Upper limb prosection book Flashcards
What muscles are involved in forward flexion of shoulder?
Anterior fibres of deltoid
Describe important features of scapula
-Supraspinous fossa
-Infraspinous fossa
-Coracoid process
-Acromion
-Spine of scapula
Describe ‘painful arc’
-Usually inflammation supraspinatous tendon
-Due to degeneration/trauma
-Painful abduction arm between 60-120 degrees
What is the brachial plexus?
-Network of nerves that originates in neck and extends into axilla
-Gives rise to most of nerves that supply upper limb
What are the 5 regions of the brachial plexus?
Roots
Trunks
Divisions
Cords
Branches
Describe the origins of the brachial plexus
Originates from ventral rami c5-T1
How many branches are there from divisions of brachial plexus?
None: all branches exit brachial plexus before or after the divisions
How many branches from roots of brachial plexus?
3:
-Dorsal scapular nerve from C5
-Nerve to subclavius from c5 and c6
-Long thoracic nerve c5-c7
What is the nerve roots of long thoracic nerve?
Long thoracic nerve of bell
C5,6,7 bells in heaven
How many branches from trunks of brachial plexus? Where are they from?
1
-suprascapular nerve (upper trunk)
Draw a line diagram of brachial plexus and label branches
label branches
Name salient parts of humerus
Greater tubercle
Lesser tubercle
Intertubercular (bicipital) groove
Medial epicondyle
Trochlea (medial: we like trotsky more than stalin)
Capitulum
Name muscles attaching to humerus
Pec major
LD
Teres major
Deltoid (deltoid tuberosity)
How would you localise humerus as left or right?
With humeral head pointing inwards, capitulum and trochlea point forwards
What are the boundaries of the axilla?
Apex: cervicoaxillary canal (convergence of clavicle, scapular, first rib)
Anterior: pec major and minor
Base: axillary fascia
Posterior: subscapularis, teres major, lat dorsi (superior to inferior)
Medial: thoracic wall and serratus anterior
Lateral: intertubercular groove of humerus
What are contents of axilla?
-Axillary artery and branches
-Axillary vein
-Axillary lymph nodes
–> 1: below pec minor
–> 2: behind pec minor
–> 3: above pec minor
-Brachial plexus: cords and branches
-Fat
Structures that pierce clavipectoral fascia
Two in:
-Cephalic vein
-Lymphatic vessels
Two out:
-Thoraco-acromial trunk
-Lateral pectoral nerve
What is the clavipectoral fascia?
Thin layer fibrous tissue surrounding pec minor
-Superiorly attaches to clavicle and inferiorly to axillary fascia
What nerves could be damaged with humeral fracture?
-Axillary nerve as it passes close to neck of humerus in quadrangular space
-Radial nerve as it winds around shaft of humerus at junction between proximal 2/3rds and distal 1/3rd
-Ulnar nerve as it passes behind medial epicondyle
-Median nerve in supracondylar fracture
What structures make up roof of cubital fossa?
Bicipital aponeurosis, deep fascia of forearm, subcut tissue, skin
Where does the median cubital vein lie relative to bicipital aponeurosis?
Superficial to it
Describe the anatomy of the cubital tunnel
-Roof: aponeurotic expansion of two heads flexor carpi ulnaris
-Spans from medial epicondyle of humerus to olecranon process of ulna
-Floor: medial collateral ligament of elbow
-medial border of olecranon process to medial epicondyle
What is clinical significance of cubital tunnel?
-Ulnar nerve passes through cubital tunnel as it runs behind medial epicondyle
-Ulnar nerve can be compressed within cubital tunnel
-This results in ulnar nerve symptoms and signs within forearm and hand and is termed cubital tunnel syndrome
What happens to tendons FDS and FDP?
-FDS tendon splits to insert into middle phalanges
-FDP tendon passes through this split in FDS to insert into base of distal phalanx
What prevents tendons from bowstringing?
