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Quantitative bone analysis in children: Current methods and recommendations
LETTERS
Quantitative bone analysis in children: Current methods and recommendations To the Editor: Recently, Specker and Schoenau discussed on the current methods to estimate bone mineral density (BMD) in children, but poor information on quantitative ultrasound (QUS) methods was given, and the discussion focused exclusively on calcaneal QUS.1 In children, many studies have been recently published on QUS measurement at other skeletal sites, such as proximal phalanges of the hand and tibia, that, in my opinion, cannot be neglected in a review article. It should be considered that QUS methods differ in the site of skeletal measurement and then in its structure, and in the examined QUS parameters, some of which are more appropriate for estimating bone mineral status (eg, phalangeal bone transmission time that excludes the influence of soft tissues).2 Moreover, large reference databases are available for phalangeal QUS according to the main auxologic features.2,3 Furthermore, phalangeal QUS is poorly influenced by bone size 3 compared with calcaneal QUS and DXA, and it is able to assess fracture risk in children with bone and mineral disorders.4 I agree with the authors that peripheral quantitative computed tomography is the more accurate method to assess BMD, but it is not applicable in infants and in very small children; it exposes the child to x-ray even if the radiation is low, and it is not diffused. On the contrary, phalangeal QUS may be used in newborns (also in preterm infants); the method is radiation-free, and it is more diffused. Moreover, there are valuable and growing clinical experiences. In conclusion, phalangeal QUS should be considered a valid method to estimate bone mineral status in infants, children, and adolescents. Giampiero I. Baroncelli, MD Department of Reproductive Medicine and Pediatrics Division of Pediatrics University of Pisa Pisa, Italy 10.1016/j.jpeds.2006.01.012
REFERENCES 1. Specker BL, Schoenau E. Quantitative bone analysis in children: current methods and recommendations. J Pediatr 2005;146:726-31. 2. Barkmann R, Rohrschneider W, Vierling M, Troger J, de TF, Cadossi R, et al. German pediatric reference data for quantitative transverse transmission ultrasound of finger phalanges. Osteoporos Int 2002;13:55-61. 3. Baroncelli GI, Federico G, Bertelloni S, de Terlizzi F, Cadossi R, Saggese G. Bone quality assessment by quantitative ultrasound of proximal phalanxes of the hand in healthy subjects aged 3 to 21 years. Pediatr Res 2001;49:713-8. 4. Baroncelli GI, Federico G, Bertelloni S, Sodini F, De Terlizzi F, Cadossi R, et al. Assessment of bone quality by quantitative ultrasound of
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proximal phalanges of the hand and fracture rate in children and adolescents with bone and mineral disorders. Pediatr Res 2003;54:125-36.
Reply To the Editor: We are grateful for Dr Baroncelli’s comments on the utility of quantitative ultrasound (QUS) for examining skeletal development in children and adolescents. We agree that a significant amount of publications have presented QUS data, both in healthy children and in various pediatric bone disorders. However, the main purpose of our review was to point out strengths and weaknesses of the various methods to examine skeletal development and to highlight the necessity for further improvements. QUS has major limitations in that this technique does not allow distinguishing between bone mass, density, and geometry. Skeletal development is characterized by concomitant changes in these parameters. If we aim at a deeper understanding of the physiology and pathophysiology of bone development, we need methods that analyze bone mass, density, and geometry separately. There is no doubt that the lack of radiation exposure makes ultrasound methods attractive at first glance. Unfortunately, this advantage comes at the price of ill-defined analytical results. It is also important to re-emphasize that the results of many QUS methods depend on bone size (and thus body height). In contrast to Dr Baroncelli’s statement on this matter, some authors have found that this is also true for phalangeal QUS.1,2 We also believe that Dr Baroncelli’s conclusion is overly optimistic. Eckhard Schönau Children’s Hospital, University of Cologne D-50924 Köln, Germany Bonny Specker, PhD E. A. Martin Program in Human Nutrition, South Dakota State University, Brookings, SD 57007 10.1016/j.jpeds.2006.02.008
REFERENCES 1. Schönau E. Problems of bone analysis in childhood and adolescence. Pediatr Nephrol 1998;12:420-9. 2. Fricke O, Tutlewski B, Schoenau E. Speed of sound: relationship to geometrical characteristics of bone in children adolescents and adults. J Pediatr 2005;146:764-8.
