New standards of cortical mass in the humerus of neonates: a means of evaluating bone loss in the premature infant.

The purpose of this study was to develop standards for quantitating bone loss in premature infants. Cortical measurements of the humerus, including the outside diameter (T), the inner diameter (M), the cortical thickness (C), and the cortical area (CA), were calculated for 132 newborn infants who weighed between 500 and 3,686 g and ranged in gestational age from 22 to 40 weeks. The measurements were correlated with the independent variables of gestational age and birth weight, and are presented graphically. With the method of cortical measurement described in this study, it may be possible to determine the causes of bone loss, and to find ways to correct it.