Post-Laminectomy Spondylolisthesis - A Review of the Posterior Elements and their Contribution to the Stability of the Lumbar Spine

ABSTRACT

As surgical practice changes with increasing new evidence, a review of past experiences often gives us a good idea why we do things the way it is now. Our modern understanding of factors contributing to the stability of the lumbar spine can be represented using posterior decompression of the lumbar spine as an example. Since the late 1900s, the “Christmas tree laminectomy” procedure gained widespread popularity in treating neurogenic claudication and lumbar stenosis. However, this clinical improvement is often transient and patients return with symptom recurrence and findings of spinal instability. Further biomechanical studies and clinical trials looked at modifications to this procedure such as facet sparing laminectomy and laminotomy with improved results. It was then that bony, discoligamentous and muscular factors are increasingly recognized as contributors to the overall stability of the lumbar spine. Surgical decompression of spinal stenosis has to balance between adequate removal of bone and soft tissue for an effective decompression of neural structures, and sufficient retention of bone and soft tissue structures to maintain mechanical stability of the spine. When these stabilizers are compromised, a prophylactic fusion of the spinal unit may be required. Ultimately, the decision to perform laminectomy or laminotomy has to be a clinical judgement based on a combination of surgeon, patient and disease factors.

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