Elbow Flashcards
Suparcondylar fracture of the dsital humerus mechaism
falling form height onto outstreached arm with elbow hyperextended
most common age people get supracondylar fractures
children
what is a less common mechaism of obtaining a supracondylar fracture of the distal hymerus
falling onto a flexed elbow - seen in elderly
in supracondylar fractures the distal fragment is usually displaced anteriorly or posteriorly
Posteriorly
3 main complications with supracondylar fracture
Malunion
Nerve Damage
Volkmann’s ischaemic contracure
malunion of the distal humerus results in
Cubitus Varus - gunstick defomity
Which nerves can be damnaged in a supracondylar fracture
Median nerve is most common, radial nerve and ulnar nerve
Volksmann’s ischamic contracture
Brachial artery damanged
ischemia of muscles in anterior compartment of forearm
odema
increase in compartment pressure (conpartment syndrome) - making ischemia worse
during repair dead muscle replaced by scar tissue through fibrosis
sibrotic tissue contracts - resulting in flexion contracture
Volksmann’s ischamic contracture the fingers are extended at what joint
metacarpophlngeal joint
treatment is volksmann’s ischamia
emeregency reduction and fixation of the fracture
Mechaism of elbow dislocation
fall on outstretched arm slightly flexed
why id elbow dsilaction more likely to occur mis flexion and extention
as stablilty of the elbow is more reliant on ligament during this period
90% of elbow dislocation’s are ..
remember elbow disolactions are named as the distal fragment e.g the radius and the ulnar
posterior
i.e the distl end of the humerus is driven through the joint capsule anteriorly
common ligament to tear in elbow dislocation
ulnar collateral ligament
Anterior dislocation’s (10%) mechanism
direct blow to the posterior aspect of a flexed elbow
associated fractures scenes with anterior dislocation and why?
Fracture of the olecranon
due to the degree of force required to dislocate the joint
Pulled elbow (nursemaids elbow)
Subluxation of the radial head
subluxation = partical disruption of a joint with some remaining but abnormal apposition of the articular surface
Children aged 2-5 present with pulled elbow how do they present
reduced movement of elbow
pain over the lateral aspect of proximal forearm
common mechanism of pulled elbow
longitudinal traction is applied to the arm with forearm pronated
(tugging an uncoopertive child or swinging a child by their arms during play)
why does pulled elbow occur in pronation
annular ligament is relaxed in pronation - easier for sublaxion to occur
pulled elbow how it occures
longitudinal traction on the radial head tears the distal attachment of annular ligament from radius.
radial head is then displaced dsially through the torn ligament
radial head and neck fractures mechaniim of injury
fall on a outstrahced hand when the raidal head impacts the capitellum of the humerus