2. Review of the upper limb Flashcards
What are the bones of the shoulder?
Clavicle
Scapula
Humerus
What are the joints of the shoulder?
Glenohumeral
Sternoclavular
Acromoclavicular
What is the pectoral girdle?
Consists of the clavicle and the scapula
What provides strength to the glenohumeral joint and allows movement?
Muscles provide the strength rather than ligaments
These also allow for wide range of movement e.g. rotator cuff muscles
What is the role of the rotator cuff muscles in movement of the glenohumeral joint?
Rotator cuff muscles are tonically active to pull the head of the humerus into the glenoid cavity to provide stability upon movement
What is the blood supply of the upper limb?
Subclavian artery
Axillary artery
Brachial artery
Profunda brachii artery branch to the posterior compartment of arm and triceps
What are the veins of the upper limb?
Deep veins parallel the arteries
Superficial veins are the cephalic, basilic and median cubital veins
Draw out the brachial plexus
Draw out the brachial plexus
What are the nerve roots of the musculocutaneous nerve?
C5, C6, C7
What are the nerve roots of the median nerve?
C5, C6, C7, C8, T1
What are the nerve roots of the radial nerve?
C5, C6, C7, C8, T1
What are the nerve roots of the axillary nerve?
C5, C6, C7, C8, T1
What are the nerve roots of the ulnar nerve?
C8, T1, occasionally C7
What does the musculocutaneous nerve innervate?
Innervates the anterior compartment of the arm i.e. the biceps
What does the median nerve innervate?
Innervates the anterior compartment of the forearm (passes through the carpal tunnel)
(two exceptions - done by the ulnar)
What does the radial nerve innervate?
Posterior compartment of the arm (triceps) and posterior compartment of forearm (extension of digits)
What does the axillary nerve innervate?
Deltoids
Teres minor
Axilla
What does the ulnar nerve innervate?
Flexor carpi ulnaris and flexor digitorum profundus (the two exceptions from the anterior compartment of the arm)
Also the muscles of the little finger
Are the nerves of the brachial plexus sensory or motor?
They are mixed motor and sensory
What are the two main clinical conditions that can occur at the shoulder?
Break/fracture of the clavicle
Dislocated shoulder
How does a break/fracture of the clavicle occur?
Can occur by direct or indirect force
Direct - something falls onto the shoulder or hits the front of the pectoral girdle
Indirect - person falls forwards and puts their hands out to catch their fall - force travels up the upper limb to the shoulder
What is the clinical significance of a fracture to the clavicle?
All of the arteries to the upper limb pass under the clavicle and so a fracture can result in an obstruction of the blood flow
If there is a lack of sensation of the arm or an absence of pulses - the blood supply is being cut off and this is a medical emergency
How will a fracture to the clavicle present?
Shoulder droops down
Reduced width of shoulder
The shoulder of the broken clavicle will drop due to gravity pulling down on the limb (generally)
Should notice a reduced width of the shoulder in which the clavicle is fractured
What is the clinical significance of a dislocated shoulder?
Dislocation of the glenohumeral joint is the most common
Reoccurence rate from minor trauma is very very high e.g. sleeping funny can dislocate it again
How will a dislocated shoulder present?
Lose the rounded profile of the shoulder
Square appearance of the shoulder
The acromion becomes more prominent and visible
What are the two main clinical conditions that can occur at the shoulder?
Break/fracture of the clavicle
Dislocated shoulder
How does a break/fracture of the clavicle occur?
Can occur by direct or indirect force
Direct - something falls onto the shoulder or hits the front of the pectoral girdle
Indirect - person falls forwards and puts their hands out to catch their fall - force travels up the upper limb to the shoulder
What is the clinical significance of a fracture to the clavicle?
All of the arteries to the upper limb pass under the clavicle and so a fracture can result in an obstruction of the blood flow
If there is a lack of sensation of the arm or an absence of pulses - the blood supply is being cut off and this is a medical emergency
How will a fracture to the clavicle present?
The shoulder of the broken clavicle will drop due to gravity pulling down on the limb (generally - some may hold their shoulder up)
Should notice a reduced width of the shoulder in which the clavicle is fractured
What is the most common joint to dislocate?
Dislocation of the glenohumeral joint is the most common
How will a dislocated shoulder present?
Lose the rounded profile of the shoulder
The weight of the arm will pull the humerus, forearm and hand inferiorly - all dragged down
Stretching of the deltoid muscle - square appearance of the shoulder
Acromium becomes more visible - usually hidden by the deltoid
What is important about the reoccurrence rate of a glenohumeral dislocation?
Reoccurrence rate from minor trauma is very very high e.g. sleeping funny can dislocate it again
What nerve is at greatest risk of damage from a glenohumeral fracture and why?
Axillary nerve
Runs just underneath the GH joint
What is the recurrence of a glenohumeral dislocation?
50-89%
What is the most common direction of a glenohumeral dislocation and why?
