Internal fixation: pins, wires and interlocking nails Flashcards
When is internal fixation warranted?
when external coaptation can’t be use or has distinct disadvantages
What bones should internal fixation always be used?
humerus and femur
What kind of fractures should usually be fixed by internal fixation?
- oblique
2. comminuted
What do intramedullar pins control?
bending. but need help for controlling others
What do interlocking nails, external skeletal fixators and bone plates control?
all the forces that act on the fracture if the correct hardware/configuration is used
What is internal fixation?
fracture repair by means of hardware that attaches directly to the bone
What are fractures for which internal fixation is much better than external coaptation?
- open fractures
- fractures of femur, humerus, pelvis
- articular fractures–perfect reduction–early joint movement
- oblique or comminuted fractures–control commpresion
- fractures in which primary force acting is tension–olecranon, calcaneus, greater trochanter
What forces to intramedullar pins control?
bending
What is an intramedullary pin
a rod that stabilizes broken bone by passing longitudinally within medullary canal, v/ close to neutral axis
what is a K-wire
A small pin
What are 4 advantages of intramedullary pins
- availability
- axial alignment
- bending control
- minimal to moderate blood supply disruption
What are 4 advantages of intramedullary pins
- availability
- axial alignment
- bending control
- minimal to moderate blood supply disruption
What are 4 disadvantages of intramedullary pins?
- pins control only bending
- can’t always anatomically repair comminuted fractures
- potential for injury to surrounding structures–sciatic nerve
- not good for skull, pelvis. RADIUS
What are two ways to place an IM pin
- normograde placement-
2. retrograde placement
What is normograde placement?
reduction of fracture then pin run down middle–for tibia, often ulna, humerus