Invibio launched PEEK-OPTIMA™ in 1999 as the world's first implantable PEEK polymer. The implant material is ideal for spinal surgery because PEEK is radiolucent and has a modulus of elasticity close to bone, reducing stress shielding.
However, PEEK is not osteoconductive; the material supports only limited bony ongrowth or osteointegration. As a result, Invibio fully integrated hydroxyapatite (HA), a well-known osteoconductive material, into the PEEK-OPTIMA Natural matrix, to enhance bone apposition. PEEK-OPTIMA™ HA Enhanced makes Hydroxyapatite available on all surfaces of a finished device to promote spinal fusion.
PEEK-OPTIMA™ HA Enhanced received the first FDA 510(k) clearance for a cervical interbody fusion Device in 2014 and the first human implantation occurred the next year. Since then devices for cervical standalone and lumbar fusion (TLIF, PLIF) have received clearance with more than 2600 human implantations having been performed overall. Surgeons have reported observing very rapid visible bone fusion in the interbody region in six weeks on plain radiographs, with correspondingly good clinical result.
In a webinar titled, "PEEK-OPTIMA™ HA Enhanced Devices for Cervical and Lumbar Fusion: Insights from Early Clinical Experience", Invibio's Global Strategic Marketing Manager Michael Veldman discussed the technology while surgeons Timothy D. Bassett, MD, of Tuscaloosa, Al-based Southeastern Spine Specialists, and Brad G. Prybis, MD, of Carrollton (GA) Orthopaedic Clinic, presented case studies using PEEK-OPTIMA HA Enhanced devices.
"It's important to look at the history and literature to understand what has been tried before and better understand what may work in the future," said Mr. Veldman. He outlined three studies examining PEEK-OPTIMA and titanium to demonstrate the strong clinical history of PEEK-OPTIMA in spine procedures.
One study published in the September 2016 edition of BMC Musculoskeletal Disorders, titled "Is PEEK cage better than titanium cage in anterior cervical discectomy and fusion surgery? A meta-analysis," compared PEEK cages to titanium cages for patients undergoing anterior cervical discectomy and fusion. The meta-analysis included data from two randomized and two non-randomized clinical trials evaluating 184 segments from 107 patients who underwent surgery with a PEEK cage and 211 segments from 128 patients who underwent surgery with a titanium cage.
The study authors found both cages produced similar results for:
• Functional status from the Odom criteria
• Fusion rates
• Final local segmental angle
• Loss of correction
The study authors found more subsidence in the titanium cage group and concluded the functional and radiographic performance between patients who underwent ACDF with PEEK and titanium cages were similar.
A separate study published the year before in BMC Musculoskeletal disorders titled "The design evolution of interbody cages in anterior cervical discectomy and fusion: a systematic review," included an analysis of cage materials comparing PEEK, titanium and carbon fiber reinforced polymers. The researchers found:
• The fusion rate for patients who received titanium cages was 86.5 percent to 99 percent at 12 months after surgery while patients who received PEEK cages reported a 93 percent to 100 percent fusion rate one year after surgery.
• The subsidence rate was 0 percent to 14.2 percent among patients who received PEEK cages and 9 percent to 45 percent among patients who received titanium cages.
• Eighty percent to 96 percent of the PEEK cage patients reported good-to-excellent clinical outcomes, compared to 46 percent to 95 percent of the patients with titanium cages.
The final study he discussed, published in the May 2012 edition of Spine, compared how host bone responded to PEEK and porous tantalum implants for cervical spinal fusion in a goat model. The study authors found the porous tantalum implants were better at supporting the bone growth into and around the implant, but Mr. Veldman noted these results didn't translate to the clinical use in humans and recommended surgeons consider the level of evidence in studies when evaluating new technologies.
Dr. Prybis shared case studies from a series of eight patients who underwent two- or three-level ACDF, with cervical cages made with PEEK-OPTIMA™ HA Enhanced. All patients reported their arm pain was resolved and five reported their neck pain was resolved; two additional patients reported improved neck pain. All patients reported improved neurological function while three had residual numbness and one reported residual weakness. All patients reported complete fusion at all levels, 6 months post-operatively
Dr. Prybis also shared two cases with PEEK-OPTIMA™ Natural and demonstrated how PEEK-OPTIMA™ HA Enhanced improved outcomes.
"In conclusion, the PEEK-OPTIMA™ HA Enhanced device provided as good or better clinical results when compared to traditional PEEK interbody fusion devices. With consistently good outcomes at early timepoints, I am looking forward to the results of further clinical studies." Dr. Prybis said.
Dr. Bassett then shared his series of nine patients who underwent one- or two-level lumbar fusions using the TLIF (Transforaminal Lumbar Interbody Fusion) procedure with lumbar cages made from PEEK-OPTIMA HA Enhanced plus autograft bone with posterior instrumentation. No biologics were used. His patients reported no neurological incidence six weeks after surgery. None of the patients had implant migrations, subsidence or pseudarthrosis. All but one of the patients reported solid fusions at six months after surgery. However, this patient was progressing to fusion and used one pack of tobacco daily, both pre- and post-operative, contributing to the fusion challenge. At 12 months this patient demonstrated solid fusion.
"There was very rapid visible bone fusion in the interbody region in six weeks on plain radiographs and correspondingly good results," said Dr. Bassett. "You typically see the clinical result correspond with rapid growth." Dr. Bassett also reported that some of his patients demonstrated dense bone growth at the implant surface on six month CT scans which may be attributed to the hydroxyapatite.
INVIBIO™, PEEK-OPTIMA™, and INVIBIO BIOMATERIAL SOLUTIONS™ are trademarks of Victrex plc or its group companies.
Watch the webinar here.