Overview of Orthopedic Implant Materials and Associated Problems

Orthopedic Implant is a high-risk medical device. Its main function is stabilization and fixation of bone but some are functional devices like hip arthroscopy, knee joint replacement implants, spinal cages, etc. Some common materials used to manufacture implants are Titanium, Titanium alloy (Ti6Al4V) as per ISO 5832-3, Stainless Steel-316 as per ISO 5832-1, tantalum, bioabsorbable material like PLLA, PGA, PLDLA, etc. The implant should have some fundamental properties such as being biocompatible, corrosion resistant, and having good mechanical properties. Though the implants have these properties, some complications like bacterial adhesion cause infection, poor osseointegration, and loosening of the implant. To overcome these complications, one of the effective and simple solutions is coating. The coating can enhance osseointegration, reduce infection, increase bone ingrowth and mechanical strength, etc. The coating of a material with desirable properties over the implant is a tough and complex process. The antibacterial coating materials are chitosan, gentamicin, Rifampicin, Titanium oxide, etc. Similarly, the coating material for osseointegration is hydroxyapatite (HA), extracellular matrix (ECM), magnesium coating, etc. There are different technique for coating materials like the Dip-Coating method, magnetron sputtering, sol-gel technique, electrophoretic deposition, etc. Although coating is the most effective way to overcome some above-mentioned complications, most of the implants are sold on the market without coating. Coating is a complicated and costly process. It is still in its niche in research and development, however, it has a lot of potential for the future. Hence, in this chapter, the author mainly focuses on orthopedics implant materials, associated problems, and distinct coating materials techniques, which are discussed in detail.

Keywords: Coatings, Corrosion, Implants, Infection, Issues, Material, Osseointegration, Scope, Wear.