Upper Limb Flashcards
Name 1-15
Clavicle: The Conoid (Medial) and Trapezoid (Lateral) Ligaments form which ligament?
Coracoclavicular ligament (Corocoid process - Lateral Clavicle)
Which 3 Rotator Cuff Muscles attach to the Greater Tubercle?
And Which muscles attach to the intertubercular groove (Between greater and lesser tubercles)?
Greater Tubercle: Supraspinatus, Infrapinatus, Teres Minor
Lesser Tubercle: Subscapularis
What runs in the radial groove?
Radial nerve and profunda brachii artery.
(Mid-shaft fracture could damage both - leading to wrist drop and sensory loss over dorsal hand and lateral 3.5 fingers dorsally)
Which muscles attach to the shaft of the humerus?
Anterior: Coracobrachialis, Deltoid (Deltoid tuberosity), brachialis, brachioradialis
Posterior: Medial and lateral heads of tricep
What does the capitulum and trochlea articulare with?
*Where does the ulnar nerve pass
Trochlea - Ulna
Capitulum - Radius
*Ulnar nerve passes along the posterior side of the medial epicondyle
Name the 4 Areas
What muscle attaches to the radial tuberosity?
Biceps brachii muscle
Name the carpal bones
Ligaments of the glenohumeral joint
- Joint capsule (Glenoid cavity - neck of humerus)
- Glenohumeral ligament (Supraglenoid tubercle - blend w joint capsule)
- Coracohumeral (Coracoid - Greater tubercle humerus)
- Transverse humeral (Bridges intertubercular groove between greater and lesser tubercles)
- Coracoacromial
What is the clavipectoral fascia and what structures peirce it?
Membrane between clavicle and pectoralis minor.
Lateral: Coracoid process
Medial: fuses with external intercostal membrane of upper two spaces
Encloses subclavius
Forms costocoracoid ligament
Peirced by:
2 passing inwards - 1) Lymphatics from the infraclavicular nodes to the apical nodes of the axilla. 2) Cephalic vein
2 passing outwards - 1) Thoracoacromial vessels (Clavicular, humeral, acromial, pectoral a.). 2) Lateral pectoral nerve
Pectoralis Major:
- Origin
- Attachment
- Innervation
- Action
Origin:
Sterocostal Head - Anterior surface of manubrium+sternum, superior 6 costal scartilages and aponeurosis of external oblique muscle
Clavicular Head - Anterior surface of medial clavicle
Attachment:
Tendon into the lateral lip of intertubercular groove, into the anterior lip of the deltoid tuberosity and into deep fascia of arm
Innervation:
Medial and Lateral pectoral nerve (All 5 segments of brachial plexus - C5,6 clavicular head and C7-T1 sternocostal part)
Action:
Abdduction of arm. Medial rotation of arm
Sternocostal head in main adductor of arm.
Clavicular head assists in flexion.
Pectoralis Minor:
- Origin
- Attachment
- Innervation
- Action
Origin:
- 3rd-5th Ribs
Attachment:
- Short thick tendon in coracoid process
Innervation:
Medial pectoral nerve
Action:
Assists serratus anterior in protraction of scapule
*Axillary artery and brachial plexus cords lie underneith it
What structures do the medial and lateral pectoral nerves peirce?
Medial pectoral nerve peirces the pectoralis minor (and supplies it)
Lateral pectoral nerve peirces the clavipectoral fascia
Subclavius:
- Origin
- Attachment
- Innervation
- Action
Origin:
Costochondral junction of the first rib
Attachment:
Inferior sruface of middle clavicle
Innervation:
Nerve to subclavius (C5,6)
Action:
Stabilises clavicle. Prevents fracture damaging subclavian vein.
Trapezius:
- Origin
- Attachment
- Innervation
- Action
Origin:
Skull, Nuchal ligament, spinous processes C7-T12
Attachment:
- Lateral 1/3 clavicle, medial border of acromion, superior lip of crest of scapular spine
Innervation:
Accessory nerve (C1-5) and branches from the cervical plexus (C3/4)
Action:
All fibres: Retract scapula
Upper fibres: elevate scapula and rotates it during abduction
Lower fibres - pull scapula inferiorly
Latissiumus Dorsi:
- Origin
- Attachment
- Innervation
- Action
Origin:
Spinous processes T7-12, supraspinous ligaments of lumbar and sacral vertebrae, posterior liac crest, thoracolumbar fascia and inferior 3 ribs
Attatch:
Tendon in intertubercular sulcus of humerus
Innervation:
Thoracodorsal nerve (C6,7,8)
Action:
Extends, adducts and medially rotates arm
Triangle of Auscultation Borders
Lateral Border of Trapezius
Vertebral border of scapula
Upper horizontal border of latissimus dorsi
Importance: Relative thinning of the musculature of the back, situated along the medial border of the scapula which allows for improved listening to the lungs.
