Comparison between Acrylic Cage and Polyetheretherketone (PEEK) Cage in Single-Level Anterior Cervical Discectomy and Fusion: A Randomized Clinical Trial.

STUDY DESIGN:: Prospective, single-blind randomized controlled clinical study.

OBJECTIVE:: To compare polyetheretherketone (PEEK) cage with a novel Acrylic cage to find out which fusion cage yielded better clinical outcomes following single-level anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA:: ACDF is considered a standard neurosurgical treatment for degenerative diseases of cervical intervertebral discs. There are many options, including bone grafts, bone cement, and spacers made of titanium, carbon fiber, and synthetic materials, used to restore physiologic disc height and enhance spinal fusion, but the ideal device, which would provide immediate structural support and subsequent osteo-integration and stability, has not been identified yet. To overcome this, we designed a new, inexpensive Acrylic cage.

METHODS:: A total of 64 patients were eligible to participate and were randomly allocated to undergo ACDF either with Acrylic interbody fusion cage filled with bone substitute (n=32) or PEEK cage (n=32). Nurick's grading was used for quantifying the neurological deficit. Clinical and radiological outcome was assessed preoperatively, immediately after surgery, and subsequently at 2, 6, and 12 months follow up using Odom's criteria and dynamic radiographs (flexion-extension) and CT scans, respectively.

RESULTS:: There was a statistically significant improvement in the clinical outcomes of the Acrylic cage group compared with the PEEK cage group (mean difference: -0.438, 95% CI -0.807 to -0.068; P=0.016). There was a statistically significant difference in DSH increase between the two groups at the 6- and 12-month follow-up. The Acrylic cage achieved higher fusion rate (good fusion) than the PEEK cage (96.9% vs. 93.8%). Intervertebral angle (IVA) demonstrated a significant difference among the two treated groups throughout the follow-up period.

CONCLUSIONS:: This study suggests that the use of Acrylic cage is associated with good clinical and radiological outcomes and it can be therefore a good substitute for bone graft and other cages in ACDF.