A short review: hydroxyapatite coatings for metallic implants

Abstract

The number of orthopedic surgeries will continue increasing over the next decades. The most common causes of orthopedic implant failure after implantation are infections, inflammatory response, corrosion, mismatch in elastic modulus, stress shielding and excessive wear. To address the problems associated with implants, different modifications related to geometry, materials and surface have been developed. Among the different methods, coating is an effective method to improve the performance of implant materials. Hydroxyapatite is the best option to coat metallic implants and it has been used in clinical practice for more than 30 years. In this article, a comprehensive review of recent studies has been carried out to summarize the impact of hydroxyapatite on metallic implants. The antibacterial characteristics, biodegradability, biocompatibility, corrosion behavior and mechanical properties for performance evaluation are briefly summarized. Different effective coating techniques and additives have been summarized. The results are useful to produce the coating with optimized properties.