One-Level Versus 2-Level Treatment With Cervical Disc Arthroplasty or Fusion: Outcomes Up to 7 Years

Area of Science:

• Spine surgery
• Degenerative disc disease
• Cervical spine disorders

Background:

• Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) are established treatments for cervical degenerative disc disease.
• Studies compare the safety and efficacy of single-level versus multi-level procedures for both ACDF and CDA.

Purpose of the Study:

• To compare the safety and efficacy of 1-level versus 2-level cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF).

Main Methods:

• Analysis of 545 (1-level) and 397 (2-level) patients from FDA-approved clinical trials for CDA and ACDF.
• Propensity score method used to adjust for confounding factors.
• Comparison of adjusted mean outcome safety and efficacy scores at 2 and 7 years post-surgery.

Main Results:

• Both 1-level and 2-level CDA and ACDF demonstrated similar improvements in overall success and patient-reported outcomes.
• No significant difference in implant-related adverse events (AEs) or serious AEs between 1-level and 2-level CDA.
• Two-level ACDF showed a higher rate of implant-related AEs at 7 years compared to 1-level ACDF (27.7% vs 18.9%), but serious AEs did not differ significantly.
• Secondary surgery rates were comparable between 1-level and 2-level procedures for both CDA and ACDF at 2 and 7 years.
• Grade IV heterotopic ossification was reported in 4.6% of 1-level CDA patients and 8.6%/7.3% at superior/inferior levels of 2-level CDA patients at 7 years.

Conclusions:

• One-level and 2-level CDA are equally safe and effective for treating cervical degenerative disc disease.
• Two-level ACDF is as effective as 1-level ACDF but associated with a higher incidence of certain adverse events in the long term.