[Three-dimensional measurement of fracture gap motion. Biomechanical study of experimental tibial fractures with anterior clasp fixator and ring fixator].
A computer-linked magnetic motion tracker was used to monitor the six components of elastic fracture motions in cadaver tibia with simulated mid-shaft oblique fractures or segmental defects. The limbs were mounted in a servo-hydraulic load frame and stabilized with an Ilizarov frame or an AO-Unifix external fixator. A cyclic load of 150 or 300 N was applied along the long axis of the tibia. Under 150 N load, elastic displacements ranged up to 1.7 mm and elastic rotations ranged up to 0.6 degrees. Under 300 N load, elastic displacements went up to 3.6 mm and elastic rotations ranged up to 1.5 degrees. Comparison of the two fixators showed that the Ilizarov permitted up to 1.75 times more axial pistoning and up to 4 times more A-P displacement. The AO-Unifix permitted up to 4 times more varus-valgus and up to 7 times more A-P angulation. The technique developed for measuring the three-dimensional motion of fractures may have wide applications in further biomechanical and fracture healing studies.
Unfallchirurgische Klinik, Medizinischen Hochschule Hannover.
R
R
Hoffmann
H A
HA
McKellop
A
A
Sarmiento
B
B
Lu
E
E
Ebramzadeh
D001696:Biomechanical Phenomena; D004548:Elasticity; D004867:Equipment Design; D016267:External Fixators; D006801:Humans; D012399:Rotation; D013978:Tibial Fractures / Q000503:physiopathology* / Q000601:surgery; D014945:Wound Healing
Dreidimensionale Messung von Frakturspaltbewegungen. Biomechanische Studie an experimentellen Unterschenkelfrakturen mit ventralem Klammerfixateur und Ringfixateur.