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

Abstract

The multispiked connecting scaffold (MSC-Scaffold) prototype, inspired by the biological system of anchorage of the articular cartilage in the periarticular trabecular bone by means of subchondral bone interdigitations, is the essential innovation in fixation of the bone in resurfacing arthroplasty (RA) endoprostheses. The biomimetic MSC‐Scaffold, due to its complex geometric structure, can be manufactured only using additive technology, for example, selective laser melting (SLM). The major purpose of this work is determination of constructional possibilities for the structural-geometric functionalization of SLM‐manufactured MSC‐Scaffold prototype, compensating the reduced ability—due to the SLM technological limitations—to accommodate the ingrowing bone filling the interspike space of the prototype, which is important for the prototype bioengineering design. Confocal microscopy scanning of components of the SLM‐manufactured prototype of total hip resurfacing arthroplasty (THRA) endoprosthesis with the MSC‐Scaffold was performed. It was followed by the geometric measurements of a variety of specimens designed as the fragments of the MSC-Scaffold of both THRA endoprosthesis components. The reduced ability to accommodate the ingrowing bone tissue in the SLM‐manufactured prototypes versus that in the corresponding CAD models has been quantitatively determined. Obtained results enabled to establish a way of compensatory structural‐geometric functionalization, allowing the MSC‐Scaffold adequate redesigning and manufacturing in additive SLM technology.

First Biomimetic Fixation for Resurfacing Arthroplasty: Investigation in Swine of a Prototype Partial Knee Endoprosthesis

“…To design of the MSC-Scaffold microstructure, the background regarding bone ingrowth in case of porous coatings [40–43] and three-dimensionally printed porous metal scaffolds [44] was followed. Since the original MSC-Scaffold differs from the above porous structures, the biomimetics in terms of the spikes' size adjustment to the intertrabecular space of the periarticular bone [45] and the spikes arrangement conditioning structural accessibility for ingrowing bone tissue was assessed by the approach proposed in [23]. The constructional features of the MSC-Scaffold allow for its unit loadability ca.…”

“…Recent investigations on the MSC-Scaffold prototype have included, among others, the examination of possibilities of modifying the interspike structural proosteoconductive potential of the SLM-manufactured MSC-Scaffold [23]. The most influential geometrical features of the MSC-Scaffold to ensure the closest-to-physiological load transfer in the peri-implant bone were determined in numerical simulations [24].…”

Bone Density Micro-CT Assessment during Embedding of the Innovative Multi-Spiked Connecting Scaffold in Periarticular Bone to Elaborate a Validated Numerical Model for Designing Biomimetic Fixation of Resurfacing Endoprostheses

“…For this state, what is crucial is the determination of the critical load not causing further embedding of MSC-Scaffold during physiological loading of the operated limb. We used bone density micro-CT assessment during the mechanical embedding test of the MSC-Scaffold prototype in periarticular bone to develop a validated FE model, and therefore determined the most appropriate geometric features of the MSC-Scaffold and their values in relation to the preliminary patented version [ 11 , 12 , 13 , 14 ]. Similar to other works dealing with numerical modelling of bone-implant mechanical problems [ 19 , 21 , 22 ], this work combined experimental and computational analyses to perform a validation of the developed numerical model; the study was developed within the framework of two research projects (no.…”

“…Our research group designed, developed, and prototyped, through bioengineering research, the essential innovation for a fixation method of RA endoprostheses components in periarticular trabecular bone by means of an innovative multi-spiked connecting scaffold (MSC-Scaffold) [ 9 , 10 , 11 , 12 ]. The MSC-Scaffold concept was proposed by a member (orthopaedic surgeon) of the research group [ 13 , 14 ].…”

Native Osseous CaP Biomineral Coating on a Biomimetic Multi-Spiked Connecting Scaffold Prototype for Cementless Resurfacing Arthroplasty Achieved by Combined Electrochemical Deposition

“…In contrast to traditional long-stem total hip replacement (THR) endoprostheses requiring surgical removal of the femoral head and neck, for the current generation of THRA endoprostheses, the femoral head is not removed, but is instead trimmed and capped with metal components fixed in subchondral bone with cement and a short stem placed in the femoral neck [1,2]. An essential innovation in the fixation technique for components of THRA endoprostheses in the periarticular trabecular bone—entirely cementless interfacing by means of the biomimetic multi-spiked connecting scaffold (MSC-Scaffold)—was designed, manufactured, structurally and geometrically functionalized, and tested in our previous research [3,4,5,6,7,8]. The concept of multi-spiked (needle-palisade) fixation of RA endoprostheses components in bone was invented by Rogala [9,10,11].…”