Document Detail


Gravity-induced torque and intravertebral rotation in idiopathic scoliosis.
MedLine Citation:
PMID:  18197088     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
STUDY DESIGN: Biomechanical analysis. OBJECTIVE: To investigate the relationship between gravity-induced torques acting on the scoliotic spine and rotation within the vertebrae. SUMMARY OF BACKGROUND DATA: Vertebral rotation is an important aspect of spinal deformity in idiopathic scoliosis, associated with ribcage asymmetry. Although both lateral curvature and rotation seem to increase together in progressive scoliosis, the mechanisms driving vertebral rotation are not clearly established and it is not known whether lateral curvature precedes rotation, or vice versa. METHODS: Three-dimensional spinal curvature was measured for a small group of idiopathic scoliosis patients using standing radiographs, and equations of static equilibrium were used to calculate gravity-induced torque profiles along the length of each spine because of head, neck, and torso weight. Vertebral rotations were then measured for the same patients using Aaro and Dahlborn's technique with reformatted computed tomography images. The gravity-induced torque curves were compared with rotation measurements to see whether gravity-induced torque is a likely contributor to intravertebral rotation in scoliosis. RESULTS: Gravity-induced torques as high as 7.5 Nm act on the spines of idiopathic scoliosis patients because of body weight in the standing position, and maximum intravertebral rotations (for a single vertebra) are approximately 4 degrees. There is a statistically significant relationship between gravity-induced torque and intravertebral rotation in the scoliotic spine. CONCLUSION: Gravity-induced torque is a likely cause of intravertebral rotation in progressive idiopathic scoliosis. Because the spine must be curved in 3-dimensions (out of plane) to produce such torques, vertebral rotation would be expected to occur subsequent to an initial lateral deviation, suggesting that lateral curvature precedes vertebral rotation in progressive idiopathic scoliosis.
Authors:
Clayton J Adam; Geoffrey N Askin; Mark J Pearcy
Related Documents :
8590488 - Differential effects of ketamine and midazolam on heart rate variability.
3978008 - Continuous extradural infusion of 0.0625% or 0.125% bupivacaine for pain relief in prim...
10903458 - Safety and efficacy of the rapid four-step technique for cricothyrotomy using a bair claw.
22595218 - Factors associated with extreme hyperbilirubinaemia in neonates at the university hospi...
17505188 - An update on the approach to apparent life-threatening events.
1796338 - Maternal-infant separation at birth among substance using pregnant women: implications ...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Spine     Volume:  33     ISSN:  1528-1159     ISO Abbreviation:  Spine     Publication Date:  2008 Jan 
Date Detail:
Created Date:  2008-01-16     Completed Date:  2008-02-14     Revised Date:  2009-07-09    
Medline Journal Info:
Nlm Unique ID:  7610646     Medline TA:  Spine (Phila Pa 1976)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  E30-7     Citation Subset:  IM    
Affiliation:
Paediatric Spine Research Group, Queensland University of Technology and Mater Health Services Brisbane Ltd., Queensland, Australia. c.adam@qut.edu.au
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adolescent
Adult
Child
Compressive Strength
Gravitation*
Humans
Range of Motion, Articular / physiology*
Rotation
Scoliosis / physiopathology*,  radiography
Spine / pathology,  physiopathology*,  radiography
Torque
Weight-Bearing

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Type I hyperprolinemia and proline dehydrogenase (PRODH) mutations in four Italian children with epi...
Next Document:  Enhancing the stability of anterior lumbar interbody fusion: a biomechanical comparison of anterior ...