Level-specific Perioperative and Clinical Outcome Comparison: Cervical Disk Replacement Versus Anterior Cervical Diskectomy and Fusion at C5-C6 in Patients With Myeloradiculopathy

Introduction: This study compares perioperative and postoperative clinical outcomes in patients undergoing anterior cervical diskectomy and fusion (ACDF) or cervical disk replacement (CDR) at C5-C6 in patients with myeloradiculopathy.

Methods: Primary, elective, single-level CDR or ACDF procedures at C5-C6 for patients with myeloradiculopathy were included. Patient-reported outcome measures (PROMs) included visual analog scale (VAS) neck, VAS arm, Neck Disability Index (NDI), Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), and Short-Form 12-Item Physical Composite Score (SF-12 PCS) collected at preoperative/6-week/12-week/6-month/1-year time points. Surgical cohorts were assessed for differences in demographics/perioperative characteristics using the chi square test and unpaired Student t-test for categorical and continuous variables, respectively. Achievement of minimum clinically important difference (MCID) was determined by comparing ΔPROMs with established thresholds. Outcome measures were compared at postoperative time points with the Student t-test, and improvement from preoperative baseline was assessed with a paired sample t-test.

Results: One hundred thirty-seven patients were included, 43 CDR and 94 ACDF. CDR patients demonstrated significantly reduced surgical times (46.3 versus 55.1 minutes), estimated blood loss (24.4 versus 43.6 mL), revision surgery rates (0.0% versus 5.3%), postoperative length of stay (8.9 versus 23.0 hours), and postoperative narcotic consumption (P < 0.017, all). Complication rates and mean PROMs did not differ between cohorts. The CDR cohort markedly improved from baseline for all PROMs postoperatively except SF-12 PCS/PROMIS-PF at 6 weeks. The ACDF cohort markedly improved at each time point except VAS arm at 1 year, NDI at 6 weeks/1 year, and SF-12 PCS/PROMIS-PF at 6 weeks. A majority of both cohorts achieved overall MCID for VAS neck/NDI/PROMIS-PF. MCID achievement rates did not differ except NDI at 12 weeks/1 year and SF-12 PCS at 6 months, both favoring CDR.

Discussion: Both procedural cohorts demonstrated similar long-term clinical outcomes for arm/neck pain and physical function; however, patients undergoing CDR at C5-C6 demonstrated an improved ability to maintain 1-year postoperative progress for neck disability with improved 1-year NDI MCID achievement. The CDR cohort, in addition, demonstrated an improved perioperative profile and reduced rate of revision surgery.