Clinical - Upper limb Flashcards
Where is the clavicle most commonly fractured?
Between medial third and lateral third
What part of the brachial plexus are at risk from a mid-shaft clavicle fracture?
Trunks and divisions
What lung complication is rare but must be ruled out following clavicle fracture?
Pneumothorax
Which artery and vein are most at risk from clavicular fracture?
Subclavian artery and vein
What will happen to the position of the arm and clavicular fragments in a mid-shaft clavicular fracture?
Medial fragment is elevated by SCM.
Lateral segment drops under weight of upper limb and pulled medially by adductor muscles (pec major, lat doors and teres major)
How would you assess brachial plexus damage using myotomes?
Elbow flexion - C5,6 Elbow extension - C7,8 Forearm supination - C6 Forearm pronation - C7,8 Wrist flexion and extension - C6,7 MCPJ extension - C7,8 Finger abduct - T1
What is the coracoacromial arch and what is its role at the shoulder during FOOSH?
Protective arch formed by the coracoacromial arch, prevents superior displacement of the head of humerus.
What is the function of the subacromial bursa?
Reduce friction of suprapsinatous tendon and acromion.
What anatomical structure is attached the anatomical neck of the humerus?
Articular capsule of the shoulder joint
What is the significance of the anatomical neck in children?
Marks region of epiphyseal growth plate
Which nerve is most likely to be damaged in a mid-shaft humeral fracture?
Radial nerve - runs in radial groove in close proximity to the bone
What will be the effect of radial nerve damage on movement at the elbow?
Flexion will be normal
Mild or no compromised extension as the branch to tricep is given off prior to the radial groove.
What will be the effect of radial nerve damage on the wrist and fingers?
Paralysis of brachioradialis and all extensor muscles of wrist and fingers.
= WRIST DROP wrist and fingers flexed
What shoulder dislocation is the most common, why?
Anterior (anteroinferior)
Inferior aspect of the joint is the weakest and pulled anteriorly due to pull of muscles
What features of the shoulder joint make it prone to dislocation?
Glenoid fossa is shallow
In what position would a patient with an anterior shoulder dislocation hold their arm?
Externally rotated and slightly abducted
Which nerve is at risk of damage from anterior dislocation of the shoulder?
Axillary nerve
What complications may occur after anterior dislocation of the shoulder?
Axilary nerve damage Brachial plexus nerve damage Axillary artery damage Recurrent shoulder dislocation Rotator cuff injury
How would you examine a patient to assess axillary nerve damage following shoulder dislocation?
Test for senstation in regimental badge area
Do not test motor function as may increase damage.
What are 2 common causes of posterior dislocation of the shoulder?
Electric shock
Seizure
In what position would a patient with a posterior shoulder dislocation typically hold their arm?
Arm internally rotated and adducted (cannot be externally rotated)
Flattening and squaring of the shoulder with prominent coracoid process.
What is painful arc and what causes it?
Pain on abduction 60-120 degrees.
Supraspinatus tendonitis, subacromial bursitis.
What are 3 main components of synovial joints?
Articular surfaces lined with hyaline cartilage
Synovial membrane lining the cavity that secretes synovial fluid
Protective capsule surrounding the joint
What tissue within joints are primarily affected in RA and osteoarthritis?
Osteoarthritis - Erosion of articular cartilage
RA - synovial membrane becomes inflamed, causing pain and swelling. Joint erosion may follow.
What effect does ageing have on joints?
- Decreased synovial fluid production
- Thinning of articular cartilage
- Shortening of ligaments and decreased flexibility
- Degenerative changes in load-bearing joints
What 2 movements would be impaired in a patient with a torn supraspinatus tendon?
Cannot initiate shoulder abduction (0-15 degrees)
Compression of the ulnar nerve in the cubital tunnel will lead to parasthesia in which area?
What is the name given to this syndrome?
Ulnar 1.5 digits and dorsal aspects of hand
Cubital tunnel syndrome
What is olecranon bursitis and how does it occur?
Inflammation of bursa between the skin and olecranon process of ulna.
Repeated minor trauma - leaning with elbows on desk for hours
Which artery is at risk if the surgical neck of the humerus is fractured?
Posterior circumflex artery- supplies shoulder joint
Which nerve is at risk during a supracondylar fracture
Median nerve
Which humeral fracture is likely to damage the ulnar nerve?
Medial epicondyle fracture
What is ‘pulled elbow’ or ‘nursemaids elbow’, who is more common in?
Subluxation of the radial head from the annular ligament
More common in children as weaker joints and often pulled upwards
What deformity is associated with a Colles’ fracture?
Dinner fork deformity
Which direction does the distal fragment of the radius move in a Colles’ fracture?
Posteriorly
Which direction does the distal fragment of the radius move in a Smiths’ fracture?
Anteriorly
Where would you palpate tenderness to detect a fractured scaphoid?
Anatomical snuff box
Which part of the scaphoid is vulnerable to avascular necrosis during fracture?
Proximal segment due to distal to proximal blood supply.
Define dermatome.
Area of skin supplied by a single spinal nerve.
Define myotome.
Group of muscles supplied by a single spinal nerve.
What is a boxer’s fracture?
5th metacarpal fracture
Where are herbeden’s nodes found and what do they indicate?
Distal IP joint
Osteoarthritis - bony outgrowths
What canal does the ulnar travel through in the hand?
Guyon’s canal
What id dupuytrens contracture?
Disease which causes thickening of the connective tissue in the palm which can shorten and contract the finger/thumb, causing it to flex.
Why does a patient with carpal tunnel syndrome not describe tingling in his palm?
Palmer branch of medial nerve does not pass through the carpal tunnel
Paralysis of which muscles, supplied by the ulnar nerve, are responsible for the ulnar claw if there is ulnar nerve damage at the wrist?
Lumbricals paralysed these usually flex at MCP and extend at IP joints.
So ulnar claw presents as extension at MCP and flexion at IP joints.
When will ulnar claw be visible?
When trying to extend the hand
What is the ulnar paradox?
If the ulnar nerve is damaged at the elbow, the claw is less pronounced although there is increased damage.
Paralysis of ulnar half of FDP and FCU as well as lumbricals, therefore there is less flexion.
What is tennis elbow?
Lateral epicondylitis - inflammation of extensor tendons
Why can superficial lacerations at the wrist result in loss of sensation in the palm of the hand and NOT the digits?
Palmer cutaneous branch of median nerve lies superficial to the carpal tunnel, so is more vulnerable to damage as it not protected by flexor retinaculum.
How might a patient with carpal tunnel syndrome present?
Tingling in lateral 3.5 fingers
Wasting of thenar eminence
Unable to oppose thumb
Paralysis of thenar muscles
When is the hand of benediction seen?
Asking patients with a median nerve injury to make a fist
Explain why median nerve damage causes the hand of benediction.
FDP and FDS both paralysed - proximal and distal IP joints paralysed.
Lateral 2 lumbricals paralysed - cannot flex MCP joint
What is Hilton’s law?
The nerves supplying the joint capsule also supply the muscles moving the joint and the skin overlying the insertions of these muscles.