Linked Life Data

15994054

Source:http://linkedlifedata.com/resource/pubmed/id/15994054

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-10-17
pubmed:abstractText
Previous mechanical studies concerning cut-out of lag screws for pertrochanteric hip fractures have relied on static or dynamic uniaxial loading regimens to induce construct failure by varus collapse and superior cut-out. However, the hip is loaded in a multiplanar, dynamic manner during normal gait. We designed a hip implant performance simulator (HIPS) system to evaluate lag screw cut-out under multiplanar loading representative of normal gait. Five surrogate pertrochanteric fracture specimens with lag screw fixation were loaded up to 20,000 cycles using a biaxial rocking motion (BRM) gait simulation protocol. Another five specimens were loaded using a standard uniaxial loading protocol. The BRM loading group exhibited combined varus collapse (5.4+/-2.9 degrees ) and backward rotation (7.2+/-2.8 degrees ). The uniaxial loading group exhibited four times less varus collapse (1.4+/-1.1 degrees ) as compared to the BRM group, and only negligible rotation. For correlation of lag screw migration in surrogate specimens to that in native bone, six human cadaveric specimens were subjected to BRM loading. The degree of varus collapse (8.5+/-7.7 degrees ) and rotation (7.2+/-6.4 degrees ) in cadaveric specimens were comparable to that in surrogate specimens, with the surrogate specimens showing significantly less variability. The results demonstrate that accounting for clinically realistic multiplanar loading vectors significantly affects implant migration, and therefore should be considered when evaluating the fixation strength of hip screw implants.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0736-0266
pubmed:author
pubmed:issnType
Print
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1329-35
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Lag screws for hip fracture fixation: Evaluation of migration resistance under simulated walking.
pubmed:affiliation
Biomechanics Laboratory, Legacy Clinical Research and Technology Center, 1225 NE 2nd Ave., Portland, OR 97232, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't