Review of anterior cervical diskectomy/fusion (ACDF) using different polyetheretherketone (PEEK) cages

BACKGROUND: Multiple anterior cervical diskectomy/fusion (ACDF) techniques now use a variety of Polyehteretherketone (PEEK) cages; stand-alone (SA) and zero-profile (ZP) with/without screws, cages filled with demineralized bone matrix/autograft, and cages coated with hydroxyapatite or titanium. We compared the safety/ efficacy between different PEEK ACDF cage constructs in 17 studies, and in some cases, additionally contrasted results with “routine” ACDF (i.e. series/historical data performed with combinations of iliac autograft/allograft and plates). METHODS: We focused on the clinical outcomes, fusion rates, postoperative radiographic changes/lordosis/ subsidence, and/or reoperation rates for various PEEK ACDF constructs vs. “routine” ACDF. RESULTS: One to 3 and 4-level PEEK ACDF cages demonstrated high fusion rates, few cage failures, and low reoperation rates. Subsidence for PEEK ACDF cages did not reduce fusion rates or diminish the quality of postoperative outcomes. Further, titanium-coated (T-C) PEEK cages lowered fusion rates in one study (i.e. 44.1% fusions vs. 88.2% for routine PEEK ACDF) while ACDF PEEK cages coated with hydroxyapatite (HA) showed only a “trend” toward enhanced arthrodesis. CONCLUSION: One to 3-4 multilevel ACDF PEEK cage constructs demonstrated comparable safety/efficacy when compared with each other, or in select cases, with “routine” ACDF (i.e. using autograft/allograft and plates).