Anterior cervical discectomy and titanium cage fusion - 7-year follow-up.

Background and study aims: The purpose of this study was to prospectively evaluate long-term results after anterior cervical discectomy and titanium cage fusion (ACDF) and titanium cage fusion. Special focus was on the adjacent levels.

Methods: 54 patients (age: 48+/-10 years; one level operation in 44 patients and two level operation in 10 patients) entered the study. Re-evaluation consisted of a clinical out patient investigation and was possible in 33 patients. VAS, PROLO and Oswestry scores were used. Lateral radiographs were taken and changes in the operated and adjacent segments were measured and compared to radiographs directly after surgery. Clinical patient data was compared with the data prior to surgery.

Results: The mean follow-up time of the 33 patients was 7.26 +/- 0.22 years. One patient needed re-surgery of the cervical spine above the fused segment. PROLO results showed a significant improvement (PROLO F 1.52+/-0.67 to 3.79+/-1.17 p<0.01; PROLO E 1.52+/-0.5 to 3.55+/-1.42 p<0.01). Mean VAS at the time of investigation was 3.2+/-2.5. Oswestry score was 16.4+/-9.5. The alignment of the whole cervical spine was stable lordotic (Katsuura 10.9+/-9.0 degrees to 11.5+/-7.8 degrees ; p=0.76). Total segmental height had reduced from 36.6+/-4.6 mm to 34.6+/-3.9 mm (p=0.04). No significant reduction of disc space height of adjacent levels was detectable (superior: 5.8+/-1.6 mm to 5.2+/-1.6 mm; inferior: 6.0+/-1.7 mm to 5.3+/-1.9 mm). One adjacent superior level showed spontaneous fusion. Ventral and dorsal osteophytes in the superior and inferior adjacent levels increased in number and increased significantly in degree. Patients with bi-segmental fusion (n=7) showed similar results.

Conclusion: ACDF with titanium cages has good clinical long-term results. A significant progression of degenerative changes can be observed on radiographs without clinical consequences for the patients. A comparison with patients without surgery and conservative therapy is needed to allow a better interpretation of the radiological results.