a) An iliosacral screw into the S1 vertebral body
b) Iliosacral screws in S1 and S2
c) Tension band plate fixation
d) Triangular osteosynthesis
e) An iliosacral screw that traverses the S1 vertebral body and achieves purchase in the opposite iliac wing
2. The injury centre of rotation in a flexion-distraction fracture:
a) is located anterior to the centre of rotation of the spine
b) is located within the centre of rotation of the spine
c) is located posterior to the centre of rotation of the spine
d) may be located in all three of the above.
3. Which one of the following traumatic spinal fractures places the neurologic structures at greatest risk?
a) compression fracture
b) translational fracture
c) flexion-distraction fracture
d) extension-distraction fracture
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Answers
1.
Answer: d
Explanation: The term triangular osteosynthesis describes fixation constructs that involve placement of pedicle screws in the lower lumbar and the posterior ilium in conjunction with iliosacral screws. In a biomechanical study, triangular osteosynthesis was shown to be superior to iliosacral screws alone for fixation of unstable transforaminal sacral fractures.
2.
Answer: a
3.
Answer: b