Rhomboid Major and Minor
Rhomboid Major Origin:
Spinous processes of T2-5 vertebrae
Rhomboid Minor Origin:
Spinour provess C7-T1 vertebrae
Attach: Major: Inferior angle and Medial border of scapula. Minor: Medial border.
Innervation: Dorsal Scapula Nerve (from C5 root, passes through scalenus medius, runs down to the levator scapulae (supplies it) and lies on the serratus posterior
Action: Draw scapula medially and upwards
Test: With the hand on the hip or behind the back the patient pushes the elbow backwards against resis tance and braces the shoulder back. The muscles are palpated at the vertebral border of the scapula; being deep to trapezius they are not always visible. If the rhomboids of one side are paralysed the scapula of the affected side remains farther from the midline than that of the normal side.
Levator scapulae
- Origin
- Attachment
- Innervation
- Action
Origin:
- Transverse processes of C1-4 vertebrae
Attach:
- Medial border scapula
Innervation:
Dorsal scapula nerve (C5) + Cervical plexus C3,4
Function:
Elevates Scapula, rotates neck
Serratus anterior
- Origin
- Attachment
- Innervation
- Function
Origin:
Lateral aspects of ribs 1-8
Attach:
costal surface of medial border of scapula
Innervation:
Long thoracic nerve (C5,6,7)
Action: Protracts scapula and laterally rotates scapula
Describe the sternoclavicular joint. Why is it an atypical synovial joint?
Synovial joint between clavicle, manubrium of sternum and part of the 1st costal cartilage
Atypical synovial joint as the articulating surfaces covered with fibrocartilage not hyaline cartilage
Seperated into 2 cavities by a Fibrocartilaginous articular disc
Ligaments and innervation of the sternoclavicular joint
Ligaments:
- Anterior + Posterior sternoclavicular ligaments
- Interclavicular ligament
- costoclavicular ligaments
Innervation:
Medial supraclavicular nerve (C3,4)
Action:
- Elevation and depression (Shrugging)
- protraction and retraction
- rotation (When arm elevated)
The Axilla Region Borders and Contents
Apex - Lateral 1st rib, clavicle, superior border of scapula
Lateral - Intertubercular groove of humerus
Medial - upper: Serratus anterior, lower: 4th rib
Anterior - pectoralis major, minor, subclavius, clavipectoral fascia
Posterior - Subscapularis, teres major, latissimus dorsi
Contents:
- Axillary vein (medial to artery)
- Axillary artery
- Brachial Plexus (Cords)
- Biceps brachii and coracobrachialis
- Axillary lymph nodes
Acromioclavicular joint
- Ligaments
- innervation
- action
Similar to the sternoclavicular joint, the articulating surfaces covered by fibrocartilage
Ligaments:
- Coracoclavicular ligament (Conoid and trapezoid)
- Acromioclavicular ligament
Nerve supply
- Lateral supraclavicular nerves (C4)
What are the rotator cuff muscles?
Describe there innervation, origin and attachments, function
What is the quadrangular and triangular space in the shoulder?
Quadrangular Space:
Lies between the subscapularis and teres major
Transmits the axillary nerve, with the posterior circumflex humeral artery and vein
Triangular space:
Below the teres major and between the humerus and long head of triceps
Transmits the radial nerve and profunda brachii vessels
Axillary artery:
- When does the subclavian artery become the axillary artery
- Whats the fascia that covers the axillary artery called?
- At the lower border of what muscle does it become the brachial artery?
- Subclavian artery
- Axillary sheath
- Teres Major
Outline the surgical approach to the axillary artery
First part of the artery exposed by splitting clavicular head of pectoralis major and incising the clavipectoral fascia
The rest of the artery is approached through the axilla, in the groove between coracobrachialis and long head of triceps
Branches of the axillary artery
- First part: Superior thoracic artery (supplies both pectoral muscles)
- Second part:
- Thoracoacromial artery (peirces clavipectoral fascia then seperates into clavicular, deltoid, acromial, pectoral branches)
- Lateral thoracic artery (breast and pectoral muscles) - Third Part: Subscapular (largest branch, runs down posterior axillary wall giving off circumflex scapula artery) and anterior/posterior circumflex humeral arteries (circle humerus and supply shoulder region)
DRAW THE BRACHIAL PLEXUS
The five roots lie behind scalenus anterior muscle and emerge between it and scalenus medius to form the trunks which cross the lower part of the posterior triangle of the neck. Each of the three trunks divides into an anterior and a posterior division behind the clavicle. Here, at the outer border of the first rib, the upper two anterior divisions unite to form the lateral cord, the anterior division of the lower trunk runs on as the medial cord, while all three posterior divisions unite to form the posterior cord. These three cords enter the axilla above the first part of the artery, approach and embrace its second part, and give off their branches around its third part.
