Cage only or cage with plate fixation in anterior cervical discectomy and fusion surgery - analysis of a national multicenter dataset.

Background context: Anterior Cervical Discectomy and Fusion (ACDF) is a surgical technique that can be used to treat several conditions of the cervical spine. Small sized studies have reported differences in radiological findings between cage only and cage with plate fusion techniques but no differences in clinical outcome, hence, larger studies are needed.

Purpose: The aim of this study was to compare the outcomes of ACDF between cage only and cage with plate fixation.

Study design: Retrospective study design on prospectively collected registry data.

Patient sample: Individuals treated for cervical degenerative radiculopathy, with ACDF using either cage only or cage with plate fixation were identified in the Swedish Spine registry (Swespine). Included individuals had available baseline and 1-year postoperative data for the Numeric Rating Scale (NRS) for neck and arm pain.

Outcome measures: Patient reported outcome measures (PROMs) included were NRS for neck and arm pain, Neck Disability Index (NDI), and EuroQol-Visual Analogue Scale (EQ-VAS). Complications reported by clinicians and patients were also available in the Swespine registry, as well as the degree of satisfaction at the 1-year follow-up.

Methods: Outcomes at the 1-year follow-up were compared between the cage only or cage with plate groups. In a secondary analysis, one or two levels of surgery was compared between the groups. The number of patients that reached the Minimum Clinically Important Difference (MCID) in improvement after treatment was calculated and compared between the groups. The Mann Whitney-U test was used for continuous variables and the Chi² test for categorical variables.

Results: The groups included 344 individuals instrumented with cage only, and 334 receiving cage with plate fixation. NDI improvement was -14.0 points (95% CI: -12.2-[-15.8]) in the cage only group and -17.9 points (95% CI: -16.1 - [-19.8]) points in the cage with plate group (p=.007). A lower rate of hoarseness post-operatively was reported by the cage only group (OR: 0.65 [0.45-0.93], p=.026). No differences were seen in other outcomes.

Conclusion: Clinical improvement was seen in both groups, but the improvement of NDI was better in the cage with plate group and the rate of hoarseness was lower in the cage only group.