The effect of bilateral laminotomy versus laminectomy on the motion and stiffness of the human lumbar spine: a biomechanical comparison

• Published in: Spine (Philadelphia, Pa. 1976) Pa. 1976), 2010-09, Vol.35 (19), p.1789-1793
• Main Authors: Lee, Michael J, Bransford, Richard J, Bellabarba, Carlo, Chapman, Jens R, Cohen, Amy M, Harrington, Richard M, Ching, Randal P
• Format: Article
• Language: English
• Subjects: Aged; Biomechanical Phenomena; Cadaver; Decompression, Surgical - adverse effects; Decompression, Surgical - methods; Humans; Joint Instability - etiology; Joint Instability - physiopathology; Joint Instability - prevention & control; Laminectomy - adverse effects; Laminectomy - methods; Lumbar Vertebrae - physiopathology; Lumbar Vertebrae - surgery; Range of Motion, Articular; Spondylolisthesis - etiology; Spondylolisthesis - physiopathology; Spondylolisthesis - prevention & control
• ISSN: 0362-2436; 1528-1159
• DOI: 10.1097/BRS.0b013e3181c9b8d6

A cadaveric simulation model of the lumbar spine was used to study the intervertebral motion characteristics of the lumbar spine after bilateral laminotomy and facet-sparing laminectomy. To assess differences in motion patterns and lumbar spine stiffness after bilateral laminotomy versus laminectomy. Spondylolisthesis after facet-sparing laminectomy has been reported with a frequency of 8% to 31%. Bilateral laminotomies have been shown to be effective in decompressing the spine, without resection of the posterior osteo-ligamentous complex. We hypothesize that bilateral laminotomies induce significantly less iatrogenic hypermobility and less stiffness reduction than a traditional facet-sparing laminectomy in the lumbar spine. Six fresh frozen human cadaveric lumbar spines (L1-L5) were mounted into a spine motion simulator for testing. With physiologic follower preload, flexion/extension, lateral bending, and axial rotation moments were applied to the lumbar spine in 3 trials: (1) Intact lumbar spine-no surgery, (2) Lumbar spine after bilateral lumbar laminotomies at L2-L5, (3) Lumbar spine after full laminectomies at L2-L5. The lumbar spine kinematics were measured using a Vicon motion tracking system. Total and segmental range of motion and spine stiffness were recorded. In flexion/extension, bilateral laminotomies resulted in an average increase in L2-L5 range of flexion/extension motion of 14.3%, whereas a full laminectomy resulted in an increase of 32.0% (P