How many groups of lymph nodes in axilla
- Average number 35, may be over 50
i) Anterior (pectoral group)
ii) Posterior (Subscapular group)
iii) Lateral group
iv) Central group
v) Apical group
Breast anatomy: What is the blood supply to the breast?
- Internal thoracic (mammary) artery
- Lateral thoracic artery
- Thoracoacromial artery
Breast Anatomy: Mammary glands are modified sweat glands. They consists of a series of ducts and secretory lobules (15-20). What are these ducts called?
Lactiferous ducts
Breast anatomy: The fibrous stroma condenses to form what ligament?
Suspensory ligaments of cooper.
Function is to secure the breast to the dermis and underlying pectoral fascia
seperate secretory lobules of the breast
What nodes does lymph from the breast drain?
Axillary nodes (75%)
Parasternal nodes (20%)
Posterior Intercostal nodes (5%)
Deltoid:
- Origin
- Attachment
- Innervation
- Function
Origin:
Scapula (Acomion and crest of scapula spine), lateral 1/3 clavicle
Attach:
Deltoid tuberosity on lateral humerus
Innervation:
Axillary nerve
Function:
Anterior: flexion
Posterior: extend
Middle: Major abductor (Takes over from suprispinatus after 15 degrees)
Describe the scapular anastamosis
The dorsal scapular and suprascapular arteries arise from the third and first parts of the subclavian, and the subscapular from the third part of the axillary artery. They and the circumflex scapular anastomose on both surfaces of the scapula.
Describe the brachial plexus roots, subclavian artery and vein in relation to the scalene muscles
Subclavian vein runs infront of anterior scalene
Subclavian artery and roots of brachial plexus run behind anterior scalane and infront of middle scalene muscle
Course of the cephalic vein
No accomanying artery
Between anterior deltoid and pectoralis major then under pectoralis major
joins other veins to become subclavien vein
Subclavian vein relative to pectoralis minor, anterior scalene and clavicle
Passes beneath pectoralis minor, over scalene anterior and under subclavius muscle and clavicle
Joins Internal jugular vein to become braciocephalic vein
Describe the shoulder joint and ligements involved
Synovial joint
Between humeral head and glenooid fossa (4:1 ratio)
Stabilised by the glenoid labrum
Covered in a joint capsule (Surrounds glenoid labrum and surgical neck of humerus)
Synovium covers attaches around the labrum and lines the capsule and humerus. It herniates through a hole to communicate with the subscapularis bursa and invests the long head of biceps tendon
Ligaments:
- Glenohumeral ligemnts
- Coracohumeral ligament
- Transverse humeral ligament
- Coracoacromial ligament
Important shoulder bursae
Subacromial bursae: located inferiorly to the deltoid and acromion and superior to the suprispinatus tendon and joint capsule
Subscapular bursae: located between subscapularis tendon and scapula
Infraspinatus bursae
Subdeltoid bursae
Subcutaneous acromial bursa
Coracobrachial bursa
Subtendinous bursa of subscapularis
Muscle tendons in the joint capsule of the glenohumeral joint
long head of biceps (Supralenoid tubercle)
loong head of triceps (Infraglenoid tubercle)
Shoulder abduction muscles
- Supraspinatus (15 degrees)
- Middle deltoid
Adducting muscles of shoulder
- Pectoralis major
- Latissimus dorsi
coracobrachialis
Flexors of shoulder
Clavicular head of pectoralis major
Anterior deltoid
Coracobrachialis
Biceps
Extensor of shoulder
Latissimus dorsi
Posterior deltois
long head of triceps
Rotation of shoulder
Lateral: Infraspinatus, teres minor
Medial: Subscapularis
Coracobrachialis
- Origin
- Attachment
- Innervation
- Function
Origin:
Coracoid process
Attach:
Medial shaft humerus
Innervation:
Musculocutaneous nerve (actually passes through the muscle *Care in surgical approach)
Function:
Weak Flexion and adduction of shoulder
Biceps:
- Origin
- Attachment
- Innervation
- Function
Origin:
Long head - Supraglenoid tubercle (emerges beneath the transverse ligament at the upper end of the intertubercular groove)
Short head- Corocoid process (lateral to coracobrachialis)
Attachment
Posterior border of the tuberosity of the radius and fascia of the forearm via the bicepital aponeurosis
Inntervation:
Musculocutaneous nerve
Function:
Flexion of elbow and shoulder and
supination of elbow (when elbow not in full extension)
Brachialis
- Origin
- Attachment
- Innervation
- Function
Origin:
from theanterior lower 2/3rds of humeral shaft and medial intermuscular septum
Attachment:
Ulna tuberosity and coronoid process
Innervation:
Musculocutaneous nerve (some of lateral part by radial nerve)
Function:
Flexion at elbow
Branches of brachial artery
Proximal:
Profunda brachii (Leaves through lower triangular spave to run in the radial groove with the radial nerve). Supplies the triceps.
