Outcome measures: The primary outcome was the Oswestry Disability Index (ODI, 0–100 scale) at 2 years. Secondary outcomes included low back pain (0–100 VAS), SF-36, and EQ-5D scores. Results: The drop-out rate at 2 years was 15% in the surgical arm and 24% in the rehabilitation arm. At 2 years follow up, the between group differences (95% CI) in favour of the surgical treatment were −8.4 (−13.2 to −3.6) for ODI, −12.2 (−21.3 to −3.1) for pain, and 5.8 (2.5 to 9.1) for SF-36 physical health summary. No differences were found in SF-36 mental health summary or EQ-5D. Conclusion: Surgery SCH 900776 mouse with disc

prosthesis produced significantly greater improvement in variables measuring physical disability and pain, but the difference in ODI between groups did not exceed

the pre-specified minimally important difference of 10 points, so it is unclear whether selleck screening library the observed changes were clinically meaningful. Disc replacement in chronic low back pain has shown promising results during the past decades, showing at least equivalent effects to that of fusion surgery (Berg et al 2009). The present study represents an important contribution comparing surgery with disc prosthesis with multidisciplinary rehabilitation. This well-designed and executed multicentre study demonstrates that surgery is superior to multidisciplinary treatment when measured by disability and pain, but the difference in the main outcome Oswestry of 8.4 points was smaller than the difference of 10 points that the study was designed to detect. As there is no consensus regarding how large the difference between groups must be in order to demonstrate clinical importance, it is not possible much to conclude that the difference in effect in this study is of clinical importance.

However, clinical important improvement for one individual was defined as 15 points on Oswestry, and 70% in the surgical group versus 47% in the rehabilitation group achieved this improvement, supporting the positive effect of disc replacement. It should also be mentioned that both groups experienced considerable improvement. A limitation of the study is the lack of a control group. The placebo effect might have been higher in the surgery group due to patient expectation of surgery, although possible placebo effects after several weeks of personal contact during rehabilitation should not be underestimated, and these effects may be counterbalanced. Indications were found that patients with Modic I and II disc changes may have a superior result in the surgery arm while patients with a high Oswestry score may be more suitable for rehabilitation, and this result underlines that it is important to select treatment individually for each patient. Surgery carries a risk of serious complications and these occurred in one patient in the study.