Elbow Complex Flashcards
What is the carrying angle and why is it formed?
5-20 degrees
Trochlea of the humerus extends further distally than does the capitulum
What is the structure of the elbow?
Compound joint
Stable bony arrangement
What is the flexible ROM at the elbow?
145 degrees
How many joints make up the elbow complex? What are they called?
3
Radio-humeral
Superior radio-ulnar
Humeral-ulnar joint
All surrounded by loose capsule
What makes up the humero-ulnar joint? What plane is it in?
Hinge joint between trochlear notch and trochlea of humerus
Not in ant-post plane and so carrying angle in extension/sup formed
What does the semi lunar joint do?
Prevents lateral movement in humero-ulnar joint
What prevents lateral movement at humero-ulnar joint?
Semi lunar notch ulna
Anatomy of the radiohumeral joint?
Limited ball and socket hinge joint
How is the HOR held in the radial notch?
Annular ligament
Structure of radio ulnar joint?
Covers 80% of radial head
Thicker posteriorly > ant
What does the radio ulnar joint allow?
Together allow supination and pronation
What are the four major ligaments of the elbow?
Ulnar collateral
Radial collateral
Annular
Quadrate
What makes up the ulnar collateral ligament?
Anterior oblique band
Posterior band
Intermediate band
Where is the anterior oblique band?
Anterior medial epicodyle to coronoid process
Ulnar nerve crosses this section
Where is the posterior band of the ulnar collateral ligament?
Posterior medial epicodyle to coracoid process
Where is the intermediate band of the ulnar collateral ligament?
Varies
What does the ulnar collateral ligament do?
Resists abduction force
What levels is the ulnar nerve, where is it in the brachial plexus?
C8-T1
Part of medial cord of the brachial plexus
What is the path if the ulnar nerve?
Descends on the posteromedial aspect of the humerus
Travels through cubital fossa at elbow
Enters the anterior (flexor) compartment of the forearm through the two heads of FCU and runs alongside the ulna
What do the lateral and medial cords of the brachial plexus form?
Median nerve
What cord/s of the brachial plexus form/s the median nerve?
lateral and medial
What is the course of the median nerve?
Enters from axilla at inferior margin of teres major
Passes vertically down and courses with brachial artery on medial side of arm between biceps and brachialis
What forms the radial nerve?
C5, C6, C7, C8, T1.
posterior cord of the brachial plexus
What does the radial nerve supply?
3 heads of triceps
12 muscles in posterior aspect of forearm
What is the course of the radial nerve?
Travels through quadrangular space in axilla around the spiral groove humerus a emerges laterally.
- Pierces latral intermuscular septum/branches and travels between brachialis and brachioradialis
- In distal humerus travels anterior to lateral epicondle.
- Pierces forearm divides into 2 branches
What does the radial nerve divide into?
superficial (brachioradialis)
Deep (pierces supinator
What is the largest unprotected nerve in the body?
Ulnar
What supplies the anterior elbow?
musculocutaneus, median and radial nerves
What supplies the posterior elbow?
ulnar nerve
branch of radial nerve to anconeus
What is the close and loose packed position of the radio-humeral joint?
C- 90 degree flexion + 5 degree supination
L- Extension and supination
What is the close and loose packed position for the ulno-humeral joint?
C- Extension
L- 70 degrees flexion
What is the close and loose packed position for the superior radio ulnar joint?
C - 5 degrees supination
L- 70 degrees flexion + 35 degrees supination
What limits elbow flexion 135-145 degrees?
Anterior muscle bulk
Radial head and coronoid opposition and tension in posterior capsule and triceps
What limits elbow extension?
Olecranon opposition and tautness in Ant Oblique potion of ulna collateral ligament and anterior capsule
- Biceps and brachial musculotendinous structures
What limits pronation 85 degree
annular ligament
What does the annular ligament limit?
Pronation at 85 degrees
What does Anterior muscle bulk
Radial head and coronoid opposition and tension in posterior capsule and triceps
limit?
Flexion 135-145 degrees
What are common causes of lateral elbow pan?
Lateral epicondylalgia
Referred pain
(cervical/ upper Tx/ neuromyofascial)
What are the less common causes of lateral elbow pain?
Syonovitis RHJ
RH bursitis
PIN entrapment (radial tunnel syndrome)
What are causes of lateral elbow pain that are not to be missed?
