Lecture 17 Flashcards
How would you get a supracondylar fracture?
- FOOSH (90% young children-usually boys)
- falling onto a flexed elbow (5% elderly)
What does a patient present with in a supracondylar fracture?
- pain
- deformity
- loss of function
What is the fracture line described as in a supracondylar fracture?
Extra-articular
-joint is not involved
Distal fragment usually displaced posteriorly
What are the 3 main complications with a supracondylar fracture?
- malunion, resulting in cubitus varus (gunshot deformity)
- damage to median (most common), radial or ulnar nerve
- ischaemic contracture: brachial artery passes very close to fracture site so may be damaged/occluded by displaced fracture. If reflex spasm of collateral circulation around elbow occurs, there will be ischaemia as it impedes arterial flow. Untreated= muscle infarction
What is Volkmann’s contracture?
During repair phase of infarcted muscle due to ischaemiua resulting from supracondylar fracture, the dead muscle tissue is replaced by scar tissue via fibrosis. Fibrotic tissue contracts (myofibroblast activity) and results in a flexion contracture
- wrist is flexed
- metacarpophalangeal joints extended
- interphalangeal joints flexed
- forearm pronated
- elbow flexed
Why is it important a neurovascular exam is conducted in a patient with a supracondylar fracture?
- median/ulnar/radial nerve may be damaged
- brachial artery damage/reflex spasm of the collateral circulation
How does an elbow dislocation occur?
-FOOSH (child) with elbow partially flexed
Configuration of bones contributes to stability of joint of elbow in full extension and flexion, whereas stability of joint in mid-flexion is more reliant on the ligaments making dislocation more likely to occur here
-considerable forces is required, sporting injuries are common
What are the top two most comon joints to dislocate?
-Elbow
-shoulder
Due to high frequency of FOOSH’s
What is the most common form of elbow dislocation?
Posterior (named by movement of distal fragment)
- distal end of humerus is driven through joint capsule anteriorly
- ulnar collateral ligament is usually torn
- associated fracture
- ulnar nerve damage
How would you obtain an anterior dislocation of the elbow?
Direct blow to posterior aspect of the flexed elbow
-associated fractures commonly seen due to degree of force required to dislocate the joint
What is a pulled elbow? (nursemaids elbow)
Subluxation (incomplete dislocation) of the radial head
What do patients present with in a pulled elbow?
- reduced movement at elbow
- pain over lateral aspect of proximal forearm
- parents state child is not using their arm
In which age group is a pulled elbow most common and how would you obtain it?
2-5 years old
-longitudinal traction applied to arm with forearm pronated
Why does a pulled elbow more commonly occur in pronation of the forearm?
In pronation the annular ligament is relaxed, whereas in supination it is taut
-therefore it is easier for subluxation to occur
Longitudinal traction tearsthe distal attachment of annular ligament where it is loosely attached to radial neck. Radial head is then displaced distally through torn ligament
Why is pulled elbow less common the older you get?
The annular ligament strengthens as you age
What is the most common elbow fracture in adults?
Radial head/neck fractures
What do radial head/neck fractures result from?
FOOSH, when radial head impacts the capitellum of the humerus
What does the patient present with in a radial neck/head fracture?
- pain in lateral aspect of proximal forearm
- loss of range of movement
- swelling is modest in comparison to supracondylar fractures
What does an X Ray show for a radial neck/head fracture?
Fat pad sign (sail sign): indicates an effusion (accumulation of fluid) is present, likely due to haemarthrosis (blood in joint) secondary to intra-articular fracture in the setting of trauma
- sail shape caused by displacement of anterior fat pad
- displaced fat pad appears black on XRay
- some patients have a posterior fat pad sign due to displacement of the cresent of fat located usually within the olecranon fossa
Why is osteoarthritis of the shoulder uncommon?
-well matched joint surfaces
-strong stabilising ligaments
Therefore elbow can tolerate large forces without becoming unstable, so less ‘wear and tear’ with age
In whom is OA of the elbow most common?
Men
-manual workers
-athletes who engage in throwing
(can be primary or secondary)
What does the patient present with for OA of the elbow?
- creptius (grating)
- locking (caused by loose fragments of cartilage)
- swelling due to effusion
- osteophytes can impinge on ulnar nerve causing paraesthesia and muscle weakness
- stiffness of elbow
- loss of extension is tolerated well by patients as results in little limitation to their daily activities
What is RA?
Autoimmune disease where autoantibodies (rheumatoid factor) attack synovial membrane. Inflamed synovial cells proliferate to form a pannus which penetrates through cartilage and adjacent bone, leading to joint erosion adn deformity
What does RA usually affect?
-metacarpophalangeal joints
-proximal interphalangeal joints
-feet
-cervical spine
-large joints
Also leads to damage of organs: eyes, skin, lungs, heart, blood vessels, kidneys
-patients with RA often have anaemia of chronic disease
