Upper limb Flashcards
(13 cards)
Carpal bones (including ossification)
The carpal bones are the eight bones of the wrist. They form the articulation between the forearm
and the hand.
Gross anatomy:
Unlike the metacarpals the carpals do not belong to individual fingers
The corresponding bones in the foot at the tarsals
Divided in 2 rows proximal and distal
Proximal:
- Scaphoid
- Lunate
- Triquetrum
- Pisiform (actually a sesamoid bone with the flexor carpi ulnaris tendon)
Distal:
- Trapezium
- Trapezoid
- Capitate
- Hamate
Mnemonic: Some lover’s try positions that they can’t handle
Articulations: All synovial
- Radiocarpal
- Intercarpal
- Carpometacarpal
Ligaments:
- Ulnar and radial collateral ligaments
- Palmar and dorsal radiocarpal ligaments
- Palmar and dorsal carpometacarpal ligaments
- Intercarpal ligaments
Ossification:
Start at the capitate move around anti-clockwise, skip the pisiform
- Capitate 1m
- Hamate 2m
- Triquetrium 3y
- Lunate 4y
- Scaphoid 5y
- Trapezium 6y
- Trapezoid 7y
- Pisiform 8y
Arterial:
- Dorsal carpal arch, deep palmer arch, direct radial, and ulnar branches
Venous:
- Dorsal venous plexus, deep palmer venous arch, direction radial and ulnar veins
Variants:
- Carpal coalition
- Bipartate scaphoid
- Type 1 or type 2 lunate
Lunate
The lunate is a bone of the proximal row of carpal bones
Location: between the scaphoid and triquetrum in the proximal carpal row
Osteology:
- Semi-lunar in shape
- 4 articular facets (five in type 2)
Articulations:
- Radius
- Scaphoid
- Triquetrum
- Capitate
- Hamate (in type 2 lunate)
- Triangular fibrocartilage complex
Attachments:
Musculotendonous – nil
Ligaments:
- Scapholunate
- Lunotriquetral
- Radiolunotriquetral
- Radioscapholunate
- Ulnolunate
Blood supply:
- Dorsal radiocarpal arch and dorsal intercarpal arch
Venous:
- Dorsal venous plexus
Variants:
- Lunotriquetral coalition
- Os epilunatum
- Os hypolunatum
- Type 1 lunate – single distal articular facet for the capitate
- Type 2 lunate – additional distal articular facet for the hamate
Scaphoid
The scaphoid is a carpal bone
Location: Most lateral bone of the proximal carpal row
Relations:
- Lateral/dorsal: radial artery
- Medial: lunate and the carpal tunnel
- Distal: Trapezium
- Proximal: distal head of the radius
- Forms the radial portion of the carpal tunnel
Osteology:
- Largest of the proximal row of carpal bones
- Boat shaped
- Dividable into proximal and distal poles, separated by a waist which is further dividable into proximal and distal waists
- Scaphoid tubercle is a bony prominence on the ventral surface serves as an attachment for the flexor retinaculum
Articulations:
- Medial: Lunate
- Proximal: Radius
- Distal:
- Trapezium
- Trapizoid
- Medially with the capitate
Ligaments:
- Scapholunate
- Radioscapholunate
- Dorsal: Dorsal radiocarpal ligament
- Radial surface: radial collateral ligament
Blood supply:
- Direct branches from the radial artery
- Dorsal radiocarpal arch
- Supply enters the distal pole to perfuse the proximal pole (risk of osteonecrosis with waist fracture)
- Venous drainage vie the dorsal venous plexus and the radial veins
Ossification:
- 5 years old
Variants:
- Bipartite scaphoid
- Carpal coalition
- Scaphoid hypoplasia
Radius
The radius is one of the two long bones of the forearm.
Location: Lateral in the forearm, extending from the elbow to the wrist
Osteology:
Components:
- Proximal: Head, neck and tuberosity insertion of the biceps brachii tendon
- Mid: Shaft – thicker that the ulnar and becoming more thick distally
- Distal: Carpal articular facet, ulnar notch, radial styloid, Lister’s tubercle (Dorsal)
Articulations (articular surfaces are synovial):
Proximal:
- Radial head with the capitulum of the humerus
- Radial head with the radial notch of the ulnar
Distal:
- Distal radius facet with the scaphoid and lunate
- Ulnar notch with the ulnar head
Ligaments:
- Radial collateral ligaments of the elbow and wrist
- Radial annular ligament
- Interosseous membrane of the forearm
- Radial carpal ligaments (dorsal and palmar)
- Radioulnar ligaments (dorsal and palmer)
Blood supply:
- Radial artery and vein
Lymphatics:
- Supratrochlear
- Axillary
Innervation:
- Anterior and posterior interosseous nerves
Variants:
- Radio-ulnar synostosis
- Hypoplastic or absent radius
Ulna
The ulna is one of the two long bones of the forearm.
