Polyetheretherketone (PEEK) possesses a set of characteristics superior for biomedical applications including excellent mechanical properties, suitable biocompatibility and chemical resistance. More importantly, the elastic modulus of PEEK is analogous to that of human cortical bone. Thus, PEEK material is considered as a prime candidate to replace conventional biomedical metallic materials as hard tissue repair and substitute implants. However, PEEK material is naturally bioinert, and to some extent, poor osteointegration between PEEK implant and surrounding bone tissue hinders its biomedical applications in hard tissue repair and substitute field. Currently, researchers mainly add bioactive ceramics such as calcium phosphate (CaP), bioactive glass (BGs) and calcium silicate (CS) to PEEK matrix to prepare composite for enhancing bioactivity and osteointegration strength between PEEK implant and bone tissue. Unfortunately, the addition of these bioactive ceramics to PEEK have resulted in trade-offs between mechanical properties and bioactivity. How to enhance PEEK bioactivity and retain its mechanical properties at the same time has become a hot area of current research. This paper reviews the research progress and status in the aspects of preparation, mechanical properties and biological performance of these materials for hard tissue implant, and predicts its future development.

Contents
1 Introduction
2 PEEK/calcium phosphate composites
2.1 PEEK/hydroxyapatite composite
2.2 PEEK/β-tricalciumphosphate composite
3 Other PEEK composites
3.1 PEEK/carbon nanotubes/bioactive glass composite
3.2 PEEK/calcium silicate composite
3.3 PEEK/nano-titanium oxide composite
4 Conclusion