Elsevier

Bone

Volume 26, Issue 2, February 2000, Pages 103-109
Bone

Original Articles
Normative data for iliac bone histomorphometry in growing children

https://doi.org/10.1016/S8756-3282(99)00257-4Get rights and content

Abstract

Many insights into normal and pathologic bone development can only be gained by bone histomorphometry. However, the use of this technique in pediatrics has so far been hampered by the lack of reference data. Therefore, we obtained transfixing iliac bone samples from 58 individuals between 1.5 and 22.9 years of age (25 male; tetracycline labeling performed in 48 subjects), who underwent surgery for reasons independent of abnormalities in bone development and metabolism. The results of histomorphometric analyses of cancellous parameters and cortical width are presented as means and standard deviations, as well as medians and ranges in five age groups. In addition, the original data are available from the authors. There were significant age-dependent increases in both cortical width and cancellous bone volume, the latter being due to an increase in trabecular thickness. Osteoid thickness did not vary significantly with age. Bone surface-based indicators of bone formation showed an age-dependent decline, reflecting similar changes in activation frequency. Mineral apposition rate decreased continuously with age. Parameters of bone resorption did not vary significantly between age groups. Paired biopsies from adjacent sites, obtained in eight subjects, were used to examine the reproducibility of histomorphometric parameters in children. The lowest coefficients of variation (<10%) were found for structural measures, as well as mineral apposition rate and wall thickness. The highest variability was found for cellular parameters. The availability of reference material will greatly facilitate the use of histomorphometry in pediatrics.

Introduction

Despite the invasive character of the procedure, the inclusion of a bone biopsy in protocols aiming at the diagnosis and therapeutic follow-up of pediatric metabolic bone disease is progressively gaining ground. Because in the growing skeleton modeling and remodeling activities are high and likely change with age, it is critical to compare quantitative data obtained in a given patient with those from a proper control group. A number of detailed histomorphometric normative data pertaining to the mature and aging skeleton have been published during the last 20 years,6, 7, 10, 14, 19, 21 but data in children are scarce.

Several studies have presented some histomorphometric values of children without metabolic bone disease.1, 18, 20 Yet, in most cases, prior tetracycline labeling was not performed and therefore only static parameters could be measured. A larger collection of about 30 tetracycline labeled biopsies from healthy children between 2.5 and 18 years has served as a control group in various studies on pediatric bone diseases.5, 15, 16, 17 However, no reports on age changes in individual histomorphometric parameters during growth are available at present.

We thus undertook to harvest tetracycline-labeled transfixing iliac bone samples from a large group of children, who underwent surgery for reasons independent of abnormalities in bone development and metabolism. Our aim was to establish normative data for static and dynamic parameters of bone histomorphometry in discrete age groups spanning the whole growth period. The present report presents these normative data for use by others in the field. A detailed analysis of the implications of our results for bone physiology during growth will be published elsewhere.

Section snippets

Subjects

The study population comprised 58 healthy white subjects (25 males; age 1.5–22.9 years), in whom bone biopsies were obtained during surgery for various orthopedic conditions. In eight of these individuals, two adjacent bone cores were obtained. All subjects were ambulatory, had normal renal function as assessed by measurement of serum creatinine, and had no evidence of any metabolic bone disease. Orthopedic conditions included lower limb deformities (n = 14), scoliosis (n = 24), clubfeet (n =

Results

Figure 1 shows typical sections of biopsies from each age group. Table 1, Table 2, Table 3, Table 4 present mean and SD, as well as median and ranges of each parameter in the entire study population and in each age group. Cortical width (Ct.Wi) was lowest in the youngest group and then appeared to remain stable (Table 1). In contrast, cancellous bone volume (BV/TV) and mineralized bone volume (Md.V/BV) showed a steady increase, which was mostly due to an increase in trabecular thickness

Discussion

Although indirect methods to evaluate bone mass and metabolism have gained widespread popularity in recent years, many insights into normal and pathologic bone development can only be gained by bone histomorphometry. However, the use of this technique in children has so far been hampered by the lack of reference data. In the present study, we try to fill this gap by providing histomorphometric results of iliac crest biopsies that were obtained from children and adolescents without metabolic

Acknowledgements

The authors thank Dr. R. Weinstein and Dr. R. Recker for their helpful comments in the earlier stages of this project. We also thank Guy Charette for technical assistance with sample processing and Mark Lepik for artwork. This study was supported by the Shriners of North America and by the Deutsche Forschungsgemeinschaft (Grant Ra 803/1-1).

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