Alterations in X-Ray Diffraction Pattern of Rat Tibia in Rickets. ∗

Abstract

The use of diffractograms in the study of molecular structure has been discussed extensively by Clark. 1 Numerous studies on bone by this technic have confirmed that there is a characteristic pattern most nearly agreeing with the type pattern of dahlite. Not many reports have given consideration to the possibility that this characteristic pattern may undergo physiological alteration. Roseberry, Hastings and Morse 2 described briefly some age changes in cultures of osseous tissue. Clark and Mrgudich 3 described characteristic changes in rickets, quantitatively related to the degree of severity.

There was no fundamental change in chemical composition, since the lattice spacings were not altered. Both inorganic and organic elements were disorganized as evidenced by the much darker central area with its sharply defined boundaries and by the extension of the orientation arcs, sometimes forming a complete circle.

Several other reports have been made of qualitative alterations in diffraction patterns of bones under various experimental conditions. 4

In an effort to study the influence of healed rickets on the subsequent behavior of bone, our laboratory first made a study of mechanical efficiency, already reported. 5 A summary of findings in the first 5 series of those experiments is presented in Table I. From this it will be seen that in all groups on a rachitic diet for 2-3 weeks, there were no significant differences in mechanical efficiency as manifested by breaking stress, regardless of the duration of the recovery period. Significant differences were seen only when the period of rachitic feeding was extended to 6 weeks.

These same bones were used in the present study. Sections of cortex were ground from the tibial mid-shaft adjacent to the point of fracture.