Abstract
The purpose of the study is to evaluate the outcome of two methods: Posterolateral fusion and instrumentation versus posterolateral fusion, instrumentation and interbody fusion using clinical and radiological criteria in demographically similar groups. This is a prospective cohort study of sixty-four patients randomized to two therapeutic strategies (Level II study).
Sixty-four patients were randomized to either instrumented posterolateral fusion (control) or combined instrumented posterolateral and interbody fusion (study) in one level degenerative disorders of the lumbar spine. Demographics of the groups were similar including age, gender and other variables. The demographics of the groups were similar for one level degenerative disorders—disc herniation, spondylolisthesis and spinal stenosis. The primary outcome was measured by the Oswestry Disability Index at two years. There was no statistically significant difference. Secondary outcomes (SF36, VAS, fusion rate, disc height maintenance, maintenance of deformity correction, adjacent segment degeneration) were statistically similar in both groups. In conclusion, no clinical advantage with interbody fusion versus posterolateral fusion alone.
Analysis of the correlation between the pedicle shape and the spinal canal anatomy in scoliotic anatomic specimens.
S. Parent1, H. Labelle, W. Skalli, J. de Guise,
13175 Côte Ste-Catherine, Montréal, Québec H3T 1C5.
The objective of the present study was to analyze the correlation between the pedicle shape and spinal canal anatomy in scoliotic specimens. Vertebral canal anatomy was evaluated in a series of thirty anatomic scoliotic specimens and compared to thirty normal specimens. Spinal canal enlargement inversely correlated with pedicle width modifications on the concavity of scoliotic curves. These findings suggest that changes in pedicle anatomy are secondary to local changes in spinal cord position.
Recent studies have demonstrated the close relationship between the spinal cord and the pedicle on the concavity of the scoliotic curve of patients with scoliotic deformities. The hypothesis of the present study is that changes in spinal canal shape are related to spinal cord position and resulting bone remodeling. This study evaluated the characteristic changes of spinal canal shape in anatomic scoliotic specimens.
Posterior elements morphology is closely related to the local spinal cord anatomy and its relationship with the bony architecture.
The characteristic posterior element changes seen in scoliosis are likely the result of local bone remodeling.
Spinal asymmetry was observed in scoliotic specimens when compared to normal specimens. Spinal canal was enlarged asymmetrically on the concavity of thoracic scoliotic curves (p < 0.01). Overall, canal surface was greater in scoliotic specimens when compared to normal specimens (p < 0.01). These changes were more important at the apex of the curve.
Spinal canal characteristic shape was evaluated in thirty scoliotic anatomic specimens and thirty normal anatomic specimens using twelve parameters representing measures of right and left hemi-canal length, width or surface area. The 3-D coordinates of eight points taken at the periphery of each spinal canal were recorded.
The results of this study support the hypothesis that spinal canal shape is modified by the spinal cord position and that posterior element changes seen in scoliosis are in part due to bone remodeling in response to local neural anatomy modifications.
Funding: Fonds de Recherche en Santé du Québec
Correspondence should be addressed to Cynthia Vezina, Communications Manager, COA, 4150-360 Ste. Catherine St. West, Westmount, QC H3Z 2Y5, Canada
