scholarly journals Calcium Phosphate Bone Graft Substitutes with High Mechanical Load Capacity and High Degree of Interconnecting Porosity

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3471 ◽  
Author(s):  
Hettich ◽  
Schierjott ◽  
Epple ◽  
Gbureck ◽  
Heinemann ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bone Graft ◽  
Bone Regeneration ◽  
Mechanical Stability ◽  
Mechanical Load ◽  
Load Capacity ◽  
Virtual Object ◽  
Acetabular Bone Defect ◽  
Scaffold Structure ◽  
Bone Graft Substitutes

Bone graft substitutes in orthopedic applications have to fulfill various demanding requirements. Most calcium phosphate (CaP) bone graft substitutes are highly porous to achieve bone regeneration, but typically lack mechanical stability. This study presents a novel approach, in which a scaffold structure with appropriate properties for bone regeneration emerges from the space between specifically shaped granules. The granule types were tetrapods (TEPO) and pyramids (PYRA), which were compared to porous CaP granules (CALC) and morselized bone chips (BC). Bulk materials of the granules were mechanically loaded with a peak pressure of 4 MP; i.e., comparable to the load occurring behind an acetabular cup. Mechanical loading reduced the volume of CALC and BC considerably (89% and 85%, respectively), indicating a collapse of the macroporous structure. Volumes of TEPO and PYRA remained almost constant (94% and 98%, respectively). After loading, the porosity was highest for BC (46%), lowest for CALC (25%) and comparable for TEPO and PYRA (37%). The pore spaces of TEPO and PYRA were highly interconnected in a way that a virtual object with a diameter of 150 µm could access 34% of the TEPO volume and 36% of the PYRA volume. This study shows that a bulk of dense CaP granules in form of tetrapods and pyramids can create a scaffold structure with load capacities suitable for the regeneration of an acetabular bone defect.

Integrating silicon/zinc dual elements with PLGA microspheres in calcium phosphate cement scaffolds synergistically enhances bone regeneration

2020 ◽  
Vol 8 (15) ◽  
pp. 3038-3049 ◽  
Author(s):  
Weiwei Liang ◽  
Min Gao ◽  
Jingsheng Lou ◽  
Yunyang Bai ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bone Graft ◽  
Bone Regeneration ◽  
Calcium Phosphate Cement ◽  
Bone Repair ◽  
Plga Microspheres ◽  
Bone Graft Substitutes ◽  
Osteogenic Factors

Integrating multiple pro-osteogenic factors into bone graft substitutes is a practical and effective approach to improve bone repair efficacy.

In Vitro and In Vivo Evaluation Of Calcium Phosphate Bone Graft Substitutes

2010 ◽  
Vol 654-656 ◽  
pp. 2065-2070
Author(s):  
Ho Yeon Song ◽  
Young Hee Kim ◽  
Jyoti M. Anirban ◽  
In Seon Byun ◽  
Kyung A Kwak ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bone Formation ◽  
Bone Graft ◽  
Cellular Proliferation ◽  
New Bone Formation ◽  
Hydroxy Apatite ◽  
Defect Sites ◽  
Bone Graft Substitutes

Calcium phosphate ceramics such as hydroxy apatite (HA), β-tricalcium phosphate (β-TCP) and bicalcium phosphate (BCP) have been used as a bone graft biomaterial because of their good biocompatibility and similarity of chemical composition to natural bones. To increase the mechanical and osteoconductive properties, the granules and spongy type porous bone graft substitutes were prepared by fibrous monolithic process and polyurethane foam replica methods, respectively. The pore sizes obtained using these approaches ranged between 100-600 µm. The cytotoxicity, cellular proliferation, differentiation and ECM deposition on the bone graft substitutes were observed by SEM and confocal microscopy. Moreover, the scaffolds were implanted in the rabbit femur. New bone formation and biodegradation of bone graft were observed through follow-up X-ray, micro-CT analysis and histological findings. After several months (2, 3, 6, 12 and 24 months) of implantation, new bone formation and ingrowths were observed in defect sites of the animal by CaP ceramics and 2 to 3 times higher bone ingrowths were confirmed than that of the normal trabecular bones in terms of total bone volume (BV).

scholarly journals Morphological and mechanical characterization of chitosan-calcium phosphate composites for potential application as bone-graft substitutes

2015 ◽  
Vol 31 (4) ◽  
pp. 334-342 ◽  
Author(s):  
Guilherme Maia Mulder van de Graaf ◽  
Andre Luis do Valle De Zoppa ◽  
Rodrigo Crispim Moreira ◽  
Sylma Carvalho Maestrelli ◽  
Rodrigo Fernando Costa Marques ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bone Graft ◽  
Potential Application ◽  
Mechanical Characterization ◽  
Bone Graft Substitutes

scholarly journals Primary Stability of Revision Acetabular Reconstructions Using an Innovative Bone Graft Substitute: A Comparative Biomechanical Study on Cadaveric Pelvises

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4312
Author(s):  
Federico Morosato ◽  
Francesco Traina ◽  
Ronja A. Schierjott ◽  
Georg Hettich ◽  
Thomas M. Grupp ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bone Graft ◽  
Mechanical Stability ◽  
Primary Stability ◽  
Collagen Matrix ◽  
Bone Graft Substitute ◽  
Biomechanical Study ◽  
Image Correlation ◽  
Order Of Magnitude ◽  
Acetabular Defects

Hip implant failure is mainly due to aseptic loosening of the cotyle and is typically accompanied by defects in the acetabular region. Revision surgery aims to repair such defects before implantation by means of reconstruction materials, whose morselized bone graft represents the gold standard. Due to the limited availability of bone tissue, synthetic substitutes are also used. The aim of this study was to evaluate if a synthetic fully resorbable tri-calcium phosphate-based substitute can provide adequate mechanical stability when employed to restore severe, contained defects, in comparison with morselized bone graft. Five cadaveric pelvises were adopted, one side was reconstructed with morselized bone graft and the other with the synthetic substitute, consisting of dense calcium phosphate granules within a collagen matrix. During the biomechanical test, cyclic load packages of increasing magnitude were applied to each specimen until failure. Bone/implant motions were measured through Digital Image Correlation and were expressed in terms of permanent and inducible translations and rotations. The reconstruction types exhibited a similar behavior, consisting of an initial settling trend followed by failure as bone fracture (i.e., no failure of the reconstruction material). When 2.2 Body Weight was applied, the permanent translations were not significantly different between the two reconstructions (p = 0.06–1.0) and were below 1.0 mm. Similarly, the inducible translations did not differ significantly (p = 0.06–1.0) and were below 0.160 mm. Rotations presented the same order of magnitude but were qualitatively different. Overall, the synthetic substitute provided adequate mechanical stability in comparison with morselized bone graft, thus representing a reliable alternative to treat severe, contained acetabular defects.

Calcium phosphate bone graft substitutes: Failures and hopes

2012 ◽  
Vol 32 (11) ◽  
pp. 2663-2671 ◽  
Author(s):  
Marc Bohner ◽  
Laetitia Galea ◽  
Nicola Doebelin
Keyword(s):  
Calcium Phosphate ◽  
Bone Graft ◽  
Bone Graft Substitutes
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