1490. Assessing the Differences in 30-day Clinical and Surgical Outcomes between Repeat Cervical Disc Arthroplasty and Repeat Cervical Fusion: Results from a National Surgical Registry

Authors: Mohamad Bydon, MD, FAANS ; Mohammed Ali Alvi, MD; Anshit Goyal, MD; Brett Freedman, MD; Bradford Currier, MD; Benjamin Elder, MD, PhD (Rochester, MN)

Introduction: Anterior Cervical Discectomy and Fusion (ACDF) and Cervical Disc Arthroplasty (CDA) are two commonly employed procedures for surgical management for Cervical Spondylotic Myelopathy. However, reoperations after both these procedures are common; the rate ranges from 8-12% for ACDF and from 4-6% for CDA. Literature regarding outcomes for revision procedures after ACDF and CDA is sparse. Methods: We queried the National Surgical Quality Improvement Program (NSQIP) for patients undergoing removal/repeat 1-2 level ACDF/Posterior Cervical Fusion (PCF) and CDA using CPT codes between 2012 and 2016. Patients with a history of hybrid procedure (ACDF/PCF and CDA) at the index operation were excluded. Demographic characteristics, baseline clinical characteristics, postoperative diagnosis and 30-day outcomes were compared between revision/removal ACDF and CDA. Results: A total of 104 repeat cervical arthroplasty procedures were identified, of which 14.4% (n=15) were removal alone, 44.2% (n=32) were revision arthroplasty alone, 26% (n=27) were removal of arthroplasty and fusion and 15.3% (n=16) were repeat arthroplasty and fusion (hybrid procedure). A total of 670 1-2 level repeat fusion procedures were identified, of which 14.2%(n=95) were removal of instrumentation alone while 85.2%(n=575) were revision fusion; among revision fusion cases, 72% (n=414) were anterior, 18.4% (n=106) were posterior while 7.1% (n=41) were circumferential fusions. On univariate analysis, patients undergoing repeat arthroplasty procedures were younger (Mean age 48.7±12.2 years vs 56.4.7±10.5, p<0.001), more likely to have a postoperative diagnosis of instrument related complication (21.2% vs 12.7%, p<0.001), had shorter operative time (139.1 minutes±78.9 vs 181.2 minutes±104.2, p<0.001) and shorter LOS (1.8 days±1.9 vs 3.3 days±6.1, p=0.008). Readmission-rate was not found to be significantly different between the two groups (6.7%, n=7 vs 5.1%, n=34, p=0.48) Conclusion: Our results indicate that while there may be difference in patient characteristics and indications for 1-2 level repeat arthroplasty/fusions both can be performed safely with favorable 30-day outcomes