It is known that one of the most progressive and most used in world medical practice friction couples in total hip arthroplasty (THA) is a couple including ceramic elements. This is due to the fact that currently, due to the influence of negative factors of a deteriorating environment, the age rejuvenation is noted for patients who already need a total hip replacement (THR) in terms of indicators and for which it should has the longest service life. The popularity of ceramics is due to the fact that it has the highest wear resistance, it and its wear products are bio inert and practically do not cause osteolysis due to the response of the immune system to these ones.

But ceramics has a very important drawback: it is fragile and with significant dynamic loads, for example, when jumping from a height, it can be destroyed in mating with the tapered neck of the THR stem. To prevent this factor, a number of known designs have been proposed in which a ceramic head mates with the neck of a stem by means of a plastic or metal sleeve that is not fixed motionlessly to the head. This creates a movable joint in the indicated site during THR operation due to the effect of cyclic loads. The presence of a soft plastic sleeve aggravates the process, leading to loosening of the unstable connection between the head and neck, instability in the elements of the THR, impaired joint biomechanics and manifestation of pain syndromes, and, consequently, the need for revision arthroplasty.

The main goal of the work is to develop the design of a THR with a modular ceramic head having metal properties in mating with the tapered neck and ceramic properties on the bearing surface of a friction couple by creating a low-cost, low-toxic, durable joint of alumina or zirconium ceramic and titanium alloy to obtain a soldered connection, operable in human synovial fluid. Using finite element analysis, a qualitative and quantitative assessment of the strength and stiffness of the proposed head design was performed.

Using a head of this design will allow not only to realize the main advantages of a ceramic-ceramic friction couple in THR, but also ensure that there are no breaking loads for ceramics at the tapered place of the head and stem, as well as undesirable physicochemical processes in this conjunction, for example, fretting-corrosion which is also known to be present and in existing commercial ceramic THR. The indicated advantage is due to the presence of homogeneous biocompatible metal materials (Ti-based alloy) in their connection.