(I-542) Clinical and Radiographic Outcomes for Patients with Cervical Adjacent Segment Disease Treated with Anterior Cervical Discectomy and Fusion with Integrated Interbody Spacers
Medical Student Duke University Durham, North Carolina, United States
Introduction: Adjacent segment disease (ASD), characterized by degenerative disease at an adjacent spinal level to a prior fusion, is a well-recognized and significant complication following anterior cervical discectomy and fusion (ACDF). This study aimed to assess the incidence of dysphagia and other complications as well as radiographic outcomes in adult patients who have undergone ACDF with integrated interbody spacer device (IS) instead of a tradition plate-cage system for symptomatic ASD.
Methods: This was a retrospective review of patients who underwent ACDF for symptomatic ASD with commercially available integrated interbody spacers by two fellowship-trained spine surgeons at an academic institution from March 2018 to April 2022. Demographic, radiographic, and postoperative data was collected, including dysphagia, device-related complications, and need for revision surgery.
Results: There were 26 patients (13 male, 13 female) that met inclusion criteria (mean age 58.1 years, mean BMI 30.5 kg/m2) that had undergone ACDF for symptomatic ASD (one-level, n=23 (88.5%); two-level, n=3 (11.5%)). Of 22 patients with prior plate-cage systems in place, none required hardware removal at the time of surgery. Overall, nine (34.6%) patients experienced dysphagia postoperatively. One patient had severe dysphagia, necessitating otolaryngology referral and swallow study. Two (7.7%) patients experienced postoperative complications, which were gait instability and vocal cord granulomas. Pre-operative global and segmental lordosis were 9.39±8.53° and 3.86±4.84°, respectively. At three months postoperatively, global and segmental lordosis were 11.50±10.88° (t-test: p=0.73) and 7.75±5.68° (t-test: p=0.27) respectively. Between the pre-operative and 6-week post-operative appointment, the mean anterior and posterior disc height changes were 5.07±2.99mm and 1.63 ±2.00mm, respectively. Of the 4 patients with repeated imaging at 3 months, 2 (50%) had subsidence over 2mm. At 6-weeks, the radiographic fusion rate was 6/25 (24.0%), which increased to 6/9 (66.7%) at one year.
Conclusion : ACDF with IS is a viable alternative to traditional plate-cage systems for symptomatic ASD. An advantage over traditional plate-cage systems is that removal of prior instrumentation is not needed in order to place implants. While this can provide robust fusion rates, restore cervical lordosis, and increase anterior and posterior disc height, there is a moderate risk for dysphagia, and patients should be appropriately counseled.
