Article
Pathophysiology of cranial suture synostosis is expressed by altered temporal sequences: 2D-histomorphometry, bone mineral density distribution and energy dispersive X-ray analysis in normal and pathological human sutures
Search Medline for
Authors
-
B. Busse
- Institut für Osteologie und Biomechanik, Universitätsklinikum Hamburg-Eppendorf, Hamburg
-
T. Schmidt
- Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Hamburg-Eppendorf, Hamburg
-
M. Hahn
- Institut für Osteologie und Biomechanik, Universitätsklinikum Hamburg-Eppendorf, Hamburg
-
C. von Domarus
- Institut für Osteologie und Biomechanik, Universitätsklinikum Hamburg-Eppendorf, Hamburg
-
M. Tsokos
- Institut für Gerichtsmedizin und Forensische Wissenschaft, Charité - Universitätsmedizin Berlin, Berlin
-
M. Amling
- Institut für Osteologie und Biomechanik, Universitätsklinikum Hamburg-Eppendorf, Hamburg
-
J. Regelsberger
- Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Hamburg-Eppendorf, Hamburg
| Published: | April 28, 2011 |
|---|
Outline
Text
Objective: Premature fusion of cranial sutures is known to be associated with mutations of several transcription and growth factors, leading to an accelerated bone growth at the intermembranous gaps. Apart from signalling in craniosynostosis, studies on the bony structure and bony contents of normal and pathological sutures in humans were expected to give us further information about suture morphogenesis.
Methods: Microarchitecture and suture content analyses from normal cranial sutures (n=5) as well as from pathological sutures (n=5) between the age of three and twelve months were carried out. Comparisons of the osseous structure of the adjacent bony plates of normal and pathological sutures were performed by static 2D-histomorphometry and bone mineral density distribution analyses (BMDD) by quantitative backscattered electron imaging. Spectra of energy dispersive x-ray analyses (EDX) were utilized to investigate the unmineralized suture content.
Results: 2D-histomorphometric assessment of structure parameters (BV/TV, Tb.Th., Tb.N., and Tb.Sp.) and osteoid indices (O.Th., OV/BV, and OS/BS.) in the adjacent bony plates alongside normal sagittal, coronal and lamdoid sutures revealed no distinctive features. EDX microanalyses of the fused and non-fused segments showed no differences in elemental compositions, whereas significantly increased levels of hydroxyapatite component calcium (Ca) as well as sulphur (S) were found in normal and synostotic suture margins in comparison to their unmineralized suture centers. Analyses of BMDD in normal and synostotic sutures showed comparable values in the mean calcium content (mean Ca Wt%) of the bony plates, whereas in synostotic sutures the heterogeneity in mineralization was significantly decreased. In fused segments, reduced calcium width (Ca Wt% width) is associated with a decrease of woven bone packets due to advanced remodelling in favor of the formation of primary osteons.
Conclusions: Suture synostosis with significantly decreased inhomogeneity of mineralization areas can be interpreted as a sign of completed ossification. Thus non-fused segments of synostotic sutures showed no structural and elemental differences in the bony and sutural contents compared to normal sutures. In conclusion, our data seems to emphasize the theory of a dynamic fusion process in suture synostosis commencing just too early.
