Bone Tissue Properties after Lanthanum Zirconate Ceramics Implantation: Experimental Study

Background. The ceramic based on lanthanum zirconate is characterized by optimal mechanical characteristics, low corrosion potential and the absence of cytotoxicity. Thus, the possibility of its use as bone substituting material is currently studied.The purpose of the studywas to determine the mechanical, morphological and x-ray spectral characteristics of bone tissue after implantation of ceramic material based on lanthanum zirconate.Materials and methods. The experiment was conducted on 27 female guinea pigs of a single line, divided into 3 groups of 9 animals each. In the main group (LZ), lanthanum zirconate rods were implanted. In the comparison group (b-TCP), fixation was performed with b-tricalcium phosphate rods. In the native control group (NC) no surgical procedures were performed. A fracture was created in distal metadiaphysis area of femur using open osteoclasia. Animals were hatched 4, 10, and 25 weeks after the start of the experiment. Bone tissue features were studied in the perifocal region. The following methods were used: uniaxial compression, scanning electron microscopy (SEM), energy dispersive x-ray microanalysis (EDxMA). The statistical analysis was performed using the Mann-Whitney test.Results. The architectonics of the newly formed bone in the LZ group appeared as a developed lacunar tubular network. The structural components of the extracellular matrix were oriented along the bone functional load vectors. The Ca/P ratio in the periimplant region of the bone in the LZ group was significantly higher than in the b-TCP and NC groups. This may indicate a high strength of the newly formed bone. Mechanical testing showed that the strength and performance of the system of “lanthanum zirconate – bone” under uniaxial compression exceeded the similar indicators in the b-TCP group.Conclusion. The synthesized new material based on lanthanum zirconate seems promising for use in traumatology and orthopedics. Although, additional studies are needed to optimize these implants integration into bone tissue.