Ut. Iwaniec et Td. Crenshaw, DISTRIBUTION OF MINERALIZATION INDEXES OF MODELING AND REMODELING OVER 8 MONTHS IN MIDDIAPHYSEAL GROSS SECTIONS OF FEMURS FROM ADULT SWINE, The Anatomical record, 250(2), 1998, pp. 136-145
Background: This study assessed the distribution of active mineral for
mation sites within the middiaphyseal femoral cross section of swine a
nd determined the extent to which various subsections represented bone
formation activity in the entire cross section, Methods: Twenty adult
female swine (sows) were injected with two double (10-day intervals)
labels 8 months apart, Labels involved fluorochrome markers of active
mineral formation sites, Intact femoral middiaphyseal cross sections w
ere embedded in polymethylmethacrylate, cut, and ground to 80 mu m for
analysis, Each specimen was subdivided into 16 anatomical and eight g
eometric subsections, Labeled mineralizing surface and mineral apposit
ion rate were determined in the periosteal and endocortical envelopes,
The number of labeled osteons per unit area of bone and osteonal mine
ral apposition rate were determined in the intracortical envelope. Res
ults: Periosteal mineralizing surface followed a bimodal distribution
with highest surface activation on the anterior and posterior segments
, Periosteal mineral apposition rate followed a modal distribution wit
h highest apposition rates in the posterior portion of the cross secti
on, The distribution of forming osteons was modal with highest frequen
cies of labeled osteons in the posterior segment, No significant regio
nal differences were detected for osteonal mineral apposition rate, en
docortical mineralizing surface, or endocortical mineral apposition ra
te, The location of either a single or a combination of two to four su
bsections that best predicted mineralizing surface and mineral apposit
ion rate in the entire cross section differed with each trait and enve
lope, Fifty percent of the entire area as alternate anatomical subsect
ions was required to predict >90% of variation in all traits evaluated
, Overall, the predictability of mineralizing surface and mineral appo
sition rate was similar for geometrically defined subsections, Conclus
ion: At least 50% of the cross-sectional area from alternate anatomica
l subsections must be measured to predict >90% of variation in periost
eal, intracortical, and endocortical mineralizing surface and mineral
apposition rate in the sow middiaphyseal femur. (C) 1998 Wiley-Liss, I
nc.