Superior ulnar collareral artery (accompanies ulnar nerve)
Inferior ulnar collateral artery
Distal:
Radial a.
Ulnar a.
Venous system of arm
Describe the sources of the Superficial and Deep veins
Superficial:
Basilic vein - originates from dorsal venous network on hands. Ascends medially. At border of teres minor it travels deep. Combines with brachial vein to become axillary vein.
Cephalic vein - arises from dorsal venous network on hands. Ascends antero-lateral. At the shoulder it travels between the deltoid and pectoralis major. Terminates by joining the axillary vein.
At the elbow, the cephalic and basilic vein is connected by the median cubital vein
Deep veins: (Beneath deep fascia)
They are paired veins, each side of an artery (venae comitantes)
Brachial veins (Each side of brachial artery)
*Perforating veins run between the deep and superficial veins
Triceps
- origin
- attachment
- innervation
- function
origin:
- long head: Infraglenoid tubercle
- Lateral head - Posterior humerus from surgical neck to deltoid insertion
- Medial Head - Medial radial groove humerus and posterior humerus below
Attach:
Olecranon of ulna
Innervation:
Radial nerve (c7,8)
Function:
Extension elbow
Contents of cubital fossa (Lateral to medial)
Really Need Beer To Be At My Nicest
Radial Nerve
Bicep Tendon
Brachial Artery
Median Nerve
Radial Nerve
- Path
- Motor function
- Sensory function
Path:
- Continuation of posterior cord of brachial plexus
- leaves shoulder through triangular area
- Descends arm, in radial groove
- Wraps around humerus laterally
- enters the forearm anteriorly over the lateral epicondyle of humerus
- divides into two branches in cubital fossa
i) Deep - (motor) - Travels between brachialis and brachioradialis, then travels through supinators two heads to go deep. gives of posterior interosseous
ii) Superficial (seonsory) - Between brachialis and brachioradialis then runs along lateral forearm, radial to radial artery giving off branches
Motor function:
- Triceps
- Brachioradialis
- extensor carpi radialis longus
- Posterior forearm muscles
Elbow joint ligaments and nerve supply
Radial collateral - Lateral epicondyle, blends with annular ligament
Ulnar collateral - Medial condyle to coronoid process and olecronon
Annular ligament - attaches to radial notch of ulna and its fibres encircle head and neck of radius, which is free to rotate within it. Superiorly it blends with capsule of joint
Anterior compartment Forearm: Superficial muscles
- Origin
- Attachment
- Innervation
- Function
Cubital fossa borders
(Triangular shaped)
Lateral - Brachioradialis
Medial - Pronator teres
Superior border - Imaginary line between epicondyles
Floor - Brachialis (proximal), Supinator (distal)
Roof - skin, fascia, bicepital aponeurosis
What structures lie on top of the cubital fossa
Medially, on the biceptial aponeurosis
- Median basilic vein
- Medial cutaneous nerve of forearme medial to vein
Laterally
- Lateral cutaneous nerve of forearm and median cephalic vein
Deep compartment of anterior forearm muscles
*FDP - Origin - medial surface of olecranon and upper 3/4 of medial/ anterior ulna + interosseous membrane (Tendon to index seperates in forearm, others in palm)
How can you destinguish between the flexor carpi radialus and flexor pollicis longus in the wrist
Flexor pollicis lonugs tendon receives fleshy fibres into its radial side to a point just above the wrist (FCR doesnt)
What is the space of parona
In front of the pronator quadratus and deep to the long flexor tendons of the fingers is a spave into which the proximal parts of the flexor synovial sheaths protrude
Space becomes involved in proximal extension of synovial sheath infections
Ulnar nerve
- Path
- Motor
- Sensory
Path:
Continuation of medial cord (C8, T1)
Travels medial upper arm, through medial intermuscular septum
Posterior to the medial epicondule
in forearm, pierces the two heads of flexor carpi ulnaris and travels alongside ulnar
Lies under flexor carpi ulnaris with ulnar artery on its radial side
Motor:
- Ant. Forearm (Flexor carpi ulnari, Half Flexor digitorum profundus)
- Hand (Hypothenar, medial two lumbricals, adductor pollicus, interossei of hand, palmaris brevis)
3 Branches in the wrist/ hand:
i) Palmar cutaneous branch
ii) Dorsal cutaneous branch
iii) Superficial branch (Supplies palmar brevis and finger tips)
Median nerve
- path
- motor
- sensory
Medial and lateral cords of brachial plexus (contains fibres from all 5 roots)
Descends down arm initially laterally to brachial artey, halfway it crosses over to medial side of brachial artery.
