title: PEEK-Halo effect in interbody fusion.
abstract: Recent developments have seen poly[aryl-ether-ether-ketone] (PEEK) being increasingly used in vertebral body fusion. More novel approaches to improve PEEK have included the introduction of titanium-PEEK (Ti-PEEK) composites and coatings. This paper aims to describe a potential complication of PEEK based implants relating to poorer integration with the surrounding bone, producing a "PEEK-Halo" effect which is not seen in Ti-PEEK composite implants. We present images from two patients undergoing anterior lumbar interbody fusion (ALIF). The first patient underwent an L5/S1 ALIF using a PEEK implant whilst the second patient underwent L4/L5 ALIF using a Ti-PEEK composite implant. Evidence of osseointegration was sought using CT imaging and confirmed using histological preparations of a sheep tibia model. The PEEK-Halo effect is demonstrated by a halo effect between the PEEK implant and the bone graft on CT imaging. This phenomenon is secondary to poor osseointegration of PEEK implants. The PEEK-Halo effect was not demonstrated in the second patient who received a Ti-PEEK composite graft. Histological analysis of graft/bone interface surfaces in PEEK versus Ti-PEEK implants in a sheep model further confirmed poorer osseointegration of the PEEK implant. In conclusion, the PEEK-Halo effect is seen secondary to minimal osseointegration of PEEK at the adjacent vertebral endplate following a PEEK implant insertion. This effect is not seen with Ti-PEEK implants, and may support the role of titanium in improving the bone-implant interface of PEEK substrates.
authors.affiliation: Neuro Spine Clinic, Suite 7a, Level 7 Prince of Wales Private Hospital, Barker Street, Randwick, NSW 2031, Australia; NeuroSpine Surgery Research Group (NSURG), Sydney, NSW, Australia.
authors.forename: Kevin
authors.initials: K
authors.lastname: Phan
authors.affiliation: NeuroSpine Surgery Research Group (NSURG), Sydney, NSW, Australia.
authors.forename: Jarred A
authors.initials: JA
authors.lastname: Hogan
authors.affiliation: NeuroSpine Surgery Research Group (NSURG), Sydney, NSW, Australia.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Assem
authors.affiliation: Neuro Spine Clinic, Suite 7a, Level 7 Prince of Wales Private Hospital, Barker Street, Randwick, NSW 2031, Australia; NeuroSpine Surgery Research Group (NSURG), Sydney, NSW, Australia. Electronic address: ralphmobbs@hotmail.com.
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Mobbs
mesh_terms: D000818:Animals; D001577:Benzophenones; D005260:Female; D006801:Humans; D007659:Ketones / Q000627:therapeutic use*; D008297:Male; D016348:Osseointegration; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011108:Polymers; D019736:Prostheses and Implants / Q000009:adverse effects*; D012756:Sheep; D013123:Spinal Fusion / Q000379:methods*; D014025:Titanium / Q000627:therapeutic use*
chemical_list: D001577:Benzophenones; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols; D014025:Titanium
keywords: Anterior lumbar interbody fusion; Bone–implant interface; Osseointegration; PEEK; Titanium; Titanium coating