Strontium‐containing hydroxyapatite (Sr‐HA) bioactive cement for primary hip replacement: An in vivo study

Abstract

The purpose of this study was to evaluate the strontium-containing hydroxyapatite (Sr-HA) cement in primary hip replacement, using a rabbit model, and to investigate the histological findings at the cement-implant and bone-cement interfaces under weight-bearing conditions. Unilateral hip replacement was performed with Sr-HA cement or polymethylmethacrylate (PMMA) cement in rabbits and observations were made after 6 months. Good fixation between the Sr-HA cement and implant was observed. Osseointegration of the Sr-HA cement with cancellous bone was widespread. Many multinucleus cells covered the surface of the cement, and resorbed the superficial layer of the cement. By scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis, high calcium and phosphorus levels were detected at the interface with a thickness of about 10 microm. Intimate contact was also observed between the Sr-HA cement and cortical bone without fibrous layer intervening. The overall affinity index of bone on Sr-HA cement was (85.06 +/- 5.40)%, which is significantly higher than that on PMMA cement (2.77%+/- 0.49%). On the contrary, a fibrous layer was consistently observed between PMMA cement and bone, and PMMA cement evoked an inflammatory response and foreign body reaction in the surrounding bony tissues. Results suggested good bioactivity and bone-bonding ability of the Sr-HA cement under weight-bearing conditions.

Solubility of strontium-substituted apatite by solid titration

“…Sr10-HAp has been widely studied in vitro and used in vivo, in particular as the main inorganic phase for the preparation of bone cement [32]. Pure, fully substituted SrHAp is also of special interest as the limiting case.…”

Evaluation of the in vivo biocompatibility of hydroxyapatite granules incorporated with zinc ions

“…Animals from each group were grafted subcutaneously with their respective materials (HA or ZnHA), and subdivided on groups of 5 individuals to be sacrificed at different experimental times (7,14,21,28 or 60 days after grafting). The rational for analysis of new biomaterials implies the cytotoxicity evaluations 14 , followed by the determination of subcutaneous response and intra-bony biocompatibility, as preconized by ISO 10993-5 and -6, former one applied in the present study.…”

“…Another important characteristic of HA is the possibility of incorporation of other components, such as metallic ions, on its structure [4][5][6] , thus promoting alterations on important physicochemical properties with impact on the biological response to this biomaterial. Also, this substitution may include bioactive elements or ions, which could also modulate important events related to bone regeneration, as they are released from HA onto biological media 7 . In this context, Zinc ions may represent strong candidates for incorporation on bioactive materials.…”

Development and clinical trial of a novel bioactive bone cement

“…Therefore, for the cemented femoral component, there existed two interfaces, cement-prosthesis interface and bone-cement interface. Ni et al evaluated Sr-HA cement in primary hip replacement using a rabbit model for 6 months in which the histological findings at the cement-implant and bone-cement interfaces under weight-bearing conditions were investigated [20].…”

“…Some studies indicated that strontium could be localized in calcified bone and it has been associated with improvement of osteoporosis [17][18][19]. Furthermore, this bioactive bone cement has shown improved contact with living bone when compared to commercial PMMA cement [20,21]. Sr-HA bioactive bone cement was designed to have desirable properties for use in treatment of spinal osteoporotic fractures by vertebroplasty [15,22].…”