Enters forearm via cubital fossa (medial side)
In forearm travels between flexor digitorum profundus and superficialis.
Two major branches in forearm
i) Anterior interosseous n. (Motor - ant. forearm)
ii) Palmar cutaneous n. (Sensory - skin palm)
Two branches in carpal tunnel
i) Recurrent branch (Motor - Thenar muscles)
ii) Palmar Digital cutaenous branch (Sensory + motor - two lumbircals and fingertips 3.5)
Arteries of upper limb
Right subclavian artery arises from Braciocephalic trunk
Left subclavian artery from arch of aorta
Once crosses 1st rib the subclavian artery becomes the axillary artery
Axillary artery passes under pectoralis minor (in axillary sheath). Gives off branches (other card)
Axillary artery reaches lower border of teres major and becomes brachial artery.
Immediately distal to teres major the profunda brachii branch comes off (travels posterior arm)
Brachial artery descends down the arm posterior to median nerve. As it corsses cubital fossa underneath brachialis it terminates into radial and ulnar arteries.
Radial a. supplies posterior forearm. Passes over muscles of anterior forearm then disappears beneath tendons of abductor pollicis longus nad extensor pollicis brevis to corss anatomical snuff box.
Ulna a. supplies anterior forearm. Passes deep to pronator teres. Cheif branch is the common interosseous a.
The two arteries anastamose in the hand, forming the superficial palmar arch and deep palmar arch.
Also anastaomse in the wrist through the posterior and and anterior carpal arch
Muscculocutaneous nerve
- Path
Arises from lateral cord of brachial plexus
leaves axilla and peirces coracobrachialis
passes down arm anterior to brachialis and deep to bicep brachii (innervating both)
continues into forearm as ‘lateral and medial cutaneous nerve of forearm’ (sensory lateral forearm as seen in pic)
Axillary nerve
- Path
- Motor
- Sensory
Continuation of posterior cord
Lies posterior to axillary artery
Descends to inferior border of subscapularis and exists axilla through quadrangular space
(Quad space: Superior [subscap, teres minor], inferior [teres major], lat. [humerus neck], med. [long head of triceps])
Terminates into two branches:
Anterior terminal branch - innervates deltoids
Posterior terminal branch - innervates teres minor and skin over inferior deltoid (continues as sensory n. - upper lateral cutaenous nerve of the arm) Which innervates skin over inferior deltoid
What muscles are pronators;
and what muscles are supinators
pronators: ponator teres, pronator quadratus (median n.)
supinators: biceps, supinator (musculoc n. + radial n.)
Proximal and dital radioulnar joints
- What movements are they capable of?
- What joins the radius and ulna
Proximal radioulnar joint:
- Quadrate ligament - between neck of radius, procimal to tuberosity and upper part of supinator fossa of ulna
Distal radioulnar joint:
Closed distally by triangular fibrocartilage. Attached to base of ulna notch of radius and ulnar styloid
This joints are responsible for supination and pronation
Superficial muscles of posterior forearm
Deep muscles of posterior forearm
- origin
- attachment
- innervation
- function
What is the anatomical snuffbox
If thumb is extended (drawing up extensor tendons) it created a cavity
Medial - extensor pollicis longus tendon
Lateral - abductor pollicis longus/ extendor pollicis brevis
Proximal - styloid process of radius
roof- skin
- floow - carpal bones (Scaphoid, trapezium)
Significance:
The (superficial) cutaneous branches othe radial nerve cross the tendons
The cephalic vein begins in the snuffbox from the dorsal vneous network
the radial artery lies on the floor
Extensor retinaculum attachments
Above styloid process of radius
attached to pisiform and triquetral bones
Carpal tunnel
- borders
- contents
- significance
Borders:
- flexor retinaculum
- deep carpal arch: scaphoid, trapezium,hamate, pisiform
Contents:
9 tendons: Flexor digitorum profundus (4), Flexor digitorum superficialis (4), flexor pollicis longus (1)
FDS and FDP share same sheath. FPL own sheath.
