BACKGROUND: Using a tethering technique, a porcine model of scoliosis has been created. Ideally, tether release before placement and evaluation of corrective therapies would lead to persistent scoliosis. QUESTIONS/PURPOSES: Does release of the spinal tether result in persistent deformity? METHODS: Using a unilateral spinal tether and ipsilateral rib cage tethering, scoliosis was initiated on seven pigs. The spinal tether was released after progression to a Cobb angle of 50°. Biweekly radiographs were taken for 18 weeks after tether release to evaluate longitudinal changes in coronal and sagittal Cobb angles. Postmortem fine-cut CT scans were used to evaluate vertebral and disc wedging and axial rotation; results were compared to a previously published data set of 11 animals euthanized before release of the tether (control group). RESULTS: Radiographic analysis demonstrated two responses to tether release: a persistent deformity group and an autocorrective group. Differences between these two groups included number of days with the tether in place before reaching a Cobb angle of 50° and degree of deformity immediately after scoliosis induction. CT analysis of the tether release versus tether intact groups demonstrated progression in vertebral body wedging without differences in apical rotation. CONCLUSIONS: With the appropriate inducing parameters, release of the spinal tether does not systematically result in deformity correction. Tether release resulted in a reduction in Cobb angle in the first several weeks followed by steady curve progression. Deformity progression was confirmed using detailed CT morphometric analysis.
BACKGROUND: Using a tethering technique, a porcine model of scoliosis has been created. Ideally, tether release before placement and evaluation of corrective therapies would lead to persistent scoliosis. QUESTIONS/PURPOSES: Does release of the spinal tether result in persistent deformity? METHODS: Using a unilateral spinal tether and ipsilateral rib cage tethering, scoliosis was initiated on seven pigs. The spinal tether was released after progression to a Cobb angle of 50°. Biweekly radiographs were taken for 18 weeks after tether release to evaluate longitudinal changes in coronal and sagittal Cobb angles. Postmortem fine-cut CT scans were used to evaluate vertebral and disc wedging and axial rotation; results were compared to a previously published data set of 11 animals euthanized before release of the tether (control group). RESULTS: Radiographic analysis demonstrated two responses to tether release: a persistent deformity group and an autocorrective group. Differences between these two groups included number of days with the tether in place before reaching a Cobb angle of 50° and degree of deformity immediately after scoliosis induction. CT analysis of the tether release versus tether intact groups demonstrated progression in vertebral body wedging without differences in apical rotation. CONCLUSIONS: With the appropriate inducing parameters, release of the spinal tether does not systematically result in deformity correction. Tether release resulted in a reduction in Cobb angle in the first several weeks followed by steady curve progression. Deformity progression was confirmed using detailed CT morphometric analysis.
Authors: Randal R Betz; John Kim; Linda P D'Andrea; M J Mulcahey; Rohinton K Balsara; David H Clements Journal: Spine (Phila Pa 1976) Date: 2003-10-15 Impact factor: 3.468
Authors: John T Braun; James W Ogilvie; Ephraim Akyuz; Darrel S Brodke; Kent N Bachus; Raymond M Stefko Journal: Spine (Phila Pa 1976) Date: 2003-10-01 Impact factor: 3.468
Authors: John G Burke; Enzo Vettorato; Gudrun Schöffmann; R Eddie Clutton; Tim S Drew; J N Alastair Gibson Journal: Eur Spine J Date: 2014-10-16 Impact factor: 3.134
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