Growing Orthopedic Application Means PEEK Is Far From Peaking
Memphis, Tenn. (September 19, 2018) – By John Wells, Vice President, In2Bones USA
There’s an interesting fact about polyether ether ketone (PEEK): The material, finding its way into a growing number of extremity orthopedic implants, was utilized initially in high demand industrial, automotive, electrical and aerospace applications.
Those uses required strength, durability, flexibility and safety, and they are the primary reasons why implantable devices made of the material are finding growing favor among device manufacturers and orthopedic surgeons.
From its original medical usage in spine and dental applications, PEEK’s clinical efficacy has led device makers to extend its orthopedic applications into soft tissue anchors, fracture compression plates, toe implants, and as part of bearing surfaces for joint replacement.
With approximately nine million devices implanted worldwide, over 15 years of proven clinical history and an established record of accomplishment as a safe, long-term implantable polymer, there are a multitude of reasons why PEEK is becoming an orthopedic must-have by innovative companies — with multiple benefits to the patient and surgeon.
Developed and first commercially released in the early 1980’s, PEEK found favor for its strength and durability because it could perform in high demand applications without loss of physical properties. Compared to other thermoplastics, PEEK also delivers greater strength and rigidity with excellent mechanical properties, including impact resistance, low wear rate and a low coefficient of friction.
It’s these characteristics along with PEEK’s superior biocompatibility that make it attractive as a biomaterial for medical devices where stiffness of a material, or elastic modulus, is important in orthopedic implants.
A variety of biocompatible materials reliably repair fractures, replace missing joints or bones, or support a damaged bone, among them: stainless steel, cobalt-chromium, titanium and tantalum, used alone or in combination. How and where these metals are used depends widely on the type of surgical procedure, from simple fractures to joint replacements.
While metal implants to repair fractures and reconstruct bones are commonplace, PEEK shines in applications where material strength and fatigue resistance are paramount.
PEEK pairs well with bone. Because of its ideal modulus of elasticity, PEEK’s mechanical properties approximate the high physical demands of bone, such as high fatigue strength. The polymer acts like a load-sharing device, compared to a load-bearing device, which is advantageous in dynamic areas of the body, such as the hands and feet.
These performance characteristics make PEEK-fabricated implants popular in a variety of orthopedic extremity procedures such as hammer toe reconstruction, bone fracture reduction, osteotomy fixation and arthrodesis procedures in the upper and lower extremity.
Among various extremity device manufacturers, there are hammertoe implants and soft tissue anchor products that incorporate PEEK. Recent innovation by a leading PEEK implant provider has led to several unique applications — evident in the development of a PEEK compression staple for Akin and Austin procedures and a distal radius plate for wrist fractures. These recent innovations, and the many existing PEEK products, underscore its numerous advantages for both patients and surgeons.
Advantages for Patients
Patients want to solve their medical issues and live active lives normally after surgery. PEEK not only performs well clinically, it helps to protect a patient’s health through its inert, bio-friendly features.
PEEK is stable, durable and non-toxic to the human body, and is highly resistant to biodegradation and attack by both organic and aqueous environments. So, it allows for long-term implantation. Once implanted, PEEK is impervious to organic processes. PEEK does not corrode nor does it liberate metal ions.
While the long-term presence of metals in vivo can trigger allergic tissue reactions, PEEK does not produce reactions often associated with titanium or stainless steal orthopedic implants, even after prolonged exposure. There are no nickel or metal sensitivity concerns with PEEK.
Even if additional treatment is necessary, PEEK implants may be easier to remove than metal implants. For example, in hammertoe treatment, PEEK implants allow for solid internal fixation but can be removed if there is reason to alter the fixation, which can be difficult with stainless steel or titanium products.
Advantages for Surgeons
PEEK implants also provide advantages for orthopedic surgeons who must have considerable confidence in the implants they choose. The mechanical properties of the material allow devices made with PEEK to meet the high mechanical demands of the patient and provide a level of assurance the material will withstand the physical demands of the bone.
Various PEEK implants, such as staples, are now available pre-sterilized, with accompanying inserter to make application easier. PEEK implants also makes for easier imaging. The material is radio transparent, which greatly improves radiographic assessment and allows unobscured intra-operative viewing and enhanced post-operative monitoring. The ability to view tissue and bone growth enhances the ease of evaluation of osteosynthesis fusion during the healing process
As PEEK’s use grows, the stage is being set for its application in larger, more complex medical uses. Because the material can be fabricated almost without limit, PEEK’s physical characteristics make it possible to create an implant of virtually any shape and design.
Manufacturers continue to push the envelope in PEEK design and innovation. For example, a PEEK total knee replacement implant has undergone pre-clinical trials, clearing a pathway for human trials to demonstrate PEEK’s ability to act as an articulation surface in joint replacement surgery.
While current clinical experience is confirming that PEEK based implants have significant patient benefits in extremity surgery, there are still immense possibilities for innovative development as orthopedic surgeons and device manufactures look to PEEK for technology that will reduce surgical risks, increase implant longevity and improve patient outcomes and quality of life.
By the looks of it, PEEK has yet to hit its stride.
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John Wells is Area Vice President at In2Bones USA with 20+ years of experience in the orthopedic device field encompassing all roles such as hospital servicing, product distribution, sales management and contracting. Reach John at firstname.lastname@example.org.