1+2/2010 - Společnost pro pojivové tkáně

ecular microstructure respect to controlgroup. However FK 506 treatment produceda high decrease in both lumbarand femoral BMD, and negative effect infemoral trabecular microstructure. RAPAtreatment damages significantly the femoralcortical structure and the femoral BMD,without changes in trabecular bone microstructureand lumbar BMD.Poznámky: tyto léky se aplikují a uplatňujípo transplantačních operacích s cílemdocílit nárůst kostní hmoty. Rozdílný jeúčinek na trabekulární a kortikální kost,redukují kortikalis, ale ne trabekulární kost.RISEDRONATE REDUCESINTRACORTICAL POROSITY INWOMEN WITH OSTEOPOROSISB. Borah et al. (Mason, Boston – USA,Melbourne – Australia)Porosity is a manifestation of corticalremodeling resulting in secondary osteonswith central vascalar Haversian canalsand has important ramifications for bonestrength and fractures and their accompayingmorbidity and mortality. Despitethis, the effect of drug therapy on corticalmorphology has received limited attention,partly because cortical bone is believedto remodel less and decrease less withage than trabecular bone. However, haversiancanals traversing the cortex providea surface for remodeling which producesbone loss, porosity and fragility.In the risedronate group, porositydecreased from baseline during 5 yearsof treatment, corresponding to an 18 to25 % reduction and remained unchangedin the placebo group across all pore sizes.Porosity at 5 years in the 25–100 mm rangewas lower by 17 % in the risedronate thanthe placebo group. Pore number per unitbone area in the 25–. 100 mm range wasalso lower by 17 % at 5 years in the risedronatethan placebo group.Risedronate reduces bone remodelingand so reduces the area and numberof pores. The reduced intracortical porositywith risedronate is likely to contributeto the slowing of progession and perhapspartial reversal of fragility, which reducesfracture risk.Poznámky: 80 % veškerých fraktur skeletujsou fraktury vertebrální. Při teoretickýchrozborech mechanismů fraktur semusí zohlednit Parfittův zákon a matematickémodelování vnitřní strukturyosteonu. Existuje velká variabilita v měřeníporozity skeletu v jednotlivých studiícha to i u jednoho autora či pracovníhotýmu, což relativizuje závěry těchto měření.Ve studiích fraktur musíme oddělit trabekulárnía kortikální kompartment. Důležitéjsou percentuální údaje o počtu pórů.COMPARISON AND COMBINATIONOF DIFFERENT METHODS FORDESCRIPTION OF GLOBALAND LOCAL FEATURES OF THETRABECULAR NETWORKSidorenko, I. et al. (Mnichov, SRN)A proper description of the global andlocal structural characteristics of the trabecularnetwork, which plays the main role inload carrying and distribution of cancellousbone, helps to evaluate deteriorationof bone tissue caused by osteoporosisand to predict the most frequent complicationsof this disease, namely spine and hipfractures.The scaling index method SIM quantifiedbone structure on a local level by118LOCOMOTOR SYSTEM vol. 17, 2010, No. 1+2