Efficacy of silicate-substituted calcium phosphate with enhanced strut porosity as a standalone bone graft substitute and autograft extender in an ovine distal femoral critical defect model

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.

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IN VIVO EVALUATION OF A NEW β-TRICALCIUM PHOSPHATE BONE SUBSTITUTE IN A RABBIT FEMUR DEFECT MODEL

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237215500283 ◽

2015 ◽

Vol 27 (03) ◽

pp. 1550028 ◽

Cited By ~ 1

Author(s):

Kam-Kong Chan ◽

Chia-Hsien Chen ◽

Lien-Chen Wu ◽

Yi-Jie Kuo ◽

Chun-Jen Liao ◽

...

Keyword(s):

Bone Graft ◽

Tricalcium Phosphate ◽

Bone Substitute ◽

Zealand White Rabbit ◽

Bone Substitutes ◽

Bone Graft Substitute ◽

Defect Model ◽

In Vivo Evaluation ◽

Rabbit Femur

Calcium phosphate ceramics, of a similar composition to that of mineral bone, and which possess the properties of bioactivity and osteoconductivity, have been widely used as substitutes for bone graft in orthopedic, plastic and craniofacial surgeries. A synthetic β-tricalcium phosphate, Osteocera™, a recently developed bone graft substitute, has been used in this study. To evaluate the affinity and efficacy of Osteocera™ as bone defect implant, we used a New Zealand white rabbit femur defect model to test the osteoconductivity of this new bone substitute. Alternative commercially available bone substitutes, Triosite® and ProOsteon500, were used as the control materials. These three bone substitutes show good biocompatibility, and no abnormal inflammation either infection was seen at the implantation sites. In the histological and histomorphometric images, newly formed bone grew into the peripheral pores in the bone substitutes. After six months implantation, the volume of bone formation was found to be 20.5 ± 5.2%, 29.8 ± 6.5% and 75.5 ± 4.9% of the potential total cavity offered by ProOsteon500, Triosite® and Osteocera™, respectively. The newly formed bone area within the femur defect section for Osteocera™ was significantly larger than ProOsteon500 and Triosite®. We concluded that Osteocera™ shows better bioresorbability, biocompatibility and osteoconductivity in the rabbit femur defect model.

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