80 patients with chronic back pain and single-level degenerative disc disease were randomized to receive posterior lumbar interbody fusion with or without additional pedicle screw fixation. The purpose of this study was to compare radiological and clinical outcomes of Trabecular Metal spacers in terms of their ability to achieve a stable construct up to 6-years postoperatively. Results at 6-years displayed a similar rate of stable construct achieved in patients treated with trabecular metal spacers alone in comparison to those receiving additional pedicle screw fixation. Significant improvements were noted in both groups in terms of pain and function scores up to 24-months postoperatively, with no differences between groups.