Upper limb anatomy Flashcards
What is the clavicopectoral triangle
The last passageway is the clavipectoral triangle, which is an opening in the anterior wall of the axilla. It is bounded by the pectoralis major, deltoid, and clavicle. The cephalic vein enters the axilla via this triangle, while the medial and lateral pectoral nerves leave.
What are the boundaries of the antecubital fossa
Anticubital fossa
Borders
The cubital fossa is triangular in shape and consists of three borders, a roof, and a floor:
* Lateral border – medial border of the brachioradialis muscle.
* Medial border – lateral border of the pronator teres muscle.
* Superior border – horizontal line drawn between the epicondyles of the humerus.
* Roof – bicipital aponeurosis, fascia, subcutaneous fat and skin.
* Floor – brachialis (proximally) and supinator (distally).
What are the boundaries of the cubital tunnel
- Medial wall – medial epicondyle of the humerus.
- Lateral wall – olecranon of the ulna.
- Floor – elbow joint capsule and medial collateral ligament of the elbow.
- Roof – ligament spanning between the medial epicondyle and olecranon
The ligament forming the roof of the cubital tunnel is also known as the cubital tunnel retinaculum or the arcuate ligament of Osbourne. It is a band of fascia which runs between the ulnar and humeral heads of the flexor carpi ulnaris.
How many tendons does the carpal tunnel have
The carpal tunnel has 9 tendons
* The tendon of flexor pollicis longus
* Four tendons of flexor digitorum profundus
* Four tendons of flexor digitorum superficialis
Describe the anatomy of the extensor compartment
Compartment 1 tendon inflammation results in deQ Tenosynovitis
Compartment 2 contains Lister’s tubercle – a bony prominence of the distal aspect of the radius.
Compartment 3 forms the medial border of the anatomical snuffbox
What are the boundaries of the anatomical snuff box
As the snuffbox is triangularly shaped, it has three borders, a floor, and a roof:
* Ulnar (medial) border: Tendon of the extensor pollicis longus.
* Radial (lateral) border: Tendons of the extensor pollicis brevis and abductor pollicis longus.
* Proximal border: Styloid process of the radius.
* Floor: Carpal bones; scaphoid and trapezium.
* Roof: Skin.
The main contents of the anatomical snuffbox are the radial artery, a branch of the radial nerve, and the cephalic vein:
* Radial artery – crosses the floor of the anatomical snuffbox, then turns medially and travels between the heads of the adductor pollicis muscle.
o The radial pulse can be palpated in some individuals by placing two fingers on the proximal portion of the anatomical snuffbox.
* Superficial branch of the radial nerve
* Cephalic vein
2 heads rule
Median nerve passes through the 2 heads of the pronator teres as well as flex dig sup
ulnar artery apssess between 2 heads of flexor carpi ulnaris
How is the axillary artery divided
The main branches of the axillary artery include:
First Part
Superior thoracic artery
Second Part
Thoracoacromial artery
Lateral thoracic artery
Third Part
Subscapular artery
Anterior and posterior circumflex arteries
When does the axillary artery become the brachial artery
At the lower border of the teres major muscle. Immediately distal to the teres major, the brachial artery gives rise to the profunda brachii (deep artery),
Where are the parts of the brachial plexus found
Roots: Exit the intervertebral foramen between the anterior and middle scalene muscle
Trunks - Base of the post triangle of the neck. They lie over the 1st Rib behind the 3rd part of the subclavian artery
Divisions: Post to the middle third of the clavicle
Cords: related to the second part of Ax nerve
Terminal branches: Related to 3rd part of Ax nerve
Median cutaneous nerve roots
C8, T1
Thoracodorsal nerve roots
Posterior cord C6,C8
What is the ulnar paradox
The closer to the paw, the worse the claw. Injury at the wrist will spare the ulnar branch to the flex dig profundus and cause worsened clawing of the hand
Where dose the flexor retinaculum of the wrist attach
