Screws And Plates Flashcards
What are the 3 applications of bone screws?
Lag screw -interfragmentary compression
Position screw
Plate screw
What are the types of bone screws?
Cancellous Cortical Shaft Cannulated Locking head Self tapping
How is a lag scre palced?
Holes are drilled equidetant from fracture edges at a right angle to fracture plane
A smaller hole is drilled in far cortex (core diameter of screw)
A larger hole is drilled in near cortex (diameter of the screw threads)
What type of screws can be used for lag screw application?
Fully or partially threaded
What is the main purpose of lag screws ?
Interfragmentary compression
When is a position screw indicated?
When placement of a lag screw will cause fragment to collapse
How is a position screw placed?
Same diameter hold is drilled in near and far cortex, the drill hole is measured and tapped
T/F: bone plates resist all forces
True
What are the types of bone plates?
Dynamic compression plate DCP
Limited contact dynamic compression plate LC-DCP
Locking compression plate LCP
What type fo plate has deep notches between the holes that allows for contouring in an additional plane
Reconstruction plates
What type of plate can be cut to any length, is versatile, but relatively weak?
Veterinary cuttable plate
What type of plate provides compression to the acetabulum?
Acetabular plates
Can be contoured — referral procedure
What type of plate has limited contact with the bone, can contour in almost any direction and can be used for neutralization or bridging of fractures
String of pearls
A bone plate should always be placed on the ________ side of the bone
Tension
Bone plate should be placed on the ______ side of the femur
Lateral
Bone plate should be placed on the _____ side of the tibia
Medial
Bone plate should be placed on the _______ side of the radius
Caudal
Bone plates are placed on the ________ side of the proximal humerus, but on the _________ side in the distal humerus
Cranial/lateral; medial
When plating a fracture, you should engage at least _____ corticosteroids on each side of the fracture line
6
Screws for a bone plate should be at least ______mm from a fracture line
5
Also avoid plate holes over the fracture line
Avoid cordial defects
T/F: dynamic compression plates can be used as a compression, neutralization or bridging plate
True
Compression plates are applied using the _________________ principle to allow compression of a transverse fracture
Spherical gliding
— eccentrically loaded screw
What type of plate is used in an oblique or comminuted fracture?
Neutralization plate
Reduced anatomically with lag screws or cerclage wires
Plate protects interfragmentary compression from rotation, bending, or shearing
T/F: there is no load sharing when placing a bridging plate
True
Plate carries the entire load
What type of plate could you use if you are concerned about blood supply to the fracture site, that would allow for improved cortical perfusion?
Limited contact dynamic compression plate (LC-DCP)
What is minimally invasive plate osteosynthesis?
Placement of a plate epiperisoteally through keyhole incisions
Uses locking plate and screws
Fluoroscopy used
What do you call the fixation method that uses a stainless steel nail placed within the medullary cavity that is locked into the bone by screws that cross the bone and pass through holes in the nail?
Interlocking nail
T/F: interlocking nail placement can only be done normograde
True
When can interlocking nail fixations be used?
For mid diaphyseal fractures of numerous, femur and tibia
NOT radius