Median nerve
Radiocarpal joint (wrist joint)
- Type of joint
- Ligaments
Synovial Joint. *Ulna is not part of the joint, it articulates with the radius, just proximal to the wrist joint
Between radius with scaphoid, lunate, triquetral bones
A simple capsule surrounds the joint
Ligaments:
- Palmar radiocarpal
- Dorsal radiocarpal
- Ulnar collateral (Ulnar styloid to triquetrum and pisiform)
- Radial colateral (Styloid process to scaphoid and trapeium)
Nerve supply - posterior interosseous (radial) and anterior interosseous (median)
Adduction: flexor and extensor carpi ulnaris
Abduction: abductor pollicis longus, flexor carpi radialis
what is the palmar aponeurosis
Degenerated tendon of palmaris longus
Extends from flexor retinaculum where it fans out towards the bases of the fingers (proximal phalanges)
Thinnest over hypothenar region
Function is mechanical (attaches to skin of hand to improve grip)
What is the flexor retinaculum? What is the ulnar nerves path in relation to it? keeping in mind the median nerve goes through the carpal tunnel
Strong band attached from Scaphoid and trapezium laterally to pisiform and hamate medially
*Pisiform only bone that gives rise to both flexor and extensor retinaculum
Th ulnar nerve lies on the retinaculum alongside the pisiform bone, with the ulnar artery on its radial side. (known as Canal of Guyon) Nerve then divides into a superficial and deep branch at distal border of retinaculum
Thenar muscles
- origin
- attachment
- nerve supple
Hypothenar muscles
- Origin
- Attachment
- Innervation
what is i the superficial palmar branch?
it is the artery that is the continuation of the ulnar artery in the palm
gives off palmar fidital arteries that supply the fingers
Digital nerves where are they ?
Lying immediately deep to the superficial palmar arch are the common palmar digital nerves
they pass distally to the webs, between the slips of the palmar aponeurosis and divide like the arteries into proper palmar digital nerves
Symptoms of carpal tunnel syndrome
Caused by continual swelling in the synovial sheaths
symptoms:
- Wasting and weakness of thenar muscles (loss of opposition of thumb)
- Anaesthesia over three and a half digits on the thumb side of the hand
- Note there is NO Anaesthesia over the thenar eminence (supplied by palmar branch of median nerve which doesnt pass through carpal tunnel)
Sugical division of the retinaculum relieves pressure and symptoms
*Note must be differentiated from median nerve damage higher up which would cause damage to the palmar cutaenous branch resulting in weakness of the relevant flexor muscles in the forearm (flexor pollicis longus) - in carpal tunel syndrome the terminal phalanx of the thumb can be flexed with normal power, but with higher lesions this power is lost
Lumbricals
- origin
- Attachment
- innervation
Adductor pollicis and palmar brevis
- origin
- attachment
- innervation
Interossei of hand
- origin
- attachment
- innevation
- action
*Note ontop of abduction and adduction they have same function as lumbricals - flexion of MCP and extention of prox interphalangeal joint
Radial artery in the hand
- path
- branches
Leaves lower end of radius and slopes across snuffbox over trapezium
passes into hand between two heads of first dorsal interosseous muscle
Branches
i) arteria radialis indicis (radial side of index finger)
ii) princeps pollicis - either side of thumb
The main trunk of radial artery then forms the deep palamr arch (anastomosing with deep branch of ulnar artery)
Ulna Tunnel (Cubital tunnel)
- borders
- contents
Oval shaped
- Medial wall - medial epicondyle of humerus
- Lateral wall - olecranon of ulna
- Floor - elbow joint capsule and medial collateral ligament of elbow
- Roof - ligament spanning between medial epicodyle and olegranon (cubital tunnel retinaculum)
Contents
- ulnar nerve
Guyon’s canal (ulnar canal)
- borders
- contents
Extends from proximal pisoform to origin of hypothenar muscles at hook of hamate
Borders:
Medial (ulnar) - Pisiform, flexor carpi ulnaris tendon, abductor digiti minimi
Lateral - hook of hamate
Roof - palmar carpal ligament
Floor - retinaculum, psiohamate ligament, hypothenar muscles
Contents:
- ulnar nerve - bifurcates in canal to superficial (sensory) and deep (motor) branches
- ulnar artery (lateral to nerve)
- venae comitanted of ulnar artery
- lymphatic vessels
Sheaths of flexor tendons
On the tendon of flexor pollicis longus the sheath extends from above the flexor retinaculum to the insertion of the tendon into the terminal phalanx of the thumb.
