Two-level Anterior Cervical Discectomy and Fusion Using Self-locking Stand-alone Polyetheretherketone Cages with Two Anchoring Clips Placed in the Upper and Lower Vertebrae, Respectively

Background: Anterior cervical discectomy and fusion (ACDF) is a widely accepted surgical procedure for the treatment of cervical degenerative disk diseases (CDDD). The purpose of our study was to investigate the reliability and efficacy of ACDF using self-locking stand-alone polyetheretherketone (PEEK) cages, with two anchoring clips placed in the upper and lower vertebrae, respectively.

Methods And Materials: Twenty-six patients who underwent ACDF using a stand-alone PEEK cage packed with local osteophytes and cancellous allograft bone from January 2010 to January 2012 were enrolled in this study. Clinical findings were assessed using a visual analog scale (VAS), Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), and Odom criteria. Intervertebral height and cervical fusion status were assessed on X-ray.

Results: Twenty-six patients underwent ACDF using a stand-alone PEEK cervical cage. All patients had a minimum 2 years of follow-up. The operative levels were C3/4, C4/5 in seven patients, C4/5, C5/6 in 13 patients, and C4/5, C6/7 in six patients. At 3 days, 6 months, and 2 years of follow-ups, the JOA scores were 10.41 ± 1.67, 13.78 ± 1.91, 14.42 ± 2.09, respectively, which was significantly higher (p < 0.01) than preoperative (7.34 ± 1.71), whereas VAS overall pain score was 4.35 ± 1.32, 1.73 ± 0.44, 1.32 ± 0.57, respectively, which was significantly lower (p < 0.01) than preoperative (8.01 ± 1.16). The NDI preoperatively was 33.94 ± 11.75, 23.53 ± 10.92 at 3 days postoperatively, 12.64 ± 8.36 at 6 months, and 10.74 ± 7.92 at 2 years of follow-ups. Intervertebral height was 5.99 ± 0.31 mm preoperatively, 8.70 ± 0.23 mm at 3 days, 8.34 ± 0.61 mm at 6 months, and 8.22 ± 0.35 mm at 2 years of follow-ups. According to Odom criteria, 10 patients (38.4%) presented with an excellent clinical outcome, 15 good (57.6%), 1 fair (3.8%), and no patient presented a poor outcome. Solid fusion was achieved in all patients (100%) at a mean time of 4.5 months.

Conclusion: ACDF using a self-locking stand-alone PEEK cage with two anchoring clips placed in the upper and lower vertebrae, respectively, could be considered a safe and effective substitute for fusion in patients with two-level CDDD; it can effectively restore the intervertebral height, facilitate radiologic follow-up, cause few complications, and lead to satisfactory outcomes.