External fixators for pelvic fractures: comparison of the stiffness of current systems.
We evaluated the stiffness of external fixation (EF) systems with a reproducible, standardized human pelvic replica of aluminum and perspex in which a type C pelvic ring injury was created. 12 EF systems were analyzed in 2 situations that necessarily occur during a walking cycle. Endpoints were defined as 15 mm of dislocation or tolerance of the maximum load in each situation. In the no weightbearing situation, all except 2 fixators failed; in the weightbearing situation, all fixators failed. Single bar systems performed better than frame configurations. Stability provided by any external fixator is low, and in the case of a type C pelvic ring injury, it is insufficient for patient mobilization and weightbearing. Single bar systems provide more stability than frames.
Ponsen
Kees J
KJ
Department of Traumatology, Academisch Medisch Centrum, University of Amsterdam, Amsterdam, The Netherlands. K.J.Ponsen@amc.uva.nl
Hoek van Dijke
Gilbert A
GA
Joosse
Pieter
P
Snijders
Chris J
CJ
D001696:Biomechanical Phenomena; D004548:Elasticity; D004867:Equipment Design; D016267:External Fixators; D050723:Fractures, Bone / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D066298:In Vitro Techniques; D008953:Models, Anatomic; D010384:Pelvic Bones / Q000293:injuries* / Q000503:physiopathology; D016474:Weight-Bearing