71 patients scheduled for single-level posterior lumbar interbody fusion were randomized to postoperative analgesia, beginning at 36 hours after surgery, with either transdermal buprenorphine patches or oral tramadol. Transdermal buprenorphine patch doses ranged from 5-20ug/hr and were replaced every 7 days, while oral tramadol doses ranged from 150-300mg daily. Patients were assessed for pain scores on a visual analog scale, quality of life, and incidence of adverse events over the first 4 weeks after surgery. Results demonstrated no significant differences between groups in the above outcomes.