Two-level total disc replacement vs. fusion: any difference in reoperation rate?

In this issue of the Clinical Spine Surgery, Radcliff et al. report on the results of five-year follow-up of reoperation rates in a prospective and randomized trial comparing 2-level lumbar total disc replacement (TDR) vs. fusion. 2-level lumbar TDR is a relatively novel procedure and its role in the surgical treatment of degenerative disc disease (DDD) should be fully scrutinized in comparison to 2-level fusion. However, it should be uncommon for an investigator to hold a well-controlled prospective randomized study with appropriate number of patients in long-term follow-up. Au fond there are few high-level studies reporting long-term reoperation rates in comparison between 2-level TDR and 2-level fusion. The current study comparing 2-level TDR and fusion in many patients is certainly a high-level and rare study despite its limitations, as this study includes well controlled, randomized, and longer-term follow-up research compared to the other relevant studies in the literature. As the authors indicated, this study was based on a US Food and Drug Administration (FDA) investigational device exemption comparing TDR to fusion for the treatment of symptomatic 2-level contiguous lumbar DDD.