AN ATTEMPTED CORRELATION OF MECHANICAL PROPERTIES OF BONE WITH ANTIRACHITIC HEALING AND WITH MOLECULAR STRUCTURE AS DETERMINED BY X-RAY DIFFRACTION TECHNIC

Abstract

When examined by x-ray diffraction technic, the cortices of the tibiae of albino rats show characteristic preferred orientation on the long axis of the bones, in confirmation of the reports of several earlier investigators. This orientation is most pronounced in the plane having a lattice spacing of 3.43 A.U. and corresponds to the 5th ring in the type pattern of powdered apatite. The identity of bone salts with apatite is confirmed by the finding of nearly identical powder diffractograms of bone and apatite. Disorientation occurs in rickets and appears to be largely irreparable. Disorientation in rickets bears no direct relation to the ability of bones to resist mechanical stress since bones of rachitic rats may be re- stored but disorientation is not repaired completely in 275 days on an antirachitic diet. The preferred orientation of normal bone is disrupted by many physiological and pathological influences. Whether disorientation has any physiological significance other than as an indicator of a type of metabolic disturbance cannot be detd. at present.