Bone and Soft Tissues Integration in Porous Titanium Implants (Experimental Research)

Abstract

Aim. It’s common that revision arthroplasty of the large joints demands replacing of bone defects of irregular geometrical shapes and simultaneous restoring of support ability and ability to integrate surrounding muscular and tendinous structures into an implant that is required for a complete restoration of joint function.The purpose.To experimentally study the process of integration for muscular and bone tissue as well as tendinous and ligamentous structures into porous titanium materials.Material and methods. During in vivo experiment the authors created a standardized bone defect in 6 rabbits of chinchilla breed at the point of patella ligament attachment as well as a delamination area of muscular tissue in latissimus dorsi. Both knee joints and both latissimus dorsi were used in each animal. Study group included titanium implants with three-dimensional mesh structure. Control group — solid titanium implants with standard porosity. Titanium implants were produced by additive technologies with preliminary prototyping. The porosity corresponded to trabecular metal, striations — 0.45, pores size —100–200 microns. Study and control components were implanted in the identical conditions into the corresponding anatomical sites. Postoperative AP and lateral roentgenograms of knee joints were performed for all animals. Morphological research was conducted on day 60 after the implantation and strength properties were studied at day 90 after the implantation.Results.The authors observed bony ingrowth into implant pores with minimal volume of fibrous tissue, a distinct connective integration was reported represented by a dense fibrous tissue in the pores of components implanted into the muscular tissue. Testing of fixation strength of the study implants demonstrated a clearly superior strength of soft and bone tissue integration into the experimental mesh implants produced using additive technologies.

Biocompatibility and Osseointegration of Calcium Phosphate-Coated and Non-Coated Titanium Implants with Various Porosities

“…Researchers have different opinions regarding the optimal pore size for better osseointegration. Tikhilov et al [ 5 ] investigated bone and soft tissue integration of porous titanium implants with a pore size of 100–200 μm. Such products promoted bone ingrowth to a depth of 2–3 mm and provided good fixation of the implant.…”

“…Titanium has high strength and good biological compatibility with tissues during implantation [2,3]. Individual implants made of titanium and its alloys by 3D printing allow repairing complex bone defects as they have overall open porosity and offer the possibility to regulate the size and shape of pores during the manufacturing process [2][3][4][5][6]. Experimental repair of a unicortical diaphyseal femoral defect in animals showed high biodegradability and osteoconductive properties of 3D porous material based on calcium phosphate [7].…”