Clinical Anatomy of the Upper Limb Flashcards
2 joints of the shoulder girdle?
Glenohumeral (synovial)
Acromioclavicular (fibrous)
Stabilisers of the shoulder?
Capsule
Rotator cuff (pull the humeral head into the glenoid fossa) and other muscles
Labrum (ring of cartilage)
What is painful arc syndrome?
AKA shoulder impingement syndrome
Tendons of the rotator cuff muscles become inflamed (tendonitis) as they pass through the subacromial space (beneath the acromion); so, anything causing narrowing of the space can cause this syndrome
Result is: • Tendonitis • Cuff tears • Subacromial bursitis • Osteophytes from the AC joint
Symptoms of painful arc syndrome?
Pain, weakness and loss of movement at the shoulder
Treatment of painful arc syndrome?
Injection of subacromial space
Describe Bankart lesion
Injury of the anterior, inferior glenoid labrum of the shoulder (commonly detaches), due to anterior shoulder dislocation; a pocket forms at the front of the glenoid that allows the humeral head to dislocate into it
Treatment of Bankart lesion?
If the person has recurrent dislocation, it can be repaired
Injuries assoc. with anterior shoulder dislocation?
Axillary nerve is most common nerve injury; it is stretched at the quadrangular space
Also, there can be compression of the brachial plexus and axillary artery
Which type of shoulder dislocation is most common?
Anterior dislocation
Posterior dislocations account for only 1%
Order of the brachial plexus (mnemonic)?
Roots
Trunks
Divisions
Cords
Terminal branches (peripheral nerves)
Ron Taylor Drinks Cold Beer
What is adhesive capsulitis?
AKA frozen shoulder - unclear cause but the shoulder capsule and connective tissue surrounding the glenohumeral joint becomes inflamed and stiff
Leads to a global loss of ROM (especially external rotation)
Treatment of frozen shoulder?
In the painful phase, the glenohumeral joint can be injected
Describe injury of the coracoclavicular ligaments
If ruptured, with AC joint dislocation or clavicle fracture, displacement can occur
Nerve supply to the anterior compartment?
Musculocutaneous nerve (also supplies sensation to the lateral forearm)
Nerve supply to the posterior compartment?
Radial nerve
Scenarios where the radial nerve can be injured?
Susceptible to injury in humeral shaft fractures; as it supplies the extensors of the upper limb, this can cause wrist drop
Most powerful flexor of the arm?
Brachialis
Most powerful supinator of the wrist?
Biceps femoris
Elbow joints?
Humero-ulnar joint
Radio-capitellar joint (allow supinator and pronation, along with the radioulnar joints)
Common extensor origin of the elbow?
Lateral epicondyle (inflamed in Tennis elbow)
Common flexor origin of the elbow?
Medial epicondyle (Golfer’s elbow)
Complications of a supracondylar fracture of the elbow?
Brachial artery occlusion and median nerve injury (radial and ulnar nerves may also be injured)
Symptoms of s supracondylar fracture of the elbow?
Common in children who fall onto an outstretched hand
Pale hand and no pulse - emergency reduction and checking for a return of the pulse
Joints of the forearm?
Proximal and distal radio-ulnar joints facilitate supination and pronation of the forearm; there are strong ligaments at either end
2 types of fracture dislocations of the forearm?
Monteggia fracture dislocation - fracture of the proximal 1/3rd of the ulna with dislocation of the head of the radius
Galeazzi fracture dislocation - fracture of the radius with dislocation of the distal radio-ulnar joint
Nerve supply to the anterior compartment of the forearm?
Medican nerve, except for the flexor carpus ulnaris and the ulnar half of the flexor digitorum profundus (ulnar nerve)
Nerve supply to the posterior compartment of the forearm?
Radial nerve
General rule for nerve supply to extensors of the upper limb?
Radial nerve supply
Shapes of the various carpal bones?
Scaphoid is kidney-bean shaped
Lunate is roughly spherical
Hamate has a hook
Describe scaphoid fractures
Can lead to avascular necrosis
Many fractures do not appear on the 1st X-ray; so, bring patients back in a few weeks and the X-ray should show resorption of bone
Boundaries of the carpal tunnel?
Carpal bones and the flexor retinaculum (AKA transverse carpal ligament)
Names of the hand digits?
Thumb
Fingers: • Index • Middle • Ring • Pinky
What is the palmar fascia?
AKA palmar aponeurosis, invests the muscles of the palm
What is trigger finger and what causes it?
Catching, snapping or locking of the involved finger flexor tendon, assoc. with dysfunction and pain; when the finger unlocks, it pops back suddenly, as if releasing a trigger on a gun
Disparity in size between the flexor tendon and the surrounding retinacular pulley system, most commonly at the level of the first annular pulley, results in difficulty flexing/extending the finger; can be caused by nodules
Intrinsic muscles of the hand and nerve supply?
Thenar muscles and the lateral 2 lumbricals
- LOAF (lumbricals 1 & 2, Opponens pollicis, Abductor pollicis brevis and Flexor pollicis brevis) - median nerve
- Rest of the intrinsic muscles of the hand are supplied by the ulnar nerve
Muscles allow flexion of the fingers?
Flexor digitorum superficialis allows flexion of the PIPJ and MCPJ
Flexor digitorum profundus allows flexion of the DIPJ
Muscles allowing extension of the fingers?
Central slip extensor tendon allow PIPJ extension
Lateral slip’s extensor tendon coverage allows DIPJ extension
Muscle allowing flexion and extension of the fingers?
Intrinsics (interossei & lumbricals) insert into the lateral bands and contribute to flexion at MCPJ and extension at PIPJ
Describe Boutonniere deformiry
Central slip extensor tendon rupture or attrition causes permanent PIP flexion and DIP extension
Seen in RA
Describe swan neck deformity
PIPK volar plate rupture or attrition causes intrinsic muscle tightness and permanent DIP flexion with PIP hyperextension
Seen in RA
Testing motor function of the median nerve and anterior interosseous branch?
Adductor Pollicis Brevis with examiners hand over the thenar muscles from the first web
If there is a lesion and the patient is asked to make an “OK” sign (Flexor Pollicis Longus and Flexor Digitorum Profundus to the index finger), they will make a triangle sign instead
Testing sensory and motor function of the ulnar nerve?
Sensory - feel the 1st dorsal interosseous
Motor - Froment’s test looks at function of adductor pollicis
Testing function of the radial nerve?
If there is a high lesion, triceps function can be assessed by asking the patient to extend the elbow against resistance
If lesion is above the elbow, check for wrist drop
If lesion is below the elbow, check for a finger or thumb drop
