Outcomes comparison between novel hydroxyapatite enhanced polyetheretherketone and titanium implants after anterior lumbar interbody fusion

Background: Interbody implants have evolved to reduce the risk of nonunion with polyetheretherketone (PEEK) and subsidence with titanium devices. Two novel anterior lumbar interbody fusion (ALIF) implants, hydroxyapatite (HA) infused PEEK (HA PEEK) and titanium alloy with microtextured HA infused surface [titanium hydroxyapatite (TiHA)] may overcome these inherent risks. The primary objective of this study was to compare subsidence and fusion rates between HA PEEK and TiHA implants. Secondarily, reoperation rates and changes in patient reported outcomes were compared. Methods: In this multicenter retrospective analysis, data was extracted for adult circumferential ALIF ≤3 levels using HA PEEK or TiHA implants. Primary outcomes included rates of subsidence at 12 months and fusion at 6 and 12 months. Secondary outcomes included reoperation rates up to 12 months and changes in ODI and VAS back pain scores at 12 months. Fusion and subsidence were evaluated using an automated, computer vision-based analysis of radiographs. Fusion was defined as