X-ray diffraction studies on the lattice perfection of human bone apatite (Crista iliaca)

The lattice perfection of human bone apatite (iliac crest of 117 individuals aged 0-90 years) was systematically investigated by means of combined X-ray diffraction procedures--profile fitting and line-broadening analysis--correlated with age, sex, type of tissue (corticalis, spongiosa), and position (superior, middle, and inferior) for different crystallographic directions [length axis using reflection (002), basal plane by means of reflections (300), (210), and (310)]. Bone specimens within age group 0-30 were strongly affected by an increased crystallinity in the direction of the c-axis (domain size increasing by 5-7 nm, strain decreasing respectively), whereas in the direction of the a-axis crystallinity decreased significantly (domain size shortening by 5-7 nm, strain increasing respectively) in correlation with some heteroionic substitutions within the apatitic structure. Within age group 30-80 a certain balance seemed to exist between processes of ordering and disordering such that statistically only a slight increase of crystallinity within the basal plane was observed. Age as main fixed effect was highly significant for all investigated parameters. Crystallinity was well correlated with type of tissue (corticalis, spongiosa) in the direction of the length axis of the bone crystallite.