Proximally to the pisi and the tubercle of the scaphoid
Distally hook of hamate and trapezium
What prevents bow stringing of the flexor retinaculum tendons
Intricate fascial pulley system and the flexor retinaculum
What are the muscles that attach to the greater tuberosity
Supraspinatus, infraspinatus and teres minor GT
subscapularis LT
Where does the long head of the biceps brachii originate
Supraglenoid tubercle
Where do the pec major, lat dorsi and teres major attach
Surgical vs anatomical neck of humerus
What muscles attach to the coracoid process
Short head of biceps brachii, coracobrachialis and the pec minor
Where does the biceps tendon insert
Radial tuberosity, fans into the bicipital aponeurosis in the antecubital fossa
Under what ligament does the supraspinatus muscle commonly get impinged
Coracoacromial ligament
Triangular space vs triangular interval
Triangular interval - Radial nerve and profunda brachii
Triangular space - Circumflex scapular vessels
WHat nerve supplies the rhomboid muscles and where does it originate
Dorsal scapular nerve C5 brachial plexus
Action of the serratus anterior on the scapula
lateral rotation and protraction
Long thoracic nerve C5, C5 and C7
What is the surface anatomy of the coracoid process
Palpable guide to the deltopectoral groove. Glenohumeral tube is one finger breadth lateral to the coracoid process
The blood supply to the rotor cuff
Ant and post circumflex arteries, thoracoacromial as well as subscapular artery
What is the painful arc
Painful abduction between 60-120 degrees and is caused by supraspinatus tendonitis
Name the branches of the lateral cord of the brachial plexus
Lateral pec and lateral root of median nerve and musculocutaneous nerve
Branches of the medial cord
Median pec nerve, medial cutaneous nerve of the arm and forearm, median root of the median nerve and ulnar nerve
Branches of the posterior cord
Axillary and radial nerve
Upper subscapular nerve
Lower scapular nerve
THoracodorsal nerve
Name the boundaries of the axilla
Apex – also known as the axillary inlet, it is formed by lateral border of the first rib, superior border of scapula, and the posterior border of the clavicle.
Lateral wall – formed by intertubercular groove of the humerus.
Medial wall – consists of the serratus anterior and the thoracic wall (ribs and intercostal muscles).
Anterior wall – contains the pectoralis major and the underlying pectoralis minor and the subclavius muscles.
Posterior wall – formed by the subscapularis, teres major and latissimus dorsi.
What are the levels of the axillary lymph nodes
Level 1: Below pec minor
Level 2: Behind pec minor
Level 3: Above the pec minor
What are the structures that can be affected in an axillary node clearance
Axillary vein, Long thoracic
Thoracodorsal
Intercostobranchial - innervated the skin of the upper arm medial and posterior
What is the clavicopectoral fascia and what goes through it
It extends from the axillary fascia and encloses the pec min and maj as well as the subclavius.
Lat pec nerve, thoracodorsal trunk, cephalic vein and lymphatics pass through it
What are the boundaries of the cubital tunnel
Medial wall – medial epicondyle of the humerus.
Lateral wall – olecranon of the ulna.
Floor – elbow joint capsule and medial collateral ligament of the elbow.
Roof – ligament spanning between the medial epicondyle and olecranonz
What to do if there is a suspected scaphoid fracture
Immobilise for 6 weeks. if it is a distal pole fracture, for proximal pole, consider internal fixation.
What is the guyon’s canal
It is a space between the pisiform bone and the hamate
What are the points of attachment of the flexor retinaculum
Hook of hamate and pisiform bone on the ulnar side
Scaphoid and trapezium on the radial side
What structures pass OVER the carpal tunnel
Palmaris longus tendon, Cutaneous branch of the median nerve and superficial branch of the radial artery
WHat is the significance of the kaplans cardinal line
Superficial palmar arch lies distal to this lone and can be injured by incisions that cross this line.
