Bone microarchitecture of the calcaneus and its changes in aging: a histomorphometric analysis of 60 human specimens.
ABSTRACT Bone structure and quality are an important parameter in the propensity of bone to fracture. Although the calcaneus is used as diagnostic reference site for osteoporosis by ultrasound, its structure has never been analyzed in detail. The purpose of this study was therefore to histomorphometrically analyze the trabecular microarchitecture of the calcaneus, and to determine whether the calcaneal bone structure is changing with age. Sixty complete human calcanei were harvested from thirty age- and gender-matched patients at autopsy. Each of the three different age groups (group I: 20 to 40, group II: 41 to 60, group III: 61 to 80 years of age) was represented by 20 specimens. The specimens were subjected to radiographic, microCT, and histologic analysis. Bone structure and bone mass of the calcaneus were quantified for three different regions of interest: the anterior ROI, the superior ROI (the subtalar region under the posterior facet), and the posterior ROI. An iliac crest biopsy was obtained from all patients to exclude any metabolic bone disease. Histomorphometric analysis revealed significant differences in bone volume within the calcaneus with highest values in the superior ROI: age group I: 31.3% (27.8-34.8%); II: 25.5% (22.1-28.9%); III: 18.9% (16.6-21.2%) and lowest bone volumes in the anterior ROI; age group I: 6.2% (4.8-7.6%); II: 3.6% (2.1-5.1%); III: 3.9% (2.9-4.9%). There was a significant age-related decrease in bone volume (BV/TV) in aging. Interestingly, this bone loss was most prominent in the superior ROI, with a 39% decrease in BV/TV between age group I and III (p < 0.001). Qualitative and structural analysis of trabecular number, thickness, and spacing demonstrated that the bone loss in the thalamic portion of the calcaneus was due to the transition of plate-like trabecular elements into a rod-like structure. In conclusion, our study demonstrated that the calcaneus displayed age-related changes in its microarchitecture that are known to reduce the biomechanical stability of trabecular bone, and that the age-related bone loss was most prominent in the region adjacent to the posterior facet (superior ROI). These results suggest that bone mass and structure are risk factors in respect to the occurrence and severity of calcaneal fractures, and indicate that calcaneal fractures are at least in part osteoporotic fractures.
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ABSTRACT: In a prospective cohort of 7,598 women aged 75 and over, we analyzed the effect of age on the ability of femoral neck bone mineral density (BMD) and of ultrasound (BUA and SOS) of the calcaneus to predict hip fracture. Unadjusted regression analysis showed that the risk of hip fracture was increased 1.7 times for one standard deviation increase in age (3.7 years). Overall, for a decrease of one standard deviation in quantitative bone measures, the risk was significantly increased by 2.2 times for BMD (1.9-2.5), 1.8 for BUA (1.6-2.1), and 1.9 for SOS (1.6-2.2). However the average relative risk associated with a decrease in BMD tends to diminish with advancing age, meaning that a smaller part of the risk is explained by BMD in the very elderly. This is confirmed by the areas under the ROC curves (AUC) of BMD that are significantly better before 80 years (0.75 [0.73-0.76]) than after (0.65 [0.63-0.67] in group 80-84 years and 0.65 [0.61-0.68] in group >/=85). On the other hand, as the absolute risk increases exponentially with age, the number of hip fractures attributable to a low BMD is still important in the very elderly, the risk difference between the lowest and the highest quartile of BMD is 25 hip fractures / 1,000 woman-years in the group >/=85 compared with 16 in the two other groups. Thus, after 80, quantitative assessment of bone may still be of interest for clinical decisions. Compared with quantitative ultrasound parameters, the ability of BMD to predict hip fracture was significantly superior to that of BUA and SOS only before the age of 80 (AUC of BMD 0.75 [0.73-0.76], BUA 0.67 [0.66-0.69], SOS 0.67 [0.65-0.69]). For patients older than 80, we did not observe significant differences in AUC between DXA and QUS to predict hip fracture.Osteoporosis International 03/2004; 15(3):196-203. · 4.04 Impact Factor
- Calcified Tissue International 06/1982; 34(3):311. · 2.50 Impact Factor
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ABSTRACT: The aim of the study is to correlate the CT-morphological changes of fractured calcaneus and the classifications of Zwipp and Sanders with the clinical outcome. In a retrospective clinical study, the preoperative CT scans of 75 calcaneal fractures were analysed. The morphometry of the fractures was determined by measuring height, length diameter and calcaneo-cuboidal angle in comparison to the intact contralateral side. At a mean of 38 months after trauma 44 patients were clinically followed-up. The data of CT image morphometry were correlated with the severity of fracture classified by Zwipp or Sanders as well as with the functional outcome. There was a good correlation between the fracture classifications and the morphometric data. Both fracture classifying systems have a predictive impact for functional outcome. The more exacting and accurate Zwipp classification considers the most important cofactors like involvement of the calcaneo-cuboidal joint, soft tissue damage, additional fractures etc. The Sanders classification is easier to use during clinical routine. The Zwipp classification includes more relevant cofactors (fracture of the calcaneo-cuboidal-joint, soft tissue swelling, etc.) and presents a higher correlation to the choice of therapy. Both classification systems present a prognostic impact concerning the clinical outcome.Zeitschrift für Orthopädie 140(3):339-46. · 0.86 Impact Factor