Surgery for degenerative lumbar spondylosis

Surgical investigations and interventions account for as much as one third of the health care costs for spinal disorders, but the scientific evidence for most procedures is still unclear.

Degenerative conditions affecting the lumbar spine are variously described as lumbar spondylosis or degenerative disc disease (which we regarded as one entity) and are associated with back pain, instability, spinal stenosis and degenerative spondylolisthesis. The objective of this review was to assess the effects of surgical interventions for the treatment of degenerative lumbar spondylosis.

We searched the Cochrane Controlled Trials Register, Medline, Embase, Biosis, Dissertation Abstracts, Index to UK Thesis, and reference lists of the retrieved articles and we corresponded with experts. All data found up to 31/12/99 are included.

Randomised or quasi-randomised trials of surgical treatment of lumbar spondylosis

Two reviewers assessed trial quality and extracted data from published papers. Additional information was sought from the authors if necessary.

Sixteen published trials of all forms of surgical treatment for degenerative lumbar spondylosis have been identified. There were many serious weaknesses of trial design, including poor methods of randomisation, lack of blinding and lack of independent assessment of outcome which at times gave considerable potential for bias. Most of the published results were reporting on technical surgical outcomes with some crude ratings of clinical outcome, but few patient-centred outcomes of pain, disability or capacity for work. There was a particular lack of long-term outcomes. This review found no published trials comparing any form of surgery for degenerative lumbar spondylosis compared with natural history, placebo, or any form of conservative treatment. Ten trials randomly compared instrumented and non-instrumented fusion. Instrumented fusion produced a higher fusion rate (though that needs to be qualified by the difficulty of assessing fusion in the presence of metal-work) but did not improve clinical outcomes and there is evidence that it may be associated with higher complication rates. The few and heterogeneous trials on spondylolisthesis, spinal stenosis and nerve compression permitted very limited conclusions.

There is no scientific evidence about the effectiveness of any form of surgical decompression or fusion for degenerative lumbar spondylosis compared with natural history, placebo, or conservative treatment.