Download 1 Anatomy – Upper Limb – Joints

Anatomy – Upper Limb – Joints
Sternoclavicular joint
Type Synovial/saddle (atypical - fibro not hyaline)
Articulation
Medial end clavicle, manubrium, first costal cartilage
Separated by fibrocartilaginous articular disc
Capsule Fibrous, surrounds entire joint, thickened in front and behind → ant and post SC ligaments
Ligaments
Ant and Post Sternoclavicular ligaments
Interclavicular - between clavicles and across jugular notch
Costoclavicular - MAJOR STABILISER, clavicle to 1st costal cartilage. 2 parts, ant and post
Artery Internal thoracic and suprascapular
Nerve Medial supraclavicular from cervical plexus; nerve to subclavius
Movement Minimal – ant/post, sup/inf
Stability capsule and ligaments, esp costoclavicular
Acromioclavicular Joint
Synovial, atypical (fibro not hyaline)
Thick superior capsule to form AC ligament + incomplete fibrocartilage disc
Ligament:
AC lig: strengthens joint sup; Coracoacromial lig
coracoclavicular lig: Conoid part, Trapezoid part - MAJOR STABILISER
Action: gliding passive and 20deg rotation scapula
Nerve: lateral supraclavicular C4
Stability: ligaments, esp coracoclavicular ligament
Shoulder (glenohumeral) Joint
Type: synovial, ball and socket
Head humerus and glenoid scapular - 4:1 disproportion - Fossa deepened by glenoid labrum – ring fibrocartilage
Capsule: strong sup, weak inf
attached to margins glenoid and anatomical neck, down 2cm med; long tendon biceps intracapsular/extrasynov
Nerve: subscapular, suprascapular, axillary, lateral pectoral
Artery: circumflex humerals (3rd part axillary), suprascapular
Bursae: 1) Subscapular 2) Subacromial 3) Infraspinatus 4) Supraspinatus
Ligaments:
1) Coraco-acromial (extrinsic) - coracoid --> acromion; subacromial bursa under (communicates)
2) Coracohumeral - superior; coracoid process --> humerus
3) Glenohumeral (intrinsic) - anterior; supraglenoid tubercle --> humerus
4) Tranverse humeral (intrinsic) - greater --> lesser tubercle
Movement: Considerable freedom due to ball and socket, large humeral head, shallow glenoid
Movt other structures shoulder girdle incl scapular/clavicle contribute
Flexion
Clavic head pec major, Ant fibres deltoid, Assisted by coracobracialis and short head bicep
Extension
Latissimus dorsi, Teres major, Post fibres deltoid
Abduction
Acromial fibres deltoid; Supraspinatus initiates/holds humerus against glenoid fossa
Adduction
Pect major, Lat dorsi, Teres major/minor, subscap, infr
Circumduction Combination
Lateral rotation Infraspinatus, teres minor
Medial rotation Subscapularis, teres major, pec major
Stability Poor stability due to: head larger, lax capsule
Bony - Upward displacement prevented by acromion and coracoid processes;
Glenoid labrum; capsule, Ligamentous - Glenohumeral and coracohumeral ligs
Splinting effect tendons long biceps/triceps
Muscular - tendons scapular muscles (rotator cuff) - also TMaj, LD, Pec maj
Proximal Radioulnar Joint
Type: pivot, synovial
Articular Surfaces: radial head / radial notch ulna/annular ligament
Capsule: continuous with elbow
Ligaments:
annular: ant/post radial notch of ulna looping around radius
quadrate: neck radius to supinator fossa ulna
Nerve: pronation → median; supination → musculocutaneous and radial
Artery: radial and middle collateral anastomosing with radial/recurrent interos
Movement: Pronation - Pronator quadratus, Pronator teres; Supination - Biceps, Supinator
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Elbow Joint:
Type: compound synovial, hinge
Communication: superior radio-ulnar joint
Articular Surfaces: trochlea and capitulum of humerus, trochlear notch of ulna,
head of radius
Capsule: continuous with proximal radioulnar joint
Margins articular surfaces capitullum and trochlea; above coronoid and
olecranon fossae; excludes epicondyles
Distally annular ligament, trochlear notch, ant border coronoid process
Ligaments: thickenings of capsule (ie. intrinsic)
radial collateral: lat epicondyle --> annular lig
ulnar collateral (3): med epicondyle --> coronoid process/med olecr
ant - strong; cord-like, med epi to med coronoid
post - weak; fan-like, med epi to med olecranon
oblique – between ant and post
Nerve supply: musculocutaneous, radial, ulnar
Artery: brachial and recurrent branches ulnar and radial
Flexion: biceps, brachialis, brachioradialis, pronator teres, supinator, FDS
Extension: anconeus, triceps
Relations: ant: brachialis, biceps tendon, median nerve, brachial artery
Pronation and supination Axis - Radial head – ulnar styloid – little finger
Distal radioulnar joint
Type: Uniaxial synovial pivot joint
Articulation: Convex head ulna and concave ulnar notch of radius
Triangular fibrocartilaginous disc ulnar notch of radius to fossa base ulnar styloid - divides radiocarpal/inf radio-ulnar
Ligaments: anterior and posterior
Nerve and artery: Ant and post interosseous
Movement: Pronation/supination – 140o
Factoid: does NOT communicate with radio-carpal joint; pronation tightens IO membrane
Wrist Joint
Type: synovial, condyloid
Articular Surfaces: Proximally: distal radius/articular disc; Distally: scaphoid, lunate, triquetral (only in full adduction)
Capsule: proximally to distal radius and ulnar; distally to proximal row carpals
Ligaments:
Ant: palmar radiocarpal lig, palmar ulnocarpal lig
Post: dorsal radiocarpal lig
Lat: radial collateral lig - styloid process radius to scaphoid
Med: ulnar collateral lig - styloid process ulnar to triquetral
Movement:
Flexion (80o) → FCR, FCU, Palmaris longus, FDS, FDP
Extension (60o) → ECRL, ECRB, ECU, Extensor digitorum
Abduction (15o) → FCR, ECRL, ECRB, Assisted by AbPL
Adduction (45o) → FCU, ECU
Circumduction; No rotation
Relations: Ant: flexor tendons, Post: extensor tendons, Lat: Radial artery, Med: Post cutaneous branch ulnar nerve
Nerve: ant/post interosseous, dorsal/deep branches ulnar
Stability: Reasonably stable due to limited range of movement, Mod strong ligaments, muscles that cross joint
Carpal joints
Midcarpal joints Synovial joint between 2 rows carpals - plane
Metacarpophalangeal joints Flexion, extension, abduction, adduction.
Interphalangeal joints Flexion, extension
Thumb – 1st CMC joint
Type Synovial, Saddle condyloid - Trapezium with 1st mc
Ligaments UCL, RCL
Movement abduction, adduction, flexion, extension. 1st mc rotates on axis. Opposition = flexion, abduction, med rotation
MPJ of thumb only flexion and extension
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