CONDITIONS OF THE ELBOW Flashcards
Describe supracondylar fractures of the distal humerus
-Comprise up to 75% of all elbow injuries
-90% of supracondylar fractures seen in children younger than 10 years of age.
-Peak age 5-7 years. (occuring more commonly in boys)
What is the MOI of supracondylar fractures of the distal humerus?
-Common mechanism= falling from a moderate height onto to outsretched hand with elbow hyperextended.
e.g. fallling of ‘monkey bars’
-Less common mechanism= falling onto a flexed elbow (more common in elderly)
Presentation of supracondylar fractures of the distal humerus?
-Child present with:
>Pain, Deformity , Loss of function
Desribe appearance of fracture in supracondylar fractures of the distal humerus
-Fracture line is usually extraarticular (i.e. joint is not involved) and the distal fragment is usually displaced posteriorly.
What are 3 main complications of supracondylar fractures of the distal humerus?
- Malunion resulting in cubitus varus known as gunstock deformity (resembles stock of gun).
- Damage to the median nerve (most common), radial nerve, ulnar nerve.
- Ischaemic contracture, damage to the brachial artery, can lead to compartment syndrome and then Volkman’s ischaemic contracture.
Descibe appearance of arm in Ischaemic volkman’s contracture.
-Wrist is typically flexed, MCPJ extended, flexion at IPJ, forearm is pronated, elbow is flexed.
Describe MOI elbow dislocations (general)
-Occur when a person fall on their outstetched hand with the elbow partially flexed.
What are the features of posterior elbow dislocations?
(named by displacement of distal fragment)
-90% of elbow dislocations
-distal end of humerus dirven through the joint capsule anteriorly
-ulnar collateral ligament is usually torn, ulnar nerve may damaged
What are the features of anterior elbow dislocations?
-<10% of elbow dislocations
-Usually caused by direct blow to the posterior apsect of the flexed elbow
-associated with fracture of olecranon (due to degree of force required to dislocate joint)
What is Pulled elbow ‘nursemaids elbow’
-Subluxation of the radial head
-Most commonly occurs in children aged 2-5 years
What is the presentation of pulled elbow?
-Reduced movement of the elbow
-Pain over the lateral aspect of the proximal forearm
-Described as ‘not using their arm’ (by parents)
What is the MOI of pulled elbow?
-Longitudional traction applied to the arm with forearm pronated
e.g. tugging an uncooperative child or swinging child by the arms.
Why does injury occur most commonly in pronation?
-In pronation, the annular ligament is lax
(taut in supination)
-easier for subluxation to occur
What is MOI radial head and neck fractures?
-Commonest type of elbow fracture in adults
-Result from FOOSH when radial head impacts on the capitellum of the humerus.
Presentation of radial head and neck fractures?
-Pain in the lateral aspect of their proximal forearm
-Loss of range of movement
-Swelling is usually modest in comparison with e.g. supraconcylar fractures
What are the X-ray signs in radial head and neck fractures?
-Fat pad sign/sail sign: indicates presence of effusion.
-likely due to trauma, haemoarthrosis secondary to intra-articular fracture.
-displacement of the fat pad is relatively radio-leucent so appears black on X-ray
Describe OA of the elbow?
-Relatively uncommon (due to well matched joint surfaces and strong stabilising ligaments
-Elbow can tolerate large forces without becoming unstable so less wear and tear with age.
Presentation of OA of the elbow?
-Grating sensation (crepitus)
-Locking of the elbow (caused by loose fragments of cartilage)
-Swelling due to effusion (relatively late)
-LOSS (radiological signs)
What are some complciations of OA of the elbow?
-Osteophytes can impinge on ulnar nerve causing paraesthesia, muscle weakness.
-Stiffness of the elbow (tolerated by patients)
Describe RA of the elbow?
-Autoantibodies known as rheumatoid factor attack the synovial membrane.
-Inflammed synovial cells proliferative to form a pannus whihc leads to joint erosion + derformity.
What are the Xray features of RA (elbow)
-Joint space narrowing
-Periarticualr osteopenia
-Juxtaarticular bony erosions
-Subluxation + gross deformity
Describe management of RA
-Managed medically rather than surgically through prescription of disease-modifying medication.
-Surgery in severe cases to releive pain + improve mobility (total elbow replacement)
What is lateral elbow tendinopathy (‘tennis elbow’)?
-called lateral epicondylitis
-chronic overuse disorders in tendons
-Pain at the site of common extensor tendon at the lateral epicondyle.
What is the MOI of tennis elbow?
-Extensor carpi radialis brevis (ECRB) weakened from overuse, microscopic tears form in the tendon.
-Leads to inflammation and pain.
