Document Detail

Stress analysis of a partially slotted intramedullary nail.
MedLine Citation:
PMID:  6527162     Owner:  NLM     Status:  MEDLINE    
A finite element analysis of the Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF) intramedullary femoral nail was performed to study the failure of the nail from circumferential cracking near the slot tip. These failures are evidently the result of a stress-concentrating effect owing to the partially slotted nail design. Several finite element models were created of the proximal one-fourth of the nail. One model of the nail incorporated the cloverleaf profile as it is presently manufactured, and one had a circular cross section. An additional three models were created with alternative slot-tip geometries: a narrowed slot, a tapered slot, and a widened slot. Antero-posterior (AP) and medio-lateral (ML) bending loads and torsion loads were applied in two fundamentally different loading modes: (1) loads that were applied on both sides of the slot tip (spanned); and (2) loads that were self-equilibrating distal to the slot tip (non-spanned). For the load cases studied, for all models, the stresses predicted from the finite element models were locally highest at the junction between the open and closed cross sections. Alternative slot-tip shapes had a marked effect on the predicted stresses, in one case reducing maximum stress by 40%. However, no alternative slot tip shape was uniformly superior for all load cases. Therefore, until the in vivo loading modes are known more precisely, an alternative slot-tip shape cannot be proposed.
G S Beaupré; E Schneider; S M Perren
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of orthopaedic research : official publication of the Orthopaedic Research Society     Volume:  2     ISSN:  0736-0266     ISO Abbreviation:  J. Orthop. Res.     Publication Date:  1984  
Date Detail:
Created Date:  1985-04-03     Completed Date:  1985-04-03     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8404726     Medline TA:  J Orthop Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  369-76     Citation Subset:  IM    
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MeSH Terms
Bone Nails*
Equipment Design
Equipment Failure
Fracture Fixation, Intramedullary / instrumentation*
Stress, Mechanical*

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