Comparison of Two-Level versus One-Level Total Disc Replacement: Results from a Prospective FDA-Regulated Trial
SAS Journal, 2008; 140-144
Jack E. Zigler, Donna D. Ohnmeiss
Lumbar Total Disc Replacement , Degenerative Disc Disease
Fusion has been the traditional surgery for painful disc degeneration unresponsive to non-operative care. Fusion rates may decline in multilevel procedures. Also, fusion may force additional stress onto adjacent discs. This effect may be amplified in multilevel procedures. Single-level total disc replacement (TDR) has been found to be as effective as fusion. There have been few published reports addressing two-level TDR. The purpose of this study was to compare results of TDR at two levels to one-level procedures.
This report included the first consecutive 86 patients who had reached 24-month follow-up from among those enrolled in the ProDisc-L investigational device exemption (IDE) study of patients undergoing TDR at one level (N = 54) or at two levels (N = 32). Clinical outcome measures included visual analog scales (VAS) assessing pain, Oswestry Disability Index, satisfaction measured by VAS and responses to the question regarding whether the patient would have the same surgery again.
Operative time and length of hospitalization were significantly less in the one-level cases compared to two levels (61.6 minutes versus 97.8 minutes, and 1.89 days versus 2.44 days; p < .05). There was a trend for less blood loss in single-level cases (59.0 mL versus 79.2 mL) (.05 < p < .09). VAS and Oswestry scores were significantly improved in both groups postoperatively (by approximately 50%). At no follow-up were there significant differences in VAS, Oswestry or patient satisfaction scores between the single- and two-level patients. At all follow-ups, the mean satisfaction in both groups was greater than 7.5 on a scale of 0 to 10.
Patients undergoing two-level TDR improved significantly postoperatively based on VAS and Oswestry scores, and there were no significant differences in outcome scores when comparing one- and two-level TDR.