Is cannulated-screw fixation an alternative to plate osteosynthesis in open book fractures? A biomechanical analysis.
The current biomechanical work compares the symphyseal and sacroiliac stability obtained with two systems of bone osteosynthesis. The two methods of fixation compared were the 6-hole suprapubic non-locked plate and pubic fixation with two cannulated screws, a novel technique that can be applied percutaneously in the clinical practice. The aim of this study was to examine the validity of the use of two-cannulated-screws osteosynthesis in order to minimize the secondary effects of open fixation, especially in patients in whom an open reduction is contraindicated.



A biomechanical study was designed in 9 fresh, human pelvis specimens, simulating an AO B1.1 type injury, using both fixation systems sequentially in each specimen. In both parts of the test, the specimens were subjected to an axial load of 300N. Displacements and rotations between the different pelvic elements were studied by means of a discrete set of points. The absence of differences between the two systems has been set as the null hypothesis.



There were significant differences in favor of the cross-cannulated screws in most of the displacements measured at the pubic symphysis and sacroiliac joint.



Fixation of the AO B1.1 type fractures with cross cannulated screws restores the biomechanical behavior of the pubic symphysis, obtaining better stability than fixation with the 6-hole non-locked plate. To date, no comparative, biomechanical studies have been conducted with these two systems of osteosynthesis. This study demonstrates that cross-cannulated screws fixation of the pubic symphysis in AO B1.1 pelvic fractures should be considered as an alternative to the conventional plating system.
Clinical Orthopedics, Trauma Surgery and Rheumatology Management Unit, Virgen del Rocío University Hospital, Seville, Spain.
Ángel
A
Lázaro Gonzálvez
Department of Mechanical Engineering, University of Seville, Escuela Superior de Ingeniería, Seville, Spain.
Javier
J
Martínez Reina
Clinical Orthopedics, Trauma Surgery and Rheumatology Management Unit, Virgen del Rocío University Hospital, Seville, Spain.
Pedro
P
Cano Luis
Orthopedic Surgery Department, Puerto Real University Hospital, Cádiz, Spain. Electronic address: jjimenezbaquero@gmail.com.
Juan
J
Jiménez Baquero
Orthopedic Surgery Department, Puerto Real University Hospital, Cádiz, Spain.
José
J
Sueiro Fernández
Clinical Orthopedics, Trauma Surgery and Rheumatology Management Unit, Virgen del Rocío University Hospital, Seville, Spain.
Miguel Ángel
MA
Giráldez Sánchez
D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D002102:Cadaver; D004867:Equipment Design; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D008875:Middle Aged; D010384:Pelvic Bones / Q000473:pathology*; D013314:Stress, Mechanical
Biomechanics; Cannulated screw; Minimally invasive fixation; Open-book fracture