Confined Compression of Bone Substitute Granules
This study investigated the strength of several bone graft substitute (BGS) granular products under compression in a confined fixture characteristic of packing into a contained surgical bone defect. The compressive strength values for columns of granules made of tricalcium phosphate (TCP, dense), calcium carbonate / hydroxyapatite (CC/HA, porous) and ultraporous TCP (TCPu, ultra porous) were 2063.8 ±177.6N, 115.3 ±7.4N, and 40.5 ±8.3, respectively. As a result of their higher strength, the TCP granules did not appreciably reduce in volume after packing. The CC/HA and TCPu granules appreciably reduced in volume after packing, with the final packed volumes being 68% and 41%, respectively, of their original volumes. Based on these results the TCP synthetic bone substitute granules are better able to resist crushing and retain their original volume and osteoconductive capacity during packing in a bone defect than the other BGS granules tested in this study. These properties give the dense granules with a six-arm, interlocking shape superior robustness during handling and implantation compared to other BGS scaffolds produced by porous granules, morsels or blocks, while producing a comparable osteoconductive, resorbable scaffold with interconnected porosity.
Panjian Li, Kai Zhang and Clifford W. Colwell, Jr.
M. Long et al., "Confined Compression of Bone Substitute Granules ", Key Engineering Materials, Vols. 284-286, pp. 361-364, 2005