Additively manufactured polyether ether ketone (PEEK) skull implant as an alternative to titanium mesh in cranioplasty.

173Cranioplasty is used for skull defects, involving lifting the scalp and restoring the contour of the skull with the original skull piece, titanium mesh, or solid biomaterial. Additive manufacturing (AM) technology, known as three-dimensional (3D) printing, is now utilized by medical professionals to develop customized replicas of tissues, organs and bones, offering a valid option with perfect anatomic fitting in the individual and skeletal reconstruction. Here, we report a case that underwent titanium mesh cranioplasty 15 years ago. The poor appearance of the titanium mesh weakened the left eyebrow arch and resulted in the formation of a sinus tract. Cranioplasty was performed using an additively manufactured polyether ether ketone (PEEK) skull implant. PEEK skull implants have been successfully implanted without any complications. To our knowledge, this is the first reported case of direct use of fused filament fabrication (FFF)-fabricated PEEK implant for cranial repair. The FFF-printed PEEK customized skull implant could possess simultaneously with adjustable material thickness and more complex structure, tunable mechanical properties, and low processing costs compared with traditional manufacturing processes. While meeting clinical needs, this production method is an appropriate alternative for promoting the use of PEEK materials in cranioplasty.

Additive manufactured polyether-ether-ketone implants for orthopaedic applications: a narrative review.

Polyether-ether-ketone (PEEK) is believed to be the next-generation biomedical material for orthopaedic implants that may replace metal materials because of its good biocompatibility, appropriate mechanical properties and radiolucency. Currently, some PEEK implants have been used successfully for many years. However, there is no customised PEEK orthopaedic implant made by additive manufacturing licensed for the market, although clinical trials have been increasingly reported. In this review article, design criteria, including geometric matching, functional restoration, strength safety, early fixation, long-term stability and manufacturing capability, are summarised, focusing on the clinical requirements. An integrated framework of design and manufacturing processes to create customised PEEK implants is presented, and several typical clinical applications such as cranioplasty patches, rib prostheses, mandibular prostheses, scapula prostheses and femoral prostheses are described. The main technical challenge faced by PEEK orthopaedic implants lies in the poor bonding with bone and soft tissue due to its biological inertness, which may be solved by adding bioactive fillers and manufacturing porous architecture. The lack of technical standards is also one of the major factors preventing additive-manufactured customised PEEK orthopaedic implants from clinical translation, and it is good to see that the abundance of standards in the field of additive-manufactured medical devices is helping them enter the clinical market.