Anterior dislocation because the posterior aspect is protected by three rotator cuff muscles (supra, infra and teres minor at a common tendon insertion) and the scapula and the acromium
BUT the posterior aspect is only protected by the subscapularis muscle
What does the axillary nerve innervate and what is the function?
Deltoid muscle
Abduction of the arm
What will damage to the axillary nerve result in?
Paralysis of the deltoid muscle - weak abduction of the arm
Loss of sensation in a small area of skin covering the central region of the deltoid
How can damage to the deltoid be treated?
Replace the deltoid with the pectoralis major - has a different nerve supply so can be used instead
What nerve is responsible for winging of the scapula?
Winging of the scapula indicates damage to the long thoracic nerve
What does the long thoracic nerve innervate?
The serratus anterior muscle
Where does the long thoracic nerve come from?
Comes from the brachial nerve
What does damage to the long thoracic nerve result in?
Loss of serratus anterior movement - do not have the full range of movement of the scapula - only have the trapezius
Winging of the scapula presentation
What does the thoracodorsal nerve innervate?
Latissimus dorsi
Which nerves can be damaged in an axillary node clearance and which of these is the most important?
Long thoracic nerve
Thoracodorsal nerve
Most important to not damage the long thoracic nerve
What is the trapezius muscle innervated by?
Spinal accessory nerve - cranial nerve
What does damage to the spinal accessory nerve result in?
How will this present?
Spinal accessory innervates the trapezius muscle
Damage leads to drop of shoulder (trap acts to keep the shoulder elevated from gravity)
Presents as a much milder form of winging of the scapula
What are the joints at the elbow?
Humeroulnar joint
Humeroradial joint
Proximal radioulnar joint
What are the compartments of the arm?
Anterior and posterior
What are the arteries and nerves in the anterior compartment of the arm?
Brachial artery
Median, musculocutaneous and ulnar nerves
What are the arteries and nerves in the posterior compartment of the arm?
Profunda brachiii artery (deep artery of the arm)
Radial nerve
What nerve is at risk from a midshaft humeral fracture and how will this present?
Radial nerve
Wrist drop
Which nerve is at risk from a supracondylar fracture and how will this present?
Median nerve
Hand of Bennidiction
What is the serratus anterior muscle innervated by?
Long thoracic nerve
What is the latissimus dorsi muscle innervated by?
Thoracodorsal nerves
What nerve is at the medial epicondyle?
Ulnar nerve
What are the different compartments of the forearm?
Anterior
Posterior
What is found the anterior compartment of the forearm?
Flexors of the hand Pronators Median nerve - carpal tunnel Ulnar nerve Radial artery Ulnar artery
What is found in the posterior compartment of the forearm?
Extensors of the hand
Supinators
Radial nerve
Posterior interosseus artery
Where does the posterior interosseus artery come from?
This is a branch from the ulnar artery
What is Colles’ fracture?
Fracture of the wrist - fracture of the distal radius within 2cm of the most distal end
What is a Colles’ like fracture?
If the fracture involves the ulnar too
What nerve innervates the thenar muscle group?
Median nerve through the carpal tunnel
What is the group of muscles that moves the middle finger called?
The hypothenar muscles
What are the three nerve terminations of the hand?
Median nerve
Radial nerve
Ulnar nerve
Superficial veins of the arm - which is medial and which is lateral?
Cephalic - lateral
Basilic - medial
Vein joining the cephalic and basilic veins is?
Median cubital vein
Square appearance of the shoulder - fracture clavicle or shoulder dislocation?
Shoulder dislocation
Acromion more visible at the shoulder - fractured clavicle or shoulder dislocation?
Shoulder dislocation
Which looks visibly more severe - fracture clavicle or shoulder dislocation?
Shoulder dislocation
Which nerve is at risk of injury from shoulder dislocation?
Axillary nerve
Fracture of clavicle/shoulder dislocation - which is a medical emergency and why?
Fractured clavicle
Loss of all peripheral pulses can occur
Damage to the deltoid muscle - the deltoid can be replaced with which muscle?
Pectoralis major
Anterior or posterior dislocation of shoulder more common?
Anterior
Damage to the spinal accessory nerve presents as?
Loss of function of trapezius - drooping shoulder
Dislocation of the elbow can damage which artery and which nerve?
Ulnar artery and ulnar nerve
Radial head fits into which ligament?
Anular ligament
Anular ligament also referred to as?
Anular ligament of the radial head
Colles’ fracture has what presentation?
Dinner fork deformity
Why is subluxation of the radial head common in children?
Radial head is much larger than the anular ligament into which it fits at this age
Colles’ fracture will only be visible on what x-ray view?
Lateral (rather than AP)
‘Dorsal’ displacement means anterior or posterior displacement?
Posterior
Why might a scaphoid fracture go undiagnosed and why should you wait 7-10 days to x-ray again?
The healing of the fracture is what is visible on the x-ray and this will not be apparent until 7-10 days later