-Series of fascia coverings that anchor tendon to bony skeleton, while allowing tendons to glide smoothly
-At wrist: flexor retinaculum
-On fingers: annular (A1-5) and cruciate (C1-3) pulleys
Describe flexor arrangement of pulleys:
A1: over MCP joint
A3: over PIPJ
A5: over DIPJ
A2: over proximal phalanx (most important pulley)
A4: pulley is over middle phalanx (second most important pulley)
C1: between A2 and A3
C2: between A3 and A4
C3: between A4 and A5
Proximal to distal: A1, A2, C1, A3, C2, A4, C3, A5
Where does FDS and FDP insert?
FDP: base of distal phalanx
FDS: Inserts into base of middle phalanx
How do you test FDS and FDP?
FDP: flexion of DIPJ
FDS: flexion of PIPJ with other fingers restrained
What is the clinical significance of palmaris longus’s abscence in 10% of population?
Can be used as tendon graft.
How many compartments are there in extensor retinaculum, and what runs through each one?
6 compartments. Radial to ulnar:
-EPB and APL
-ERCL, ECRB
-EPL
-Extensor indicis and extensor digitorum communis
-Extensor digiti minimi
-Extensor carpi ulnaris
What are the layers you go through during open carpal tunnel release?
Skin
Subcut fat
Palmar fascia
Flexor retinaculum (entire length must be divided)
What structures are at risk during open carpal tunnel decompression?
-Palmar cutaneous branch of median nerve (sensation to thenar eminence)
-Recurrent branch median nerve (motor branch to thenar muscles)
-Ulnar nerve as it passes through flexor retinaculum (with incision too far to ulnar side)
-Median nerve
-Superficial palmar arch
-Flexor tendons passing through carpal tunnel
Contents of anatomical snuffbox
Radial artery
Radial nerve
ECRL+ECRB tendons
Describe pathology of scaphoid fracture
-Avascular necrosis proximal pole
-Retrograde blood supply from distal pole via radial artery branches
-Can present after months with pain and stiffness
-Can progress to disruption neighbouring carpal attachments: ‘SNAC wrist’ (scaphoid non-union advanced collapse)
-Early detection + immobilisation in cast or ORIF reduces risk
Describe upper limb dermatomes
C4: Upper shoulder, over clavicle
C5: Lateral arm below deltoid
C6: Thumb and radial hand/forearm
C7: Fingers 2, 3, 4
C8: finger 5
T1: Medial elbow
Upper limb myotomes
C5 – Shoulder abduction
C6 – Elbow flexion
C7 – Elbow extension
C8 – Finger flexion
T1 – Finger abduction
What are the terminal branches of radial artery in hand?
-Radial artery divides into princeps pollicis and radialis indicis
-Forms radial side of deep palmar arch of hand
Which tendons of fingers are contained within a sheath? How far does it exend? What is function of flexor sheath? What is the clinical significance of this?
-Flexor tendons contained within synovial sheaths in hand
-Extend from A1 pulley in palm to A5 pulley at DIPJ
Infection in flexure sheath is devastating for 2 reasons:
1) -rigid fibro-osseous tunnel of flexor sheath cannot expand in presence of pus
-This leads to raised pressure + interruption of blood supply to flexor tendons.
-Ultimately leads to atrophic tendon ruptures
2) Scarring within flexor sheath following infection leads to adhesions between tendons and sheath
-leads to reduced tendon ROM, stiffness, loss of function
Describe the pathological process that commonly affects the palmar fascia
-Dupuytren’s contracture
-Palmar aponeurosis is susceptible to progressive hyperplasia and fibrosis, with subsequent thickening and shortening
-Leads to flexion deformity of one or more digits, with associated loss of function
What is pathological enlargement of PIPJ and DIPJ called?
PIPJ: bouchard’s nodes (RA)
DIPJ: Heberden’s nodes (OA)
Reflexes nerve roots
1,2 buckle my shoe (S1-S2 ankle jerk)
3,4 kick the door (L3-L4 knee jerk)
5,6 pick up sticks (C5, C6 biceps jerk)
7,8 lay them straight (wrist jerk)
Orientating cubital fossa:
-Medial epicondyle is more pointy (prominent)
-Basilic vein is more medial than cephalic vein is lateral, and travels further to reach median cubital vein