Evidence-based protocols for oral NSAID challenges To the Editor: Debley et al interpret their data as indicating that ⬎100,000 asthmatic children are at risk for bronchospasm from ibuprofen.1 We disagree and believe their study did not The Journal of Pediatrics • May 2006
Quantitative bone analysis in children: Current methods and recommendations To the Editor: Recently, Specker and Schoenau discussed on the current methods to estimate bone mineral density (BMD) in children, but poor information on quantitative ultrasound (QUS) methods was given, and the discussion focused exclusively on calcaneal QUS.1 In children, many studies have been recently published on QUS measurement at other skeletal sites, such as proximal phalanges of the hand and tibia, that, in my opinion, cannot be neglected in a review article. It should be considered that QUS methods differ in the site of skeletal measurement and then in its structure, and in the examined QUS parameters, some of which are more appropriate for estimating bone mineral status (eg, phalangeal bone transmission time that excludes the influence of soft tissues).2 Moreover, large reference databases are available for phalangeal QUS according to the main auxologic features.2,3 Furthermore, phalangeal QUS is poorly influenced by bone size 3 compared with calcaneal QUS and DXA, and it is able to assess fracture risk in children with bone and mineral disorders.4 I agree with the authors that peripheral quantitative computed tomography is the more accurate method to assess BMD, but it is not applicable in infants and in very small children; it exposes the child to x-ray even if the radiation is low, and it is not diffused. On the contrary, phalangeal QUS may be used in newborns (also in preterm infants); the method is radiation-free, and it is more diffused. Moreover, there are valuable and growing clinical experiences. In conclusion, phalangeal QUS should be considered a valid method to estimate bone mineral status in infants, children, and adolescents. Giampiero I. Baroncelli, MD Department of Reproductive Medicine and Pediatrics Division of Pediatrics University of Pisa Pisa, Italy 10.1016/j.jpeds.2006.01.012
REFERENCES 1. Specker BL, Schoenau E. Quantitative bone analysis in children: current methods and recommendations. J Pediatr 2005;146:726-31. 2. Barkmann R, Rohrschneider W, Vierling M, Troger J, de TF, Cadossi R, et al. German pediatric reference data for quantitative transverse transmission ultrasound of finger phalanges. Osteoporos Int 2002;13:55-61. 3. Baroncelli GI, Federico G, Bertelloni S, de Terlizzi F, Cadossi R, Saggese G. Bone quality assessment by quantitative ultrasound of proximal phalanxes of the hand in healthy subjects aged 3 to 21 years. Pediatr Res 2001;49:713-8. 4. Baroncelli GI, Federico G, Bertelloni S, Sodini F, De Terlizzi F, Cadossi R, et al. Assessment of bone quality by quantitative ultrasound of
704
proximal phalanges of the hand and fracture rate in children and adolescents with bone and mineral disorders. Pediatr Res 2003;54:125-36.
Reply To the Editor: We are grateful for Dr Baroncelli’s comments on the utility of quantitative ultrasound (QUS) for examining skeletal development in children and adolescents. We agree that a significant amount of publications have presented QUS data, both in healthy children and in various pediatric bone disorders. However, the main purpose of our review was to point out strengths and weaknesses of the various methods to examine skeletal development and to highlight the necessity for further improvements. QUS has major limitations in that this technique does not allow distinguishing between bone mass, density, and geometry. Skeletal development is characterized by concomitant changes in these parameters. If we aim at a deeper understanding of the physiology and pathophysiology of bone development, we need methods that analyze bone mass, density, and geometry separately. There is no doubt that the lack of radiation exposure makes ultrasound methods attractive at first glance. Unfortunately, this advantage comes at the price of ill-defined analytical results. It is also important to re-emphasize that the results of many QUS methods depend on bone size (and thus body height). In contrast to Dr Baroncelli’s statement on this matter, some authors have found that this is also true for phalangeal QUS.1,2 We also believe that Dr Baroncelli’s conclusion is overly optimistic. Eckhard Schönau Children’s Hospital, University of Cologne D-50924 Köln, Germany Bonny Specker, PhD E. A. Martin Program in Human Nutrition, South Dakota State University, Brookings, SD 57007 10.1016/j.jpeds.2006.02.008
REFERENCES 1. Schönau E. Problems of bone analysis in childhood and adolescence. Pediatr Nephrol 1998;12:420-9. 2. Fricke O, Tutlewski B, Schoenau E. Speed of sound: relationship to geometrical characteristics of bone in children adolescents and adults. J Pediatr 2005;146:764-8.
Evidence-based protocols for oral NSAID challenges To the Editor: Debley et al interpret their data as indicating that ⬎100,000 asthmatic children are at risk for bronchospasm from ibuprofen.1 We disagree and believe their study did not The Journal of Pediatrics • May 2006