Describe the palmar fascia
Superficial layer with long fibers
Intermediate with transverse fibers
Deep layer with vertical fibers
What is a trigger finger?
Unknown aetiology and disruption of the pulley system causes the flexor tendons to get stuck
What is a mallet finger
Disruption of the distal extensor tendons of the finger, there is pain and swelling in the fingers as well as an inability to extend the DIPJ
Splint for 6-8 weeks. Surgery may be required if there is a large bone fragment or poor alignment
What are some causes of EPL tendon rupture
RH, Fractures of the wrist, Gout, Systemic or local steroids
What are the radiological features of RA
Joint space narrowing, joint erosions, periarticular cysts, soft tissue swelling
Name some more deformities of the hand in RH
Boutonniere deformity and swan neck
Subluxation
What is the origin of the median nerve
It originates from the lateral and medial cords of the BP
C5-T1
Where does the ulnar nerve originate
Medial part of the brachial plexus
Describe the vascular segments of the liver
The liver is divided into 8 segments, each segment receives a branch of the heaptic artery, portal vein and a bile ductile
Segment 1-4 is considered the right lobe and 5-8 is considered the left lobe
What are the contents of the axilla
Axillary artery and vein
Lymph nodes 3 levels (level 1 is below, 2 is behind and 3 is above)
Brachial plexus
Fat
What is the clavicopectoral fascia
The clavipectoral fascia is a thin layer of fibrous tissue that surrounds the pectoralis minor muscle. It attaches superiorly to the clavicle and inferiorly to the axillary fascia. It is thus the suspensory ligament of the axilla below the pectoralis minor.
Four structures pierce the clavipectoral fascia.
Two structures pass in:
* cephalic vein
* lymphatic vessels.
Two structures pass out:
* lateral pectoral nerve
* thoracoacromial
What are the boundaries of the cubital fossa
The cubital fossa is a triangular intermuscular space bounded:
- superiorly by a line connecting the medial and lateral epicondyles of the humerus
- medially by pronator teres
- laterally by brachioradialis.
The floor of the cubital fossa is formed from the brachialis and supinator muscles.
The roof of the cubital fossa is made by the bicipital aponeurosis
Boundaries of the cubital tunnel
The cubital tunnel has a roof formed by the aponeurotic expansion of the two heads of flexor carpi unaris. This spans in an arcade from the medial epicondyle of the humerus to the olecranon process of the ulna. The floor is formed by the medial collateral ligament of the elbow, expanding from the medial border of the olecranon to the base of the epicondyle.
How is bowstringing of the tendons in the hand prevented
To prevent the flexor tendons from bow-stringing, there are a series of fascial
coverings that anchor the tendon to the bony skeleton, while still allowing the
tendons to glide smoothly. At the wrist there is the flexor retinaculum and on
the fingers there are the annular (A1–5) and cruciate (C1–3) pulleys
How can you test the flex dig sup and prof
The flexor digitorum profundus tendon inserts into the base of the distal
phalanx of the finger. It can be tested by asking the patient to flex the distal
interphalangeal joint of that finger. The flexor digitorum superficialis tendon
inserts into the base of the middle phalanx of the finger. Flexion at the proximal
interphalangeal joint can be by contraction of both the flexor digitorum
superficialis and the flexor digitorum profundus; to test the function of the flexor
digitorum superficialis muscle alone, the patient’s flexor digitorum profundus
must be inactivated by holding their other fingers out straight and asking the
patient to flex their unrestrained finger at the proximal interphalangeal joint.
(Remember ‘the superficialis splits in two to allow profundus passing through’.)
Which superficial flexor muscle is congenitally absent in around 10% of the population? What is the clinical significance of this
The palmaris longus is absent in around 10% of the population. This muscle
has no real functional significance and can therefore be used as a tendon graft.
