A study published in Spine examines the four-year outcomes for patients with one- and two-level total disc replacements.
The patients were enrolled in an FDA investigational device exemption clinical trial for cervical disc replacement. The patients were randomized to either disc replacement or anterior cervical discectomy and fusion at one of 24 sites. There were 164 patients who underwent disc replacement.
There were also 24 patients who underwent disc replacement as training cases.
The researchers found:
1. The preoperative characteristics were statistically similar for one- and two-level patient groups.
2. Four years after surgery, there was no statistically significant differences between the one- and two-level patients in the total disc replacement group for all clinical outcomes measures.
3. Both groups of disc replacement patients experienced improvement at each follow-up when compared with the preoperative scores.
4. There was one case of migration in the two-level disc replacement group.
5. There wasn't a statistically significant difference in complication rate or subsequent surgery rate in the disc replacement group across all 24 sites.