The tendons of the superficial and deep flexors are together invested with a common synovial sheath that is incomplete on the radial side (FDS, FDP).
From the metacarpal heads to the distal phalanges FPL, FDS and FDP are enveloped in a fibrous flexor sheath
Superficial and deep transverse metacarpal ligaments of hand
Superficial transverse metacarpal ligament:
Lies beneath palmar skin
The ligament supports the fold of skin at the web
Digital vessels and nerves lie immediately deep to ligament
Deep transverse metacarpal ligament joins the palmar ligaments of the metacarpal phalangeal joints
Ligaments of wrist
Palmar radiocarpal - anterior hand. form radius to both rows of carpal bones
Dorsal radiocarpal - poserior. Radius to both rows of carpal bones
ulnar collateral - ulnar styloid process to triquetrum and pisiform
radial collateral - radial stylois to scaphor and trapezium
Summary of nerves on arm
Describe the sympathetic nerve supply of the upper limb
A grey ramus communicans joins each root of the brachial plexus and these sympathetic fibres hitch-hike through the plexus and its branches and remains in the nerves until very near their area of supply
Brachial Plexus Injury
- what are common ones seen and how do they present
Whole limb immobile and anaesthetic
If serratus anterior and rhomboids are in action, damage is distal to the roots of origin
If supraspinatus and infraspinatus espace, the damage is distal to the upper trunk
Commonest traction injury to the plexus is at C5,6 (Erb’s Paralysis) which can be caused at birth (Erb-Duchenne paralysis). The supinators are paralysed so that the arm hangs by the side, medially rotated, extended at the elbow and pronated with loss of sensation on lateral arm and forearm (Musculocutaneous n., axillary n.)
Damage to the lowest roots (C8,T1) results in small muscles of the hand being effected leading to a claw hand and inability to extend the fingers, with sensory loss on the ulnar side of the forearm.
Axillary Nerve Injury
- What causes it and how does it present
Damaged in 5% of dislocations of the shoulder, fractures of proximal humerus or iatrogenic
Results in paralysis of the deltoids and and egg-shaped anaesthesia over the outer side of the upper arm below the acromion
Radial nerve injury
- How it is injured and how it presents
Injured my fractures of shaft of humerus
Transient presentations from crutches or saturday night palsy
*Note Branches for triceps leave before nerve reaches the humerus (so a mid shaft fracture won’t effect elbow extension) but may be effected in higher lesions
Motor: Wrist drop (Thus loss of grip stregnth)
Sensory: loss is minimal, usually a coin-shaped area overlying first dorsal interosseous (Apparently there is a fair bit of overlap from ular and median n.)
Ulnar nerve
Most common at elbow or wrist
Wrist:
Motor - Claw hand from paralysis of lumbricals and interossei (Hyperextension of MCP joint and Flexion of Interphalangeal joints of ring and little finger. THa claw is brought about by unopposed action of the extensors and flexor digitorum
Wasting of the interossei becomes evident on dorsum of hand.
Sensory: ulnar side of hand (medial 1.5 fingers)
(Test for abduction to prove this)
Injury at the elbow:
Motor: Gives straighter fingers as the ulnar half of the flexor digitorum profundus is out of action and cant fles the distal interphalangeal joints (test for distal Interphalangeal joint flexion to prove this)
Median nerve injury
- How it gets injured and how it presents
Injury at wrist:
Motor:
Wasting of the thenar eminence (do note the flexor pollicis brevis can sometimes be innervated by ulnar nerve, so the most obvious wasting is the abductor pollicis brevis which is always innervated by median n.)
(if testing, do not test flexor pollicis brevis, test abduction of thumb)
Sensory:
- Anaesthesia over three and a half digits on the thumb side of the hand
- Note there is NO Anaesthesia over the thenar eminence (supplied by palmar branch of median nerve which doesnt pass through carpal tunnel)
Lesion below anterior interosseous nerve:
Recurrent branch of median nerve
- Innervates muscles of the thenar eminence
- Damaged with lacerations of the radial-sided wrist and proximal palm
- Results in loss of thumb flexion, opposition, and abduction without sensory or other motor deficits
Median claw: Distal median nerve injury causes palsy of the lumbricals I and II with preserved function of extrinsic flexors. This imbalance leads to permanent flexion of the index finger and the middle finger (aggravated when trying to extend the fingers).
