There is not good evidence to support different approaches to fusion, and the evidence to support any surgery at all is weak. This is a good review of the literature regarding fusion (not specifically 3 level fusion):
TI Surgery for degenerative lumbar spondylosis: updated Cochrane Review.
AU Gibson JN; Waddell G
SO Spine 2005 Oct 15;30(20):2312-20.
STUDY DESIGN: An updated Cochrane review. OBJECTIVE: To review current scientific evidence on the effectiveness of surgical interventions for degenerative lumbar spondylosis. SUMMARY OF BACKGROUND DATA: There is still limited scientific evidence on spinal surgery. METHODS: Use of standard Cochrane review methods to analyze all randomized controlled trials published to March 31, 2005. RESULTS: A total of 31 randomized controlled trials were identified. Most of the earlier trials reported mainly surgical outcomes; more of the recent trials also reported patient-centered outcomes of pain or disability. There is still very little information on occupational outcomes or long-term outcomes beyond 2-3 years. Seven heterogeneous trials on spondylolisthesis, spinal stenosis, and nerve compression permitted limited conclusions. There were two new trials on fusion that showed conflicting results. One trial showed that fusion gave better clinical outcomes than conventional physiotherapy, and the other showed that fusion was no better than a modern exercise and rehabilitation program. There were 8 trials that showed that instrumented fusion produces a higher fusion rate, but any improvement in clinical outcomes is probably marginal. CONCLUSIONS: No conclusions are possible about the relative effectiveness of anterior, posterior, or circumferential fusion. The preliminary results of three small trials of intradiscal electrotherapy suggest it is ineffective, except possibly in highly selected patients. Preliminary data from three trials of disc arthroplasty do not permit firm conclusions.
AD The Spinal Unit, The Royal Infirmary of Edinburgh, The University of Edinburgh, Edinburgh, United Kingdom. j.n.a.gibson @ ed.ac.uk
should I have my cage removed after 7 years since I had my fusion?