41/42: External Fixation Rings - Smith Flashcards Preview

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Flashcards in 41/42: External Fixation Rings - Smith Deck (12)
1

acute trauma indications for ring ex fix

  • Tibial articular fractures (pilon, plateau)
  • Tibial articular fractures with diaphyseal extension
  • High energy diaphyseal fractures of tibia
  • Calcaneal fractures
  • Ankle fractures
  • Also limb reconstruction (correction of post-traumatic, acquired and congenital deformities that are multiplanar)

2

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stability is created by ...

rigidity is created by ...

  • Stability created with tensioned wires inserted into bone
  • Rigidity created with half pins screwed into bone

3

what is a hybrid fixator?

combination of unilateral and circular fixators

Stability created with tensioned wired attached to circular frame

Rigidity created with half pins attached to circular frame and unilateral frame

*****

4

describe properties of transosseous wires

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  • Transosseous wires are placed under tension and undergo a self-stiffening effect
  • Increased stability in the bone-fixator interface
  • Optimal stabilizing position is 90 degrees to each other
    • Smaller angles maybe used, but have to increase wires

5

transosseous wire care

- daily cleaning with alcohol or peroxide

- betadine avoided

- antibiotic ointment applied

6

dynamization

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  • removal of circular fixator
  • release some of tension from the wires over time
  • allows the bone to strengthen with an increase in WB force
  • decreases potential for fx
  • short leg cast with partial WB if dynamization is not possible

7

minor complications for ex fix

  • edema
  • pin tract irritation
  • pin tract infection (dif from irritation with cultures)
  • fractured transosseous wires
  • pain secondary to positioning of the wires

8

why is edema a complication for ex fix?

  • ex fix does not allow postop wound compression
  • can lead to hematoma, compartment syndrome, serous and hemorrhagic fluid around wires

9

major complications ex fix

  • nonunion
  • osteomyelitis
  • neurovascualr injury
  • joint subluxation
  • fracture

10

factors contribution to nonunion

- poor fixation construction (not enough wires to produce stiffness)

- distraction too quickly

- infection, smoking

11

prevent joint subluxation

fixation distal to distracted joints

12

technique to decrease neurovascular injury

damage occurs by twisting structures around wire during drilling

- decrease by drilling wire through cortices and ushing through skin

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