Ape hand: inability to oppose and abduct the thumb due to injury of the proximal or distal median nerves impairing the thenar muscles’ functions
Palmar cutaneous nerve
- Purely sensory nerve arising from median nerve proximal to the carpal tunnel
- Provides sensation to the palm
Lesion above anterior interosseous nerve:
Wasting of the front of the forearm because of the long flexors (Excepts flexor carpi ulnaris and 1/2 FDP) and the pronators are paralysed
Hand of benediction: when asked to make a fist, the patient can only flex the ring finger and the little finger due to
- Loss of thumb opposition and abduction
- Loss of index and middle finger flexion
Impaired wrist pronation and flexion
Thenar muscle atrophy (chronic injury)
Ossification of the scapula
esenchyme chondrifies at the sixth week, when the whole scapula becomes cartilaginous. A bony centre appears in the eighth week at the thick part of the lateral angle and gradually enlarges. At birth the blade and spine are ossified, but the acromion, coracoid process, medial border and inferior angle are still composed of hyaline cartilage. Secondary centres appear in these places, and around the lower margin of the glenoid cavity, at about puberty, and all are fused by 25 years. The centre at the base of the coracoid process ossifies at 10 years and fuses, across the glenoid cavity, soon after puberty.
Ossification of humerus
The whole is cartilaginous at the sixth week. A primary centre appears in the centre of the shaft at the eighth week. Upper and lower ends are cartilaginous at birth. Secondary centres appear at both ends. For the upper end they are in the head during the first year, greater tuberosity at the third and lesser tuberosity at the fifth year. These three fuse by the seventh year into a single bony epiphysis, hollowed to fit a conical projection of the bony shaft. The epiphyseal line skirts the bone across the lowest margin of the articular surface, cutting across the tuberosities. This is the growing end of the bone; fusion occurs at about 20 years. At the lower end four centres appear. There is one for the capitulum and lateral ridge of the trochlea at the second year, one for the medial epicondyle at the fifth year, the remainder of the trochlea at the twelfth and the lateral epicondyle at the thirteenth year. The medial epicondyle remains a separate centre, separated by a downward projection of the shaft (in contact with the ulnar nerve) from the other three, which fuse together. Union with the shaft occurs at about 18 years.
Ossification of the radius
The whole appears in cartilage at the sixth week, and a centre appears in the middle of the shaft at the eighth week. At birth both ends are carti laginous; the lower is the growing end. A centre appears in the lower end at the end of the first year, and fuses at 20 years. This epiphyseal line is extracapsular; it runs transversely through the base of the styloid process and lies above the ulnar notch. The centre for the head appears at 4 years and fuses at 12; the epiphyseal line is at the junction of head and neck.
Ossification of the ulnar
Cartilage at the sixth week, a centre for the shaft appears at the eighth week. The head is not ossified until the sixth year. This is the growing end and does not fuse with the shaft until 20 years. The upper end is curious in that it shows only a small epiphysis at the proximal surface of the olecranon; this appears at about the tenth year and fuses at 18 years or earlier. The massive upper end of the ulna grows in size and adapts its shape to the trochlea as one mass of bone, unaided by growth and adjustment at an epiphyseal line.
Ossification of the carpal and hand bones
Unlike the tarsus the carpus is all cartilaginous at birth.Each carpal bone ossifies from one centre. The largest bone, the capitate, ossifies first (first year) and the smallest, the pisiform, ossifies last (tenth year). The others ossify in sequence, according to their size, at approximately yearly intervals (hamate, triquetral, lunate, trapezium, scaphoid, trapezoid), so the whole carpus, except the sesamoid pisiform bone, is ossified by the seventh year. The shafts of all the metacarpals and phalanges ossify in utero, so that at birth there is a cartilaginous epiphysis at the base of every bone except the metacarpals of the palm (second, third, fourth and fifth), where the epiphysis is at the head. Note that the thumb metacarpal ossifies like a phalanx. The cartilagi nous epiphyses ossify at the second to third year and fuse at 20 years. The tuberosity of each terminal phalanx ossifies in membrane.
Myotomes of upper limb
Shoulder:
Abduction C5
Adduction C6,7,8
Elbow
Flexion C5,6
Extension C7,8
Forearm
Supinate C6
Pronate C7,8
Wrist
Flexion C6,7
Extension C6,7
Fingers and thumb (long tension)
Flex C7,8
Ext C7,8
Intrinsic muscles of Hand T1
Dermatomes of upper limb