Before harvesting this tendon graft it is wise to test for its presence while the
patient is still awake. Ask the patient to make the V-sign with their index and
middle fingers and then slowly flex their wrist. The palmaris longus tendon is
visible as a separate line just on the ulnar side of the flexor carpi radialis tendon.
What gives attachment to the flexor retinaculum
The flexor retinaculum attaches to the:
L hook of the hamate and the pisiform on the ulnar aspect (HAMPISS)
L lateral ridge of trapezium and the tubercle of the scaphoid on the radial
aspect. (TRAPSCAPH)
Which intrinsic muscles of the hand are not supplied by the ulnar nerve
lateral two lumbricals, opponens pollicis, abductor pollicis brevis and
flexor pollicis brevis (‘LOAF muscles’), which are supplied by the median nerve
What is the action of the lumbricals
They flex the metacarpophalangeal joint and extend the interphalangeal joints.
What is a duputreyns contracture
The palmar aponeurosis seems to be susceptible to progressive hyperplasia and
fibrosis, with subsequent thickening and shortening. This leads to a flexion
deformity of one or more of the digits, with associated loss of function. This
condition is known as Dupuytren’s contracture.
Trigger finger is different than this as it is a problem with the flexor pulley system
Where are parts of the BP found
Roots: exits from IV foramina between scalenus anterior and medius * Trunks: base of the posterior triangle of the neck behind the 3rd part of the subclavian artery * Divisions: behind middle ⅓ of the clavicle * Cords: related to the 2nd part of axillary artery
What are the different parts of the scapula
What is the insertion and innervation of the rotor cuff muscles
Supraspinatus: Suprascapular nerve and GT of humerus
Infraspinatus: Suprascapular nerve and GT of humerus
Subscapularis: Upper and lower subscapular nerve and LT of humerus
Teres minor: Axillary nerve and GT of humerus
What are the structures that attach to the coracoid process
Ligaments o Coracoclavicular (trapezoid, conoid) o Coracoacromial o Coracohumeral
* Muscles o Pectoralis minor (insertion) o Coracobrachialis (origin) o Short head of biceps (origin)
What are the muscles in the bicipital groove
‘PLT sandwich’ or ‘Lady between 2 majors’
* Teres major (medial lip) * Latissimus dorsi (floor) * Pectoralis major (lateral lip)
What is the upper end anatomy of the humerus
Distal humeral anatomy
Anatomical areas of the upper limb (bony landmarks)
Anatomy of the radius and ulna
What are the boundaries of the ulnar canal
- Medial (ulnar) – pisiform, flexor carpi ulnaris tendon, abductor digiti minimi muscle.
- Lateral (radial) – hook of hamate.
- Roof – palmar carpal ligament.
- Floor – flexor retinaculum, pisohamate ligament, and hypothenar muscles.
Explain the ulnar paradox
The ulnar paradox is a phenomenon that occurs when a high ulnar nerve lesion at the elbow causes less clawing than a low ulnar nerve lesion at the wrist. This is because a high lesion weakens both the hand muscles and the long flexors, while a low lesion only weakens the hand muscles.
In a high lesion, the medial half of the flexor digitorum profundus (FDP) is paralyzed, which slackens the fourth and fifth interphalangeal joints. This relaxes the hand and reduces the claw-like appearance, instead paralyzing the fingers in an extended position. This is called the ulnar paradox because it’s unexpected that a more proximal lesion would result in less deformity.
As the patient recovers, reinnervation along the ulnar nerve can cause the deformity to worsen
What is the blood supply to the acromioclavicular joint
- Suprascapular artery – arises from the subclavian artery at the thyrocervical trunk.
- Thoracoacromial artery – arises from the axillary artery.
What is the nerve supply to the sternoclavicular joint
The sternoclavicular joint is supplied by the medial supraclavicular nerve (C3 and C4) and the nerve to subclavius (C5 and C6).
What holds the distal radio ulnar joint together
Triangular fibrocartilage