Location: medially with in the forearm
Gross anatomy:
Wider toward the proximal end
Features:
- Proximal: Olecranon, trochlear notch, coronoid process, radial notch, sublime tubercle (medial), (flexor digitorum), ulnar tuberosity (brachialis)
- Mid: Shaft
- Distal: head, styloid process, fovea, groove for extensor carpi ulnaris
Articulations: (all synovial)
- Trochlear notch with the trochlear of the humerus
- Radial head with the radial notch
- Ulnar head with the ulnar notch (radius)
- Wrist via the triangular fibrocartilage complex
Ligaments:
- Proximal: medial collateral ligament of the elbow, annular ligament
- Medial: interosseous membrane, oblique cord
- Distal: triangular fibrocartilage complex, ulnar collateral ligament of the wrist
Blood supply:
Ulnar and common interosseous artery
Lymphatics:
Supratrochlear
Axillary
- Innervation:
Anterior and posterior interosseous nerves
- Variants:
Ulnar variance (relative length difference between the radius and ulnar)
Humerus
Single long bone of the arm
- *Location:** between the shoulder and the elbow
- *Gross anatomy:**
- *Features:**
- Proximal: Rounded head covered with articular cartilage, greater and lesser tubercles, intertubercular groove
- Mid: Surgical neck inferior to the tubercles, deltoid tuberosity, spiral groove from radial nerve
- Distal: condyle of the humerus which consists of: capitulum, trochlear, medial and lateral epicondyles, radial fossa, olecranon fossa, coronoid fossa
Articulations:
- Proximal: the head of the humerus articulates with the glenoid of the scapula
- Distal: capitulum with the radial head, trochlear with the trochlear notch of the ulnar
Ligaments:
- Superior, middle, inferior and spiral glenohumeral ligaments
- Radial and ulnar collateral ligaments
Relations:
- Anterior: brachialis, bicep brachii, coracobrachialis
- Posterior: Profunda brachii, radial nerve, triceps brachii
- Lateral: deltoid
- Medial: brachial plexus, brachial artery, supratrochlear nodes
Blood supply:
- Anterior and posterior humeral circumflex arteries and veins
- Perforators from profunda brachii
Lymphatics:
- Supratrochlear and axillary nodes
Innervation:
- Radial nerve
Variants:
- Supracondylar process
- Olecranon foramen
Scapula
The scapulae are bones of the pectoral girdle.
Location: Superior/posterior thoracic wall
Function: Movement and support of the shoulder girdle and shoulder
Gross anatomy:
The scapula is a flat triangular bone with apex down.
Features:
- Inferior, lateral and superior angles
- Superior, medial and lateral borders
- Posteriorly the scapula is divided into a supraspinatus and infraspinatus fossa by the scapular spine
- Anteriorly there is the subscapular fossa
- Laterally is the glenoid fossa
- Superiorly is the acromion and coracoid process
Articulations:
- Acromion with the distal clavicular head
- glenoid with the humeral head
Ligaments:
- Transverse scapula ligament across the scapular notch (with the suprascapular nerve below and the vessels above)
- Coracoacromial
- Coracoclavicular
- Coracohumeral
- Glenohumeral superior, middle and inferior
- Acromioclavicular
Blood supply:
Anastomotic network formed by:
- Suprascapular
- Dorsal scapular
- Subscapular
Lymphatics:
- Axillary
Muscles:
- Rotator cuff + terres major
- Long head of the triceps and biceps
Variants:
- Os acrominale
Clavicle
The clavicle is the only bone connecting the pectoral girdle to the axial skeleton. It is also the only horizontal long bone.
