Recent advances in additive manufacturing technology now enable fused filament fabrication (FFF) of Polyetheretherketone (PEEK). A standardized lumbar fusion cage design was 3D printed with different speeds of the print head nozzle to investigate whether 3D printed PEEK cages exhibit sufficient material properties for lumbar fusion applications. It was observed that the compressive and shear strength of the 3D printed cages were 63-71% of the machined cages, whereas the torsion strength was 92%. Printing speed is an important printing parameter for 3D printed PEEK, which resulted in up to 20% porosity at the highest speed of 3000 mm/min, leading to reduced cage strength. Printing speeds below 1500 mm/min can be chosen as the optimal printing speed for this printer to reduce the printing time while maintaining strength. The crystallinity of printed PEEK did not differ significantly from as-machined PEEK cages from extruded rods, indicating that the processing provides similar microstructure.

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Additive manufacturing (AM) of high temperature polymers, specifically polyaryletherketones (PAEK), is gaining significant attention for medical implant applications. As 3D printing systems evolve toward point of care manufacturing, research on this topic continues to expand. Specific regulatory guidance is being developed for the safe management of 3D printing systems in a hospital environment. PAEK implants can benefit from many advantages of AM such as design freedom, material and antibacterial drug incorporation, and enhanced bioactivity provided by cancellous bone‐like porous designs. In addition to AM PAEK bioactivity, the biomechanical strength of 3D printed implants is crucial to their performance and thus widely studied. In this review, we discuss the printing conditions that have been investigated so far for additively manufactured PAEK implant applications. The effect of processing parameters on the biomechanical strength of implants is summarized, and the bioactivity of PAEKs, along with material and drug incorporation, is also covered in detail. Finally, the therapeutic areas in which 3D printed PAEK implants are investigated and utilized are reviewed.

Pedicle screws are the main fixation devices for certain surgeries. Pedicle screw loosening is a common problem especially for osteoporotic incidents. Cannulated screws with cement augmentation are widely used for that kind of cases. Dual lead dual cored pedicle screw has already given promising pullout values without augmentation. This study concentrates on the usage of dual lead dual core with cement augmentation as an alternative to cannulated and standard pedicle screws with cement augmentation. Five groups (dual lead dual core, normal pedicle screw and cannulated pedicle screw with augmentation, normal pedicle screw, dual lead dual cored pedicle screw) were designed for this study. Healthy bovine vertebrae and synthetic polyurethane foams (grade 20) were used as embedding test medium. Test samples were prepared in accordance with surgical guidelines and ASTM F543 standard testing protocols. Pullout tests were conducted with Instron 3300 testing frame. Load versus displacement values were recorded and maximum pullout loads were stated. The dual lead dual cored pedicle screw with poly-methyl methacrylate augmentation exhibited the highest pullout values, while dual lead dual cored pedicle screw demonstrated similar pullout strength as cannulated pedicle screw and normal pedicle screw with poly-methyl methacrylate augmentation. The dual lead dual cored pedicle screw with poly-methyl methacrylate augmentation can be used for osteoporotic and/or severe osteoporotic patients according to its promising results on animal cadaver and synthetic foams.

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This study describes a detailed analytical characterization of polyaryletherketone (PAEK) polymers used in extrusion‐based additive manufacturing. The results provide key observations and highlight differences between commercially available polymers of the PAEK family, specifically polyetheretherketone (PEEK) and polyetherketoneketone (PEKK). Results suggest that inherent differences in their molecular structure lead to notable differences in terms of their viscoelastic, thermal and physical properties. Similarly, direct comparison of the properties between parent filaments and three‐dimensional printed (3DP) parts suggests that, as observed in subtractive processes, the molecular structure of the PAEK polymer selected (PEEK or PEKK), as well as the inherent physical properties associated with it, determine greatly the performance of final 3DP parts. Differential scanning calorimetry results suggest that the glass transition temperature (Tg) of PEEK 3DP bars (146.8 °C) is about 8 °C lower than that of the parent PEEK filament (154.8 °C). These small differences manifest greatly in the viscoelastic response after Tg, and the temperature at which a decrease in storage modulus is observed occurs consistently at lower temperatures in 3DP PEEK bars (ca 130 °C) compared to PEEK filaments (ca 150 °C). In contrast, no observable differences are noted between parent filaments and 3DP bars in PEKK polymers. For these polymers, the inherent semi‐crystalline behavior dominates their thermal and viscoelastic response. These structure–property relationships provide fundamental understanding to aid in the design and manufacturing of several industrial and biomedical applications that could potentially leverage the advantages of high‐temperature thermoplastic PAEK resins, as well as in the incorporation of these polymers in a growing number of technologies encompassing the field of additive manufacturing. © 2021 Society of Industrial Chemistry.