Outcomes Comparison between Novel Hydroxyapatite Enhanced PEEK and Titanium Implants after Anterior Lumbar Interbody Fusion

Introduction: Interbody implants have evolved to reduce the risk of nonunion with polyetheretherketone (PEEK) and titanium devices. Two novel ALIF implants, hydroxyapatite (HA) infused PEEK (HA PEEK) and titanium alloy with microtextured surface integrated with HA (TiHA) may mitigate this risk. This study compares fusion rates, revision surgery rates, and changes in Oswestry Disability Index (ODI) scores between HA PEEK and TiHA implants.

Methods: This is a multicenter, retrospective cohort study of prospectively collected data from 27 US centers of adult ALIFs ≤3 levels using HA PEEK or TiHA implants. Pre- and 1-year post-operative ODI scores were recorded. Fusion was analyzed by validated motion detection software and defined as < 2° of angular motion. Two sample proportion tests compared fusion and revision surgery rates, and two-way ANOVA compared changes in ODI.

Results: Analysis included 566 patients (78% HA PEEK, 22% TiHA) with mean age of 53.4 years and 1.5 levels of ALIF. There was no significant difference between fusion rates with respect to angular motion (88% HA PEEK, 95% TiHA, p=0.08) at 6 months or at 1 year (92% HA PEEK, 94% TiHA, p=0.8). There was no significant difference in revision surgery rates at 1 year (3.6% HA PEEK, 1.0% TiHA, p=0.2) or in ODI changes at 1 year (-22.7 HA PEEK, -19.7 TiHA, p=0.7). Subanalysis of ALIF-only and ALIF with posterior instrumentation also showed no significant differences in these outcomes between HA PEEK and TiHA groups.

Conclusion : HA enhanced PEEK and titanium ALIF implants achieved similarly high rates of fusion, low rates of revision surgery, and improved ODI scores beyond established MCID at 6 months and 1 year. These findings demonstrate the historical nonunion risk with PEEK is mitigated by the novel HA infused PEEK implant with titanium alloy face plate and screws for ALIF.