The Ceramic Modular Head Improvement in the Design of a Total Hip Replacement

Abstract

For the first time, a design of a modular ceramic ball head of a total hip joint replacement (THR) friction pair has been developed, which has the properties of a metal in conjunction with the stem neck and the properties of a ceramics on bearing surface of the pair. This is achieved by creating a low-cost, low-toxic, durable fixed connection of the head made of alumina or zirconia ceramics and the titanium-based alloy sleeve to obtain a brazed joint that is efficient in human synovial fluid. With the help of finite element analysis, a quantitative assessment of the strength and rigidity of the proposed head design was performed and its use in modern hip arthroplasty was indicated. The approbation of the proposed design solutions for creating a THR ceramic head with a titanium-based alloy sleeve brazed was carried out.

Improving the Endoprosthesis Design and the Postoperative Therapy as a Means of Reducing Complications Risks after Total Hip Arthroplasty

“…The performed finite element analysis of the head design with no sleeve showed that the greatest stress es and strains in the ceramics were at the outlet in the head. In the presence of a sleeve the zone with maximum stresses and strains shifted to the area where the ceramics are practically the thickest, and the values of stresses and strains reduced by more than 2 times [77], on the basis of which the thicknesses of the sleeve and ceramics 1 were select ed, also considering the requirements of medical standards. To create a fixed joint be tween the ceramic element of the head and the titanium alloy sleeve, the technology of their brazing was developed, as well as the solder itself with the required biocompatibility index [78].…”

Is It Possible to Create an “Ideal Endoprosthesis” for an “Ideal Total Hip Replacement”?

“…With the participation of this work's authors, a technology for soldering these materials was developed, which provides a connection with high tensile, compressive and shear strength [71]. As a result, it became possible to develop a modular femoral head, the general view and 3D model of which are shown in Figure 4.…”

Microstructure and Defect-Based Fatigue Mechanism Evaluation of Brazed Coaxial Ti/Al2O3 Joints for Enhanced Endoprosthesis Design

“…In addition to the characterization of the brazed seam, investigations on the final cubic ceramic head with the titanium insert are required in the next steps in order to verify, for example, the damping properties of the titanium insert, as already shown by simulation [27]. For this purpose, digital image correlation (DIC) or local strain measurements with strain gauges should be used, as already shown in combination for brazed steel joints in [28].…”