Comparing Nonrandomized Observational Studies With Randomized Controlled Trials in Cervical Disc Arthroplasty: A Meta-analysis.

Study Design: Systematic review and meta-analysis.

Objective: To compare the treatment effects of observational studies versus randomized controlled trials (RCTs) in cervical disc arthroplasty.

Summary Of Background Data: RCTs can be logistically challenging and sometimes insufficiently generalizable; well-designed observational studies have been suggested as an alternative.