Gross anatomy:
S-shaped
Features:
- Medial:
- Rounded medial end
- Costal tuberosity
- Groove for subclavius
- Distal:
- Conoid tubercle
- Flat distal end
- Trapezoid line
Articulations:
- Medial end with the sternum
- Distal end with the acromion
Muscles:
- Subclavius
- Pec. Major
- Sternocleidomastoid
- Deltoid
- Trapezius
- Sternohyoid
Ligaments:
- Acromioclavicular
- Coracoclavicular (conoid and trapezoid)
- Sternoclavicular
- Costoclavicular
- Interclavicular
Blood supply:
- Suprascapular artery
Variants:
- Forked clavicle
- Supraclavicular foramen
Wrist joint
The wrist joint is a complex synovial joint
Location: between the forearm and the hand
Movements: flexion, extension, ulnar deviation, radial deviation, circumduction
Gross anatomy:
Made up of the articulations between:
- The distal radius head and ulnar notch
- The ulnar and the triangular fibrocartilage complex (TFCC)
- The radius and the scaphoid, lunate and triquetrum (condyloid joint)
- The TFCC and the triquetrial bone
Special features:
Triangular fibrocartilage complex is a triangular cartilage disc between the ulnar and the triquetral bone
Ligaments:
- Ulnar collateral
- Radial collateral
- Radiocarpal ligaments (palmer and dorsal)
- Flexor and extensor retinacula
- Radioulnar ligaments dorsal and palmer
Muscles:
- Flexor:
- Flexor carpi radialis and ulnaris
- Palmaris longus
- Flexor digitorium superficialis
- Flexor digitorium profundus
- Extensors:
- Extensor carpi radialis longus and brevis
- Extensor carpi ulnaris
- Extensor digitorium
Blood supply:
- Radial and ulnar arteries
Innervation:
- Anterior and posterior interosseous nerves
Variants:
- Absent palmaris longus
- Ulnar variance
Distal radio-ulnar joint
The distal radio-ulnar joint is a pivot joint between the distal radius and ulna
- *Movement:** rotation of the distal radius
- *Gross anatomy:**
- Synovial joint between the ulnar notch on the radius and the ulna head
- The joint in stabilised by the TFCC
Muscles:
- Pronation: pronator quadratus and pronator teres
- Supination: supinator and biceps brachii
Ligaments:
- Anterior and posterior distal radioulnar ligaments
- Interosseous membrane
Blood supply:
- Anterior and posterior interosseous
Innervation:
- Anterior and posterior interosseous nerves
Variants:
- Radial ulna length variance
Glenohumeral joint
The shoulder joint also known as the gleno-humeral joint is a ball and socket synovial joint between the humerus and the glenoid.
Movements:
- Most mobile joint in the body
- Flex/extension, int. ext. rotation, ab and adduction
Articulation:
Head of the humerus with the glenoid fossa of the scapula. The glenoid labrum adds depth to the
glenoid fossa.
Capsule:
- Attached to the margin of the glenoid fossa to the anatomical neck of the humerus, the long head of the biceps travels through it.
- It is re-enforced by the rotator cuff except inferiorly where it is at its weakest
Bursa:
- Subacrominal – subdeltoid bursa
- Subscapular bursa (communicates with the joint by the foramen of Weitbrecht)
Ligaments:
- Superior, middle and inferior glenohumeral ligaments
- Coracohumeral ligaments
- Transverse humeral ligament
Muscles:
- Rotator cuff
- Triceps
- Biceps
- Deltoid
- Many more
Arterial supply:
- Anterior and posterior humeral circumflex and subscapular arteries
Innervation:
- Axially (C5-C6), suprascapular, subscapular, musculocutaneous nerves
Lymphatics:
- Axillary
Variants:
- Buford complex – cord like middle glenohumeral ligament
- Os acrominale
- Capsule attached to labrum
- Long head of biceps insertion – glenoid, glenoid and labrum, labrum only
Acromioclavicular
The acromioclavicular (AC) joint is a plane synovial joint of the pectoral girdle. **Gross anatomy:**
- Between the facets of the convex distal clavicle and flat medial acromion.
- The articular surfaces are lined with hyaline cartilage.
- A fibrocartilaginous wedge-shaped articular disc separates the two articular surfaces.
- A weak, synovium-lined joint capsule is attached to the articular margins and is reinforced superiorly by blending fibres of the trapezius muscle.
Ligaments
Static stabilisation is provided by:
- coracoclavicular ligaments
- superior and inferior acromioclavicular ligaments
Blood supply
- Suprascapular and thoracoacromial arteries
Innervation
- Axillary, suprascapular and lateral pectoral nerves
Variant anatomy
- Acromioclavicular joint configuration
- Os acromiale
Sternoclavicular joint
The sternoclavicular joint is a synovial joint between the medial clavicle, manubrium and the first
costal cartilage that joins the upper limb with the axial skeleton.
Gross anatomy
- Saddle joint between the medial clavicle and the clavicular notch of the sternum
- The articular surfaces are covered with fibrocartilage (rather than hyaline cartilage as in most other synovial joints). The joint space is divided into two separate recesses by a fibrocartilage articular disc.
Ligament
Due to the non-congruent articular facets, much of the joint stability comes from surrounding ligaments:
- anterior and posterior sternoclavicular ligament
- interclavicular ligament
- costoclavicular ligament
Relations
- Anteriorly: sternocleidomastoid muscle
- Posteriorly: sternohyoid muscle, sternothyroid muscle, brachiocephalic veins, the origin of the great vessels
Blood supply
Arterial supply: internal thoracic and suprascapular arteries
Innervation
Medial supraclavicular and subclavian nerves
Variant anatomy
- ~2.5% of the population have an inferior facet for articulation with the first rib
- perforation of the articular disc, where the joint recesses are in communication
