Computer Aided Stereometric Evaluation of Porostructuralosteoconductive Properties of Intra-Osseous Implant Porous Coatings

Abstract

The proper interaction of bone tissue -the natural porous biomaterial -with a porous coated intra-osseous implant is conditioned, among others, by the implant porous coating poroaccessibility for bone tissue adaptive ingrowth. The poroaccessibility is the ability of implant porous coating outer layer to accommodate the ingrowing bone tissue filling in its pore space and effective new formed bone mineralizing in the pores to form a biomechanically functional bone-implant fixation. The functional features of the microtopography of intra-osseous implant porous surfaces together with the porosity of pore space of the outer layer of the porous coating are called by bioengineers the porostructural-osteoconductive properties of the porous coated implant. The properties are crucial for successful adaptive bone tissue ingrowth and further long-term (secondary) biomechanical stability of the boneimplant interface. The poroaccessibility of intra-osseous implants porous coating outer layers is characterized bythe introduced in our previous papers -set of stereometric parameters of poroaccessibility: the effective volumetric porosity I Vef , the index of the porous coating space capacity V PM , the representative surface porosity I Srep , the representative pore size p Srep , the representative angle of the poroaccessibility :rep and the bone-implant interface adhesive surface enlargement index \. Presented in this paper, an original method of evaluation of the porostructural-osteoconductive properties of intra-osseous implant porous coatings outer layer by means of the parameters of poroaccessibility was preliminary verified during experimental tests performed on the representative examples of porous coated femoral stems and acetabular cups of various hip endoprostheses. The computer-aided stereometric evaluation of the microstructure of implant porous coatings outer layer can be now realized by the authoring application software PoroAccess_1.0 elaborated in our research team in Java programming language.

Structural-Geometric Functionalization of the Additively Manufactured Prototype of Biomimetic Multispiked Connecting Ti-Alloy Scaffold for Entirely Noncemented Resurfacing Arthroplasty Endoprostheses

“…Increase in the effective height H ef of SLM-manufactured spikes of the MSC-Scaffold directly translates into the enlargement of its adhesive properties. In accordance with the conclusions presented in work [ 28 ] and Rogala's patent assumptions [ 8 – 10 ], the parameter assessing the adhesive surface enlargement of the MSC-Scaffold is crucial for determination of the structural conditions for bone-implant interactions. Its linear dependence to the effective height H ef of the MSC-Scaffold spikes has been revealed in [ 29 ].…”

“…Concluding the above, and also taking into account findings regarding the interrelations between the poroaccessibility parameters describing the porous coating outer layers indicated in papers [ 27 , 28 ], enables us to assume that, in the case of the MSC-Scaffold, the parameters proposed as their equivalents can be used interchangeably as adequate. Therefore, the “poroaccessibility” of the MSC-Scaffold and, consequently, the structural-geometric pro-osteoconduction potential of the MSC-Scaffold is dependent on the effective height H ef of spikes and the representative interspike distance D is-rep .…”

“…Our previous findings, dealing with implant porous coatings [ 27 , 28 ], showed that the poroaccessibility parameter set characterizes major aspects of the morphological features of the outer layer of porous coatings, including those describing the spatial, volumetric, hybrid, and functional properties of the implant surface. In Table 1 , the set of parameters for characterization of the poroaccessibility of the intraosseous implant porous coating outer layers [ 23 – 26 ] is presented, and the proposal for the equivalent parameters recommended for determination of the structural-geometric pro-osteoconduction potential of the MSC-Scaffold prototype design is given.…”