (ROI), a corrected ROI positioned at 4.5-6% of forearm length and using the fixed ROI adjusted for cross sectional area (CSA), forearm length or height. Secular effects of age were assessed by comparing 38 younger and 33 older women. RESULTS: Ex vivo, similar amounts of bone mass fashioned adjacent cross sections. Larger distal cross sections had thinner porous cortices of lower matrix mineral density (MMD), a larger medullary CSA and higher trabecular density. Smaller proximal cross-sections had thicker less porous cortices of higher MMD, a small medullary canal with little trabecular bone. Taller persons had more distally positioned fixed ROIs which moved proximally when corrected. Shorter persons had more proximally positioned fixed ROIs which moved distally when corrected, so dimorphisms lessened. In the corrected ROIs, in Caucasians, women had 0.6 SD higher porosity and 0.6 SD lower trabecular density than men (p<0.01). In Asians, women had 0.25 SD higher porosity (NS) and 0.5 SD lower trabecular density than men (p<0.05). In women, Asians had 0.8 SD lower porosity and 0.3 SD higher trabecular density than Caucasians (p<0.01). In men, Asians and Caucasians had similar porosity and trabecular density. Results were similar using an adjusted fixed ROI. Adjusting for secular effects of age on forearm length resulted in the age-related increment in porosity increasing from 2.08 SD to 2.48 SD (p<0.05). CONCLUSION: Assessment of sex, race and age related differences in microstructure requires measurement of anatomically equivalent regions.
Authors: D E Whittier; S K Boyd; A J Burghardt; J Paccou; A Ghasem-Zadeh; R Chapurlat; K Engelke; M L Bouxsein Journal: Osteoporos Int Date: 2020-05-26 Impact factor: 4.507
Authors: Roland Chapurlat; Minh Bui; Elisabeth Sornay-Rendu; Roger Zebaze; Pierre D Delmas; Danny Liew; Eric Lespessailles; Ego Seeman Journal: J Bone Miner Res Date: 2019-12-10 Impact factor: 6.390