A three-dimensional representation of linear growth and skeletal maturation

Traditional two-dimensional (2-D) growth charts do not distinguish between the effects of a particular pathology or therapy on skeletal maturation and the effects on linear growth. In this study, longitudinal data from two growth studies on children were analysed using a computer technique to produce a growth chart in three dimensions. The three-dimensional (3-D) surface of the graph represents both the linear growth and the skeletal maturation of the patients. If the height and the chronological and bone ages of an individual patient are plotted to give a line in 3-D space, the line can be compared with the 3-D surface of the graph. This permits qualitative assessment of the relative effect of a pathology or treatment on skeletal maturation as compared with linear growth. Quantitative assessment is also possible by expressing the data in polar coordinates. The technique can be applied to clinical trials as well as to individual patients.