Linked Life Data

12771819

Source:http://linkedlifedata.com/resource/pubmed/id/12771819

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
410
pubmed:dateCreated
2003-5-28
pubmed:abstractText
Rotational stresses from box-post impingement have been implicated in the loosening of posterior-stabilized total knee prostheses. A bench model was constructed to assess the forces generated by tibiofemoral rotation. Rotational torque under load was measured in two different posteriorstabilized total knee prostheses using an axial-torsion load cell at 0 degrees, 20 degrees, and 40 degrees flexion over 20 degrees internal and external rotation. The Sigma posterior-stabilized prosthesis generated little torque through 5 degrees internal and external rotation. An increase in torque then occurred because of box-post impingement, generating peak torques of 17 to 18 N-m at 12 degrees to 14 degrees rotation. The bench model produced the same deformation of the polyethylene post as seen on retrieved specimens. The Scorpio posterior-stabilized prosthesis had a relatively continuous rise in generated torque from tibiofemoral conformity. Box-post impingement did not occur resulting in 32% lower torque between 12 degrees and 14 degrees rotation. Peak rotational torques of 15 to 16 N-m were reached at 19 degrees to 20 degrees rotation. Tibiofemoral conformity is the primary source of rotational constraint. Box-post impingement can be a source of additional rotational constraint. Depending on specific design features, small changes in relative tibiofemoral component rotation can more than double the generated torque. Axial rotation of the knee in vivo can generate substantial torque. Relative tibiofemoral rotational position is an important factor influencing component function and fixation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0009-921X
pubmed:author
pubmed:issnType
Print
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
82-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Rotational constraint in posterior-stabilized total knee prostheses.
pubmed:affiliation
Stryker Howmedica Osteonics Corp., Allendale, NJ, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't