Outcome of cervical spinal levels adjacent to anterior fusion: l ong-term follow-up

Abstract

Purpose of study: The consequences of anterior cervical fusion on the adjacent vertebral levels are of increasing concern among spinal surgeons. In a previous study we followed 300 patients for 40 months after anterior cervical fusion. Results clearly showed high frequency of degeneration (osteophytes and/or instability), primarily at the level cephalad to fusion ranging from 21% in young trauma cases to 57% in postdegenerative cases. The goal of this study was to follow this cohort for 5 more years.Methods used: Attempts were made to reexamine the 300 patients studied in 1996 using dynamic X-rays, clinical assessment and cervical pain analysis on a visual analog pain scale (VAPS). The follow-up procedure was completely performed in 136 and partially performed in 34. Twenty-two agreed only to answer by phone. Eight had died, and the rest were lost to follow-up. Clinical results in these three groups were similar for the items available.of findings: Patients were separated in three groups according to disorders before surgery. Mean follow-up was 102.5 months (84 to 180 months). Among 42 patients reviewed, deterioration of the overlying level increased from 21% in 1996 to 69% in 2001. Deterioration of the underlying level increased from 26% to 47.6%. Cervical pain remained mild (20 of 100 in 1996, 27 of 100 in 2001). Degenerative cases (nerve-root compromise requiring discectomy alone or with osteosynthesis, or one-level corpectomy). Among 42 patients reviewed, results were similar in the three groups. Deterioration of the overlying level increased from 57% to 89%. Deterioration of the underlying level increased from 22% to 41%. Cervical pain increased from 14 of 100 in 1996 to 41 of 100 in 2001.Relationship between findings and existing knowledge: Among 52 patients reviewed, deterioration of the overlying level increased from 54% to 81% in cases with one- or two-level corpectomies and from 40% to 70% in cases with more than two corpectomies. Deterioration of the underlying level increased from 26% to 50% in the first group and remained stable in the second. Cervical pain remained mild (18 of 100 in 1996, 23 of 100 in 2001).Overall significance of findings: These results confirm that cervical fusion increases the deterioration of adjacent levels. In the extended follow-up, the gap closed between results of the trauma group and those of the other cases. Use of mobile device will help us to differentiate between spontaneous degeneration and that induced by fusion.Disclosures: No disclosures.Conflict of interest: No conflicts.