Experimental Design of Total Disk Replacement—Experience with a Prospective Randomized Study of the SB Charitè

STUDY DESIGN: Prospective randomized clinical trial. OBJECTIVES: To determine if a prospective randomized study of patients with symptomatic degenerative disc disease treated with disc arthroplasty could be safely completed. METHODS: Sixty patients with one-level discogenic pain confirmed by plain radiography, magnetic resonance imaging, and provocative discography for degenerative disc disease were randomized comparing 1/3 BAK anterior interbody fusion and 2/3 anterior SB Charitè artificial disc replacement. RESULTS: 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 Charitè 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 cc (range 50-1800 cc). The length of hospital stay was a mean of 3.03 days (range 2 to 6 days). Oswestry Disability Index for the BAK control group was 45.9 +/- 10.4 before surgery and 23.5 +/- 17.2 at follow-up (P < 0.001). The corresponding ODI scores for the SB Charitè disc were 50.0 +/- 14.3 before surgery and 25.0 +/- 20.1 at a mean of 2 years' follow-up (P < 0.001). CONCLUSIONS: This is the first study that shows improvement of functional outcome measures in a prospective randomized design treating primarily mechanical back pain and achieving comparable successful results to lumbar spinal stenosis decompression.