Fig. 2.

Summary of results from FDA IDE randomized controlled trials (CoE II) reporting rates of symptomatic ASD. NR indicates not reported; ACDF, anterior cervical discectomy and fusion; and C-ADR, cervical total disc arthroplasty.

* Percentages reported at 24 and 48 or 60 months were calculated using the full cohort (n); therefore, the denominator included participants who had either dropped out or had not yet completed follow-up.

^† The article by Mummaneni et al ⁴ is the original report of the FDA IDE study; Burkus et al ³ report the long-term follow-up.