TY - JOUR
T1 - Structural stiffness and reducibility of external fixators placed in malalignment and malrotation
AU - Carmack, David B.
AU - Kaylor, Kenneth L.
AU - Yaszemski, Michael J.
PY - 2001
Y1 - 2001
N2 - Objective: To determine the structural stiffness and reducibility of various external fixators placed in malalignment and malrotation. Design: Uniform testing of all external fixator configurations. Setting: Orthopaedic biomechanical laboratory. Methods: Thirteen external fixators from different manufacturers, in a total of fifteen configurations, were studied. All external fixators were applied to a malreduction jig initially, and a subsequent anatomic reduction was then attempted. If an anatomic reduction was possible, the structural stiffness of those fixators was determined. If anatomic reduction was not possible, the external fixator was removed and reapplied to an anatomically reduced model, and then structural stiffness was determined. Results: Six of the thirteen external fixator configurations, allowed an anatomic reduction after placement on a malreduction model. The other nine external fixator configurations would not allow for an anatomic reduction. All the external fixator configurations were biomechanically tested in anteroposterior bending, lateral bending, axial load, and torsion. Each fixator had its own structural stiffness and is reported. Conclusions: Some external fixators will not allow for an anatomic reduction once placed in malalignment and malrotation without repositioning of the fixator pins. External fixator configurations (i.e., single-pin, dual-pin, and multipin barclamps) affect structural stiffness. Structural stiffness widely varied among the external fixators. Proper external fixator selection will enable early fracture immobilization in malalignment and malrotation in suboptimal conditions (e.g., wartime conditions or a civilian disaster), with subsequent external fixator adjustment for an anatomic reduction.
AB - Objective: To determine the structural stiffness and reducibility of various external fixators placed in malalignment and malrotation. Design: Uniform testing of all external fixator configurations. Setting: Orthopaedic biomechanical laboratory. Methods: Thirteen external fixators from different manufacturers, in a total of fifteen configurations, were studied. All external fixators were applied to a malreduction jig initially, and a subsequent anatomic reduction was then attempted. If an anatomic reduction was possible, the structural stiffness of those fixators was determined. If anatomic reduction was not possible, the external fixator was removed and reapplied to an anatomically reduced model, and then structural stiffness was determined. Results: Six of the thirteen external fixator configurations, allowed an anatomic reduction after placement on a malreduction model. The other nine external fixator configurations would not allow for an anatomic reduction. All the external fixator configurations were biomechanically tested in anteroposterior bending, lateral bending, axial load, and torsion. Each fixator had its own structural stiffness and is reported. Conclusions: Some external fixators will not allow for an anatomic reduction once placed in malalignment and malrotation without repositioning of the fixator pins. External fixator configurations (i.e., single-pin, dual-pin, and multipin barclamps) affect structural stiffness. Structural stiffness widely varied among the external fixators. Proper external fixator selection will enable early fracture immobilization in malalignment and malrotation in suboptimal conditions (e.g., wartime conditions or a civilian disaster), with subsequent external fixator adjustment for an anatomic reduction.
KW - External fixator
KW - Tibia fracture
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U2 - 10.1097/00005131-200105000-00003
DO - 10.1097/00005131-200105000-00003
M3 - Article
C2 - 11371789
AN - SCOPUS:0034952157
SN - 0890-5339
VL - 15
SP - 247
EP - 253
JO - Journal of orthopaedic trauma
JF - Journal of orthopaedic trauma
IS - 4
ER -