Cortical Bone Thickness and Bone Mineral Density
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Letter to the Editor Cortical Bone Thickness and Bone Mineral Density The main purpose of this study is to see if there is any relationship between the T-scores of hip cortical thick- ness and the bone mineral density measured by using dual-energy X-ray absorptiometry (DXA). We looked at 72 consecutive bone densities done on 72 women aged older than 50 years. All the scans were done in our osteoporosis center using the same machine and the same technician. We measured the cortical bone thickness and the ratio of the cortical bone to the diameter of the hip and com- pared it with the T-score of the left hip, right hip, and L1eL4 spine. Weak correlation was found between the ratio for the right and left hip and the T-score of the hip and even weaker relationship to the T-score of the spine. More data are needed to evaluate this further. The study was designed to measure several items. We measured the T-score for the left and the right hip and for the lumbar spine. To assess the size of the cortical bone, we used the image from the DXA scan and measured the width in millimeters adding the sides (a þ b). For measur- ing the ratio, we divided a þ b by the diameter of the hip at the same location (Fig. 1). One person did the measure- ments. For the design, we used clinical correlation. Weak correlation was found between the ratio for the right and left hip and the T-score of the hip and even weaker relationship to the T-score of the spine. There was no significant difference between the right and left hip ratios. We did a Google research of our topic ‘‘Cortical Bone Thickness and Bone Mineral Density’’ and we were able to limit the search to 27,900 results. By avoiding certain words, such as dental, we were able to find 9 articles that were relevant to our topic. We did review some key articles that correlate between cortical thickness and bone density, and we found that these topics have been addressed but we did not see any definite measurement used to assess that. Some of the ar- ticles we have seen address the pathogenesis of bone fragility in women and men, such as fewer or thinner tra- beculae, and thin cortices, all of which result in low peak bone density (1). Structural properties, such as the diam- eter and thickness of the cortices, the porosity of the cor- tical shell, the connectivity and anisotropy of the trabecular network, the thickness of trabeculae, and the presence of trabecular stress risers and microcracks im- pact bone strength in diverse manners (2). Measurement of the cortical thickness of long bones is the best method of quantitatively diagnosing osteoporosis (3). Fig. 1. To assess the size of the cortical bone using the DXA scan, measure the width in millimeters and add the sides (a þ b). To measure the ratio, divide a þ b by the diameter of the hip at the same location. 127 Journal of Clinical Densitometry: Assessment of Skeletal Health, vol. 16, no. 1, 127e128, 2013 Ó Copyright 2013 by The International Society for Clinical Densitometry 1094-6950/16:127e128/$36.00 http://dx.doi.org/10.1016/j.jocd.2012.07.007
Transcript of Cortical Bone Thickness and Bone Mineral Density
Journal of Clinical Densitometry: Assessment of Skeletal Health, vol. 16, no. 1, 127e128, 2013� Copyright 2013 by The International Society for Clinical Densitometry1094-6950/16:127e128/$36.00
http://dx.doi.org/10.1016/j.jocd.2012.07.007Letter to the Editor
Cortical Bone Thickness and Bone Mineral Density
Fig. 1. To assess the size of the cortical bone using theDXA scan, measure the width in millimeters and add the sides(a þ b). To measure the ratio, divide a þ b by the diameter ofthe hip at the same location.
The main purpose of this study is to see if there is anyrelationship between the T-scores of hip cortical thick-ness and the bone mineral density measured by usingdual-energy X-ray absorptiometry (DXA).
We looked at 72 consecutive bone densities done on72 women aged older than 50 years. All the scanswere done in our osteoporosis center using the samemachine and the same technician.
We measured the cortical bone thickness and the ratioof the cortical bone to the diameter of the hip and com-pared it with the T-score of the left hip, right hip, andL1eL4 spine.
Weak correlation was found between the ratio for theright and left hip and the T-score of the hip and evenweaker relationship to the T-score of the spine. Moredata are needed to evaluate this further.
The study was designed to measure several items. Wemeasured the T-score for the left and the right hip and forthe lumbar spine. To assess the size of the cortical bone,we used the image from the DXA scan and measured thewidth in millimeters adding the sides (aþ b). For measur-ing the ratio, we divided aþ b by the diameter of the hip atthe same location (Fig. 1). One person did the measure-ments. For the design, we used clinical correlation.
Weak correlation was found between the ratio for theright and left hip and the T-score of the hip and evenweaker relationship to the T-score of the spine. Therewas no significant difference between the right andleft hip ratios.
We did a Google research of our topic ‘‘Cortical BoneThickness and Bone Mineral Density’’ and we were ableto limit the search to 27,900 results. By avoiding certainwords, such as dental, we were able to find 9 articles thatwere relevant to our topic.
We did review some key articles that correlate betweencortical thickness and bone density, and we found thatthese topics have been addressed but we did not see anydefinite measurement used to assess that. Some of the ar-ticles we have seen address the pathogenesis of bone
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fragility in women and men, such as fewer or thinner tra-beculae, and thin cortices, all of which result in low peakbone density (1). Structural properties, such as the diam-eter and thickness of the cortices, the porosity of the cor-tical shell, the connectivity and anisotropy of thetrabecular network, the thickness of trabeculae, and thepresence of trabecular stress risers and microcracks im-pact bone strength in diverse manners (2). Measurementof the cortical thickness of long bones is the best methodof quantitatively diagnosing osteoporosis (3).
128 Letter to the Editor
We do recommend addressing this important subjectin a more detailed manner in the future.
Souhail G. ShamiyehElias G. ShamiyehVaishali Chhaya
Internal Medicine Associates of NortonNorton, VA, USA
Journal of Clinical Densitometry: Assessment of Skeletal Health
References
1. Seeman E. 2002 Pathogenesis of bone fragility in women andmen. Lancet 359(9320):1841e1850.
2. Davison KS, Siminoski K, Adachi JD, et al. 2006 Bone strength:the whole is greater than the sum of its parts. Semin ArthritisRheum 36(1):22e31.
3. BloomRA. 1980.Acomparative estimation of thecombinedcorticalthickness of various bone sites. Skeletal Radiol 5(3):167e170.
Volume 16, 2013
