LM PAEK Can Outperforms PEEK In Certain Applications

Why It Matters

The findings validate polymer‑based, patient‑specific knee implants as a viable, metal‑free alternative, potentially reducing corrosion, hypersensitivity, and imaging artefacts while matching bone‑level loads.

Key Takeaways

• LM PAEK reached 16 kN shear strength, surpassing PEEK
• Diamond TPMS at 50% porosity gave optimal performance
• Lower nozzle temperatures favored LM PAEK, higher for PEEK
• Printed porosity fell short of design, especially LM PAEK
• Study used cylindrical surrogates, not full cone geometries

Pulse Analysis

Metal cones dominate knee revision surgery, but they introduce corrosion, nickel‑cobalt‑chromium exposure, and imaging artefacts. Polyaryletherketones such as PEEK and its low‑melt variant offer radiolucency, bone‑like modulus, and biocompatibility, yet their adoption has been limited by manufacturing challenges. Recent advances in high‑temperature fused filament fabrication now enable the creation of lattice‑rich, patient‑specific structures that mimic trabecular bone while maintaining mechanical integrity.

The Drexel team’s systematic Taguchi experiment revealed that LM PAEK not only tolerates higher porosity but also delivers superior shear strength—up to 16 kN—when printed with a 0.3 mm layer height, lower nozzle and chamber temperatures, and a diamond TPMS at 50 % porosity. In contrast, PEEK required higher extrusion temperatures and finer layers to reach its peak performance. Micro‑CT analysis showed consistent porosity undershoot, especially for LM PAEK, highlighting the need for tighter process control. These data suggest that material chemistry dictates distinct optimal printing windows, and that diamond lattices are more forgiving than gyroid designs under the thermal constraints of polymer extrusion.

For orthopedic device manufacturers, the study signals a credible pathway to replace metal cones with polymer alternatives, eliminating metal ion release and simplifying postoperative imaging. However, translation to clinical use will hinge on further validation: fatigue testing, in‑vivo osseointegration, sterilization resilience, and regulatory clearance of specific LM PAEK grades. Scaling from cylindrical test coupons to patient‑specific cones will demand robust thermal management and quality‑assurance protocols. If these hurdles are cleared, polymer‑based, high‑porosity implants could capture niche markets where metal hypersensitivity or infection risk is paramount, accelerating the shift toward fully digital, personalized orthopaedic solutions.