The incorporation of fluoride and strontium in hydroxyapatite affects the composition, structure, and mechanical properties of human cortical bone.
Strontium ranelate and fluoride salts are therapeutic options to reduce fracture risk in osteoporosis. Incorporation of these elements in the physiological hydroxyapatite matrix of bone is accompanied by changes in bone remodeling, composition, and structure. However, a direct comparison of the effectiveness of strontium and fluoride treatment in human cortical bone with a focus on the resulting mechanical properties remains to be established. Study groups are composed of undecalcified specimens from healthy controls, treatment-naïve osteoporosis cases, and strontium ranelate or fluoride-treated osteoporosis cases. Concentrations of both elements were determined using instrumental neutron activation analysis (INAA). Backscattered electron imaging was carried out to investigate the calcium content and the cortical microstructure. In comparison to osteoporotic patients, fluoride and strontium-treated patients have a lower cortical porosity indicating an improvement in bone microstructure. Mechanical properties were assessed via reference point indentation as a measure of bone's resistance to deformation. The strontium-incorporation led to significantly lower total indentation distance values compared to osteoporotic cases; controls have the highest resistance to indentation. In conclusion, osteoporosis treatment with strontium and fluoride showed positive effects on the microstructure and the mechanical characteristics of bone in comparison to treatment-naïve osteoporotic bone. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 433-442, 2017.
Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestrasse 55A, Hamburg, 22529, Germany.
Christoph
C
Riedel
Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestrasse 55A, Hamburg, 22529, Germany.
Elizabeth A
EA
Zimmermann
Department of Pathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20246, Germany.
Jozef
J
Zustin
Institute of Experimental Physics, University of Hamburg, Luruper Chaussee 149, Hamburg, 22761, Germany.
Manfred
M
Niecke
Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestrasse 55A, Hamburg, 22529, Germany.
Michael
M
Amling
Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 25 Orde Street, Toronto, Ontario, M5T 3H7, Canada.
Marc
M
Grynpas
Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestrasse 55A, Hamburg, 22529, Germany.
Björn
B
Busse
D000328:Adult; D000368:Aged; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology; D017886:Durapatite / Q000008:administration & dosage / Q000493:pharmacokinetics; D005260:Female; D005459:Fluorides / Q000008:administration & dosage / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D013876:Thiophenes / Q000008:administration & dosage / Q000493:pharmacokinetics
D013876:Thiophenes; C081587:strontium ranelate; D017886:Durapatite; D005459:Fluorides
biomechanics; biomineralization; fluorapatite; hydroxyapatite; strontium apatite