Cervical stand-alone PEEK cage versus anchored cage with screws in single-level anterior cervical discectomy and fusion: A prospective cohort study

Background: Anterior cervical discectomy and fusion (ACDF) is a gold standard procedure for surgical management of symptomatic cervical degenerative disc disease. Traditionally, iliac crest bone graft was used as a strut graft to fill the disc space after discectomy. However, several complications have been observed, including donor site hematoma, infection, and pain. A cage can be used as an alternative, but cage dislodgement can be a devastating complication. Some surgeons advocate plate application to augment the cage construct, but the incidence of dysphagia is much higher with longer operative times. An anchored cage with screws could reduce postoperative dysphagia and simultaneously fix the cage. This study compared the clinical and radiographic outcomes of stand-alone polyetheretherketone (PEEK) cage with the anchored cage with screws for single-level ACDF. Methods: This prospective study was conducted in 50 patients who underwent single-level ACDF for cervical degeneration, with radiculopathy or myelopathy, from January, 2012, to January, 2014, at a single institution. Follow-up was 2 yr. Twenty-one patients were allocated to the stand-alone cage group (group 1) and 29 to the anchored cage with screws group (group 2). The Neck Disability Index (NDI), Visual Analogue Scale (VAS) of the arm and neck, radiographic segmental cervical angle (CA), and disc height assessments were done preoperatively, at 6 mo, and at 2 yr postoperatively. Results: Clinical outcomes showed improvement in both groups. The change between final follow-up (24 mo) and 6 mo postoperative CA (P=0.01) and disc height (P=0.02) showed statistically better outcomes for the anchored cage group (group 2) than the stand-alone cage group (group 1). The VAS showed significant pain improvement in the stand-alone group (group 1) than in the anchored cage with screws group (group 2) at 2 yr. The NDI difference was highly significant (P=0.001) preoperatively and at 6 mo postoperatively in favor of group 2, but this did not persist at 2-year follow-up. Conclusions: For one-level ACDF, the anchored cage with screws has some advantage compared to the stand-alone PEEK cage in avoiding dysphagia and restoring disc space height and cervical lordosis. We suggest the anchored spacer may be a good substitute for the stand-alone cage in one-level ACDF.