Chapter 4, Arm Flashcards
What muscles are primary deforming forces in a fx of the humeral shaft?
Pec major and deltoid. May determine direction of displacement
What structure can be damaged in fx of distal 1/3 of humeral shaft?
Radial nerve. Do a GOOD neuro exam and check that nerve
How are fx of humeral shaft classified?
Just descriptive
How are fx of distal humerus classified?
Descriptive: Uni or bicondylar. T or Y shape.
Is a CT needed for a fx of distal humerus?
YES, required for compete evaluation of fracture/joint
Complications from humeral shaft fx?
Radial nerve palsy, commonly from Holstein-Lewis fx (fx of distal 1/3)
Supracondylar fx are common in what population?
Pediatrics
what are the 2 types of supracondylar fx?
Flexion and Extension. Extension m/c. Occurs when distal portion (radius and ulna) move posteriorly.
malreduction of a supracondylar fx may lead to what?
Cubitus varus
What is a radiographic sign that may be seen to indicate a supracondylar fx?
Fat pad sign/Sail sign. Especially post fat pad
When fixing a distal humerus fx with pins, what must you watch out for?
Ulnar nerve. It may have to be transposed anteriorly
What must be checked as far as neuro after a supracondylar fx?
anterior interosseous nerve, radial n, medial and ulnar nerves
What is the classification for radial head fx?
Mason
What is the most likely part of radial head to be fractured?
Anterolateral portion. It is weakest
Wht is Essex-Loprest fx?
A fracture of radial head w/ disruption of Interosseous Membrane and DRUJ. You get migration of radial head proximally.
What is the terrible triad of the elbow?
Elbox dislocation with fx of coronoid and radial head
What is most common direction of elbow dislocation?
Posterior
What is a divergent elbow dislocation?
When radius and ulna go opposite directions. Ex one ant and one post or one medial and one lateral. Very rare
What is the sublime tubercle?
It is on the medial coronoid process of ulna where the anterior band of the MCL inserts providing restraint against valgus stress
What is the most important restraint to valgus stress in the elbow?
Anterior band of MCL. Rupture usually causes avulsion of coronoid on ulna
What is Osborne’s ligament?
Also known as Arcuate ligament, it is the roof of the cubital tunnel where ulnar n passes at elbow. May get compressed in elbow flexion
What ist he ligament of strutters?
A fibrous band running from an anomalous supracondular process to medial epicondyle. Can compress median nerve
What is the triangle you aim for middle of when doing elbow arthrocentsis?
lateral epicondyle, radial head and olecranon
What is the arcuate ligament of the elbow?
Roof of the cubital tunnel (AKA Osborne’s ligament)
