Titanium Alloy Edges Out PEEK for a Custom Cranial Implant

One of the hot materials for medical implants is PEEK (polyetheretherketone). There was a whole track devoted to PEEK at the Medical Design and Manufacturing Conference held in Anaheim, CA, earlier this year. Its advantages include biological properties that are comparable to natural bone, good aesthetics, natural radiolucency and imaging compatibility that allows accurate monitoring of the healing site, non-conductivity of temperatures and excellent biocompatibility.  Doctors at a major American medical center also like PEEK because of high-temperature tolerance (its glass transition is 143C). PEEK can be autoclaved in any hospital operating room sterilizer, eliminating the requirement of gas or EtO sterilization.

But the same doctors ruled out use of PEEK as a custom cranial implant because of its high cost. They were quoted a price of around $14,000 for a specific cranial implant. Part of the high cost is due to the fact that it had to be milled. It made no sense to make a mold to produce one part. The medical team instead opted for an electron beam additive manufacturing process to make the implant. Estimated cost for a custom cranial implant made of titanium alloy is in the $5,000 to $8,000 range, depending on size and complexity.

Part of the problem also appears to be the price of medical-grade PEEK. Sources estimate the price of medical-grade PEEK at close to $400 per pound for injection molding material compared to about $44 per pound for industrial-grade PEEK. The price is much higher, above $1,300 per pound, for PEEK supplied as a machinable billet. A leading medical-grade PEEK producer declined to comment on the cost issue.

See the June issue of Design News for more details.