Sixty patients with one-level discogenic pain confirmed by plain radiography, magnetic resonance imaging, and provocative discography for degenerative disc disease were randomized: one-third BAK anterior interbody fusion and two-thirds anterior SB Charité artificial disc replacement. The mean age was 40.3 years (range 21-56 years). Nineteen cases were at L4-L5 and 41 cases were at L5-S1. Nineteen cases had BAK anterior interbody fusion and 41 cases were randomized as SB Charité disc replacement. The length of surgery was mean 88.4 minutes (range 54-137 minutes) for both groups. The estimated blood loss was mean 289.5 mL (range 50-1800 mL). The length of hospital stay was a mean of 3.03 days (range 2-6 days). Oswestry Disability Index scores for the SB Charité disc (aggregate study group) were 50.0 +/- 14.3 preoperatively and 25.0 +/- 20.1 at 1-3 years' follow-up (P < 0.001). This is the first study that shows improvement of functional outcome measures in a prospective randomized design with disc arthroplasty treating primarily mechanical back pain and achieving comparable successful results to lumbar fusion-interbody fusion cage and BMP or interbody autograft and pedicle screw instrumentation.