Intramedullary rod fixation compared with blade-plate-and-screw fixation for tibiotalocalcaneal arthrodesis: a biomechanical investigation.
BACKGROUND
Achieving stable fixation when performing tibiotalocalcaneal arthrodesis can be challenging, especially in osteopenic bone. The purpose of the current investigation was to compare the stiffness and fatigue endurance of blade-plate-and-screw fixation with intramedullary rod fixation in a cadaveric model.


METHODS
In ten matched pairs of fresh-frozen cadaveric legs, a tibiotalocalcaneal arthrodesis was performed with use of a blade-plate and a 6.5-mm sagittal screw in one leg and with use of an intramedullary rod in the contralateral leg. After an initial load-deformation curve was obtained, each specimen was loaded to 270 N through 250,000 cycles at a rate of 3 Hz.


RESULTS
Blade-plate-and-screw fixation resulted in significantly higher mean initial and final stiffness and decreased plastic deformation than did intramedullary rod fixation. In addition, there was an inverse correlation between bone-mineral density and the difference in plastic deformation noted between the specimens of each pair.


CONCLUSIONS
Blade-plate fixation is biomechanically superior to intramedullary fixation for tibiotalocalcaneal arthrodesis.
Chiodo
Christopher P
CP
Department of Orthopaedic Surgery, Union Memorial Hospital, 3333 North Calvert Street, Baltimore, MD 21218, USA.
Acevedo
Jorge I
JI
Sammarco
V James
VJ
Parks
Brent G
BG
Boucher
Henry R
HR
Myerson
Mark S
MS
Schon
Lew C
LC
D000704:Analysis of Variance; D001174:Arthrodesis / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D002102:Cadaver; D002111:Calcaneus / Q000601:surgery; D019245:Compressive Strength; D004868:Equipment Failure; D004869:Equipment Safety; D005260:Female; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D016268:Internal Fixators; D008297:Male; D011336:Probability; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013977:Tibia / Q000601:surgery