7 randomized controlled trials (1,584 patients) comparing spinal fusion with total disc replacement (TDR) in patients with degenerative disc disease were included in this review, to compare these two treatment approaches with respect to clinical efficacy and safety assessed for up to 2 years. Results indicated that although pain and function were found to be statistically superior in the TDR group compared to the fusion group, these results were not found to be clinically significant. Hospital stay and patient satisfaction were also statistically superior in the TDR group. Lastly, there were no significant between-group differences in operation time, blood loss, complications, reoperation rates or the proportion of patients who returned to work.