Osteochondritis Dissecans
- Capitulum
- Radius
What are common causes of medial elbow pain?
Flexor tendinopathy
UCL strain
What are less common causes of medial elbow pain?
UN compression
Avulsion # of me
Aphophysitis
What are cause of medial elbow pain that are not to be missed?
Referred pain
What are the common causes of posterior elbow pain?
Olecranon bursitis
Triceps tendinopathy
Posterior impingement
What are the causes of posterior elbow pain?
Common:
Olecranon bursitis
Triceps tendinopathy
Posterior impingement
Less common:
Gout
Not to be missed:
Olecranon #
What are the less common reasons for posterior elbow pain?
Gout
What are causes of posterior elbow pain that are not to be missed?
Olecranon #
What are the causes of lateral elbow pain?
Common:
Lateral epicondylalgia
Referred pain
(cervical/ upper Tx/ neuromyofascial)
Less Common:
Syonovitis RHJ
RH bursitis
PIN entrapment (radial tunnel syndrome)
Not to be missed:
Osteochondritis Dissecans
- Capitulum
-Radius
What are the acute conditions at the elbow?
Fracture/dislocation
Olecranon bursitis
What are the acute on chronic conditions are the elbow?
Instability - MCL rupture
What are the chronic conditions at the elbow?
Lateral epicondylalgia
Medial epicondylalia
Who is prone to elbow dislocation?
High among 10-30 year olds Sporting injury (cycling, gymnastics, football, wrestling), falls, MVA
What is the most common cause for dislocation?
MVA
How common is elbow dislocation?
Account for 10-25% of all elbow injuries
Most common joint in <10 yr olds
What is prognosis for elbow dislocation?
Due to intrinsic stability, re-dislocation uncommon
Chronic instability may be a problem post dislocation
What are the most and least common elbow dislocations?
posterior- most common
90% of dislocations are either posterior or postero-lateral
postero-medial less common
anterior-rare
What is the MOI for elbow dislocation?
FOOSH
elbow hyperextension
Combination of valgus, supination and ER of forearm during axial loaing.
What is the terrible triad?
dislocation + radial # + coronoid
ALWAYS check
neurovascular observation
What injuries are commonly associated with elbow dislocations and why?
Due to the MOI.
- avulsion of either medial or lateral epicondyle
- coronoid and rdial head fractures
- osteochondral lesions - particularly capitulum
Injuries at other sites including shoulder, distal radius an ulnar styloid fracture
How would a patient present with an elbow dislocation?
Severe pain and supporting arm
Forearm shortened with olecranon and radial head protruding posteriorly
Soft tissue swelling deformity
Potential for damage to the brachial artery, median and ulnar nerves
What is nursemaid’s elbow?
Radioulnar joint injury involving a dislocation, this on seen at the proximal joint is known as a radial head subluxation or nursemaid’s elbow.
How does nursemaids elbow occur?
More often sustained when the forearm is pronated
Dislocation head of the radius from the annular ligament that I often caused by an abrupt yanking of the arm.
What are the symptoms of nursemaid’s elbow?
pain that presents low in the forearm away from the injury site, slight swelling and th inability to supinate the forearm, or turn the hand palm-up.
How can fractures at the elbow be classified?
Stable - most elbow dislocations
- most radial head # (beware coronoid #)
Unstable
Olecranon #
All humeral condylar, transcondylar
supracondylar #
Complex #/dilocations (terrible triad)
What I he most common fracture site at the elbow?
Radial head
What is the MOI for a radial head fracture?
Similar to dislocation i.e FOOSH
What is a fracture to the radial head commonly linked to?
Damage to collateral ligaments
How does a medial epicondyle avulsion occur?
Prior epiphyseal closure rapid strong contraction of the forearm flexors is capable of avulsing in the medial epicondule young adults.
Tenderness in medial epicondyle should arouse suspicion in an adolescent.
What may happen if medial epicondyle avulsion is not detected?
increasing valgus deformity.
What are the causes of olecranon bursitis?
Fall on tip of elbow
Resting elbow on a hard surface
Signs and symptoms of olecranon bursitis.
large swelling/pain/slight limitation o flexion.
Treatment of olecranon bursitis.
Avoid provocative activity/rest/ice/NSAIDs/compression.
Note - can become infected.
Xray to rule out joint conditons.
Can have injection to relieve swelling or bursectomy.
