A retrospective case series.Objective.
To assess the diagnostic utility of sequential anteroposterior (AP) radiographs for following patients with postoperative anterior cervical decompression and fusion (ACDF).Summary of Background Data.
There are currently no widely accepted standards for radiographical follow-up after ACDF. Many spine surgeons routinely obtain at least AP and lateral films at serial follow-up visits. It is generally accepted that lateral films are of utility to assess overall alignment, evaluate union, and detect any potential construct-related issues. It is our perception that the AP view adds little or no clinical value after documentation of alignment on an initial film.Methods.
All follow-up imaging series were evaluated for 100 patients who underwent ACDF. Variables thought to be potentially detected on the AP film were evaluated on both the AP and lateral films (visualization of the implant and instrumented vertebral bodies and any construct-related issues). In addition, angulation of the implant relative to the vertebral axis of the instrumented levels was measured on the AP film.Results.
For the 100 patients evaluated, the follow-up period was 1.2 ± 0.5 months (mean ± SD), with 4.39 ± 1.52 imaging series obtained per patient. Instrumented vertebral bodies were fully visualized in 99.5% of AP and 86.7% of lateral films obtained at follow-up visits. The entire implant was visualized in 100% of AP films and 95.6% of lateral films. No hardware-related issues were seen (screw disengagement, pullout, breakage, etc.). No patients were found to have progression of coronal plate angulation beyond 3° at their last follow-up series relative to the first follow-up visit.Conclusion.
Using rigorous evaluation methods, we found no significant incremental utility of AP films obtained in addition to lateral films. Therefore, given the inherent cost, time, and radiation exposure associated with each additional view, we propose that AP films should not be part of routine follow-up imaging after ACDF.