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A biomechanical study on fixation stability with twin hook or lag screw in artificial cancellous bone

Olsson, O; Tanner, KE; Ceder, L and Ryd, Leif LU (2002) In International Orthopaedics 26(6). p.349-355
Abstract
The twin hook has been developed as an alternative to the conventional lag screw to be combined with a barrelled side-plate in the treatment of trochanteric hip fractures. With two oppositely directed apical hooks introduced into the subchondral bone of the femoral head, the twin hook provides different stabilising properties to the lag screw. The femoral head purchase of the twin hook and the lag screw were compared in a biomechanical study using artificial cancellous bone, and responses to axial and torsional loading was determined. A distinct yield point in load and torque was noted for the lag screw, representing failure of the laminas supporting the threads. For the twin hook, gradual increase of load and torque occurred during... (More)
The twin hook has been developed as an alternative to the conventional lag screw to be combined with a barrelled side-plate in the treatment of trochanteric hip fractures. With two oppositely directed apical hooks introduced into the subchondral bone of the femoral head, the twin hook provides different stabilising properties to the lag screw. The femoral head purchase of the twin hook and the lag screw were compared in a biomechanical study using artificial cancellous bone, and responses to axial and torsional loading was determined. A distinct yield point in load and torque was noted for the lag screw, representing failure of the laminas supporting the threads. For the twin hook, gradual increase of load and torque occurred during impaction of the bone supporting the hooks. The peak loads and torques were higher for the lag screw, but were similar for both devices after 8 rum deformation. The stiffness was higher for the lag screw, but in counter-clockwise rotation the stiffness for the lag screw was negligible. The twin hook appeared to provide fixation stability comparable to that offered by the lag screw, but with conceivable advantages in terms of a deformation response involving bone impaction and gradually increasing stability. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Orthopaedics
volume
26
issue
6
pages
349 - 355
publisher
Springer
external identifiers
  • wos:000180040700006
  • pmid:12466867
  • scopus:12244293842
ISSN
1432-5195
DOI
10.1007/s00264-002-0385-x
language
English
LU publication?
yes
id
86084fb3-4815-4fb8-b9d3-21acd63b4fbb (old id 320684)
date added to LUP
2007-11-08 08:33:50
date last changed
2017-08-13 04:29:00
@article{86084fb3-4815-4fb8-b9d3-21acd63b4fbb,
  abstract     = {The twin hook has been developed as an alternative to the conventional lag screw to be combined with a barrelled side-plate in the treatment of trochanteric hip fractures. With two oppositely directed apical hooks introduced into the subchondral bone of the femoral head, the twin hook provides different stabilising properties to the lag screw. The femoral head purchase of the twin hook and the lag screw were compared in a biomechanical study using artificial cancellous bone, and responses to axial and torsional loading was determined. A distinct yield point in load and torque was noted for the lag screw, representing failure of the laminas supporting the threads. For the twin hook, gradual increase of load and torque occurred during impaction of the bone supporting the hooks. The peak loads and torques were higher for the lag screw, but were similar for both devices after 8 rum deformation. The stiffness was higher for the lag screw, but in counter-clockwise rotation the stiffness for the lag screw was negligible. The twin hook appeared to provide fixation stability comparable to that offered by the lag screw, but with conceivable advantages in terms of a deformation response involving bone impaction and gradually increasing stability.},
  author       = {Olsson, O and Tanner, KE and Ceder, L and Ryd, Leif},
  issn         = {1432-5195},
  language     = {eng},
  number       = {6},
  pages        = {349--355},
  publisher    = {Springer},
  series       = {International Orthopaedics},
  title        = {A biomechanical study on fixation stability with twin hook or lag screw in artificial cancellous bone},
  url          = {http://dx.doi.org/10.1007/s00264-002-0385-x},
  volume       = {26},
  year         = {2002},
}