gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017)

24.10. - 27.10.2017, Berlin

Raman microscopic study of osteonecrosis of the femoral head

Meeting Abstract

  • presenting/speaker Stefan Landgraeber - Universitätsklinikum Essen, Klinik für Orthopädie und Unfallchirurgie, Essen, Germany
  • Matthias König - Molekulare Biophotonik und Nanodiagnostik, Universität Duisburg-Essen, Essen, Germany
  • Sebastian Warwas - Universitätsklinikum Essen, Klinik für Orthopädie und Unfallchirurgie, Essen, Germany
  • Marcus Jäger - Universitätsklinikum Essen, Klinik für Orthopädie und Unfallchirurgie, Essen, Germany
  • Sebastian Schlücker - Molekulare Biophotonik und Nanodiagnostik, Universität Duisburg-Essen, Essen, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017). Berlin, 24.-27.10.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocPO30-941

doi: 10.3205/17dkou891, urn:nbn:de:0183-17dkou8916

Veröffentlicht: 23. Oktober 2017

© 2017 Landgraeber et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: The aetiology and pathogenesis of osteonecrosis of the femoral head (ONF) remains unclear. Structural changes in the bone induced by hypoperfusion, in particular, have still not been fully explained. Characterisation of osteonecrotic bone using Raman spectroscopy could shed light on the changes that take place in its composition. This study focuses on investigation of changes in the carbonate and phosphate content of osteonecrotic bone.

Methods: So far, six femoral heads from patients with ONF have been examined. Samples were taken from the necrotic part (nP-ONF) and the healthy part (hP-ONF) of the heads. Four samples from patients without ONF (w-ONF) served as a control group. All samples were harvested during hip replacement surgery and examined directly after the operation without previous preparation in a fixation medium. Suitable areas for measurement were determined using bright-field microscopy and then certain given points were characterised by Raman mircoscopy.

Results and Conclusion: Comparison of Raman spectra recorded of necrotic bone (nP-ONF: ACarbonate/APhosphate = 0.20±0.04) with those recorded of healthy bone (hP-ONF: ACarbonate/APhosphate = 0.28±0.05) show that peak area ratio (carbonate to phosphate) of necrotic bone decreases, caused by a lower proportion of carbonate. Comparing all groups the samples from patients without ONF (w-ONF: ACarbonate/APhosphate = 0.37±0.05) have the highest proportion of carbonate in relation to phosphate.

Up to now the results of the study therefore indicate that characterisation of ONF by Raman spectroscopy offers great potential for evaluation of changes in the inorganic structure of bone caused by necrosis. To enhance the significance of this finding concerning the changed composition of bone, the measurements made at specific given points will be supplemented by further examination of microscopic areas using Raman mapping. Microscopically defined areas of 50µm x 50µm will be scanned by recording of 2,500 single Raman spectra. In comparison with point measurements, the use of multiple spectra has the advantage that representative and non-representative proportions can be more accurately averaged, which enables more reliable statistical evaluation.

If these additional measurements confirm the relative deficiency of carbonate ions in relation to phosphate ions, this would be a highly relevant finding. Firstly, it would explain why and how the biomechanical properties of bone change, and secondly, this knowledge could be important for early diagnostics and therapy. Currently, more samples are being harvested and examined to further validate this observation.