An Overview of the Stability and Fretting Corrosion of Microgrooved Necks in the Taper Junction of Hip Implants.

Fretting corrosion at the head-neck interface of modular hip implants, scientifically termed trunnionosis/taperosis, may cause regional inflammation, metallosis, and adverse local tissue reactions. The severity of such a deleterious process depends on various design parameters. In this review, the influence of surface topography (in some cases, called microgrooves/ridges) on the overall performance of the microgrooved head-neck junctions is investigated.

The Role of the Assembly Force in the Tribocorrosion Behaviour of Hip Implant Head-Neck Junctions: An Adaptive Finite Element Approach.

The cyclic loading, in the corrosive medium of the human body, results in tribocorrosion at the interface of the head-neck taper junction of hip implants. The resulting metal ions and wear debris adversely affect the local tissues. The force applied by surgeons to assemble the junction has proven to play a major role in the mechanics of the taper junction which, in turn, can influence the tribocorrosion damage.

The mechanics of head-neck taper junctions: What do we know from finite element analysis?

Modular hip implants are widely used in hip arthroplasty because of the advantages they can offer such as flexibility in material combinations and geometrical adjustments. The mechanical environment of the modular junction in the body is quite challenging due to the complex and varying off-axial mechanical loads of physical activities applied to a tapered interface of two contacting materials (head and neck) assembled by an impact force intraoperatively. Experimental analogies to the in-vivo condition of the taper junction are complex, expensive and time-consuming to implement; hence, computational simulations have been a preferred approach taken by researchers for studying the mechanics of these modular junctions that can help us understand their failure mechanisms and improve their design and longevity after implantation.

A review on the finite element simulation of fretting wear and corrosion in the taper junction of hip replacement implants.

Taperosis/trunnionosis is a scientific term for describing tribocorrosion (fretting corrosion) at the head-neck taper junction of hip implants where two contacting surfaces are undergone oscillatory micromotions while being exposed to the body fluid. Detached ions and emitted debris, as a result of taperosis, migrate to the surrounding tissues and can cause inflammation, infection, and aseptic loosening with an ultimate possibility of implant failure. Improving the tribocorrosion performance of the head-neck junction in the light of minimising the surface damage and debris requires a better understanding of taperosis.