gms | German Medical Science

Objective: Nonunion is considered to be the major complication after spine surgery. Dorsal fixation of the cervical spine is often combined with posterolateral bone chip attachment or median bone graft cerclage. Fusion rates with these techniques have been described in up to 98%, although over 90% of bone graft resorption has been seen with allograft. In these cases a delayed fusion could still be detected. Aim of the present study was to investigate if dorsal fixation alone in comparison to fixation plus additional use of fusion material provides a sufficient fusion and stability.

Methods: We retrospectively analyzed our local database for patients with dorsal instrumented cervical spine. 72 patients (34 = f; 38 = m) out of 206 between 2013 and 2017 met the criteria for degenerative cervical spinal stenosis or trauma with available follow up data (FU). X-rays or CT-scans were performed for radiographic confirmation of lytic halo signs, screw displacement or bone fusion.

Results: 39 (54.2%) patients (mean age 69.7 yrs.) had a dorsal screw-rod fixation (FIX) without and 33 (45.8%; mean age 68.1 yrs.) with additional fusion technique (FIFU). Mean FU was 6.5 mo. in the FIX group and 10.3 mo. in the FIFU group. Lytic halo signs around the screws could be detected in 7 (18%) cases in the FIX group and 5 (15.2%) cases in the FIFU group which was not significantly different (p = 0.79). However, lytic halo signs after dorsal instrumentation occurred more frequently in degenerative than in traumatic diseases (p = 0.03). Only one case in each group needed surgical revision because of instability. Radiographic fusion signs appeared in 8 (20.5%) cases in the FIX group and in 3 (9.1%) cases in the FIFU group.

Conclusion: Dorsal screw-rod fixation without additional material seems not to be inferior to additional fusion technique in the treatment of degenerative and traumatic cervical spinal diseases.