Abstract
Objective: To determine the in vitro difference in stability in a functional spinal unit (FSU) following bilateral laminotomy, and compare it to the instability resulting from laminectomy.
Design: The normal and injured spines were subjected to flexion, extension, lateral bending and torsional moments.
Subjects: Six fresh human cadaver lumbar spines were injured sequentially at the L4–5 level: bilateral laminotomy and laminectomy.
Outcome measures: The three-dimensional motion behaviour of each spine before and after the two injuries was recorded using a magnetic motion sensor. The data from all five spines was pooled for statistical analysis.
Results: With flexion and extension loading, bilateral laminotomy induced significantly less sagittal angulation and translation in the FSU than did laminectomy. Significant increase in coronal translation occurred with laminectomy in spines subjected to lateral bending loads. There were no significant differences between the two techniques in coronal plane angulation with lateral bending loads and torsional loads.
Conclusion: The increase in motion seen with laminectomy in sagittal angulation/translation, and coronal translation in this in vitro model may represent clinical instability, and may be responsible for continued symptomatology in these patients. Preservation of the lamina, spinous processes, and the posterior ligamentous structures significantly enhances the biomechanical stability of the FSU.
Abstracts prepared by Mr. A. J. Stirling, FRCS, and Miss A. Weaver. Correspondence should be addressed to Miss A. Weaver at the Research and Teaching Centre, Royal Orthopaedic Hospital, Northfield, Birmingham, B31 2AP, UK
BritSpine 2002, the second combined meeting of the British Association of Spinal Surgeons, the British Cervical Spine Society, The British Scoliosis Society and the Society for Back Pain Research, took place at the International Convention Centre in Birmingham UK between 27th February and 1st March 2002. The following presentations and posters were given and displayed.
