Upper Extremity Osteology

Front 1

Superior Angle

Back 1

• Connection between the superior and medial borders of the scapular
• Part of distal attachment for levator Scapulae
• Part of distal attachment for rhomboid minor
  

Front 2

Inferior Angle

Back 2

• Connection between the medial and lateral border of the scapula
• Deep to superior border of latissimus dorsi (sometimes attaches there)
  
• Proximal attachment for teres major
• Can become pronounced (along with medial border) with paralysis of serratus anterior usually due to long thoracic nerve injury
  

Front 3

Glenoid Cavity/ Fossa

Back 3

• Located on the lateral surface of the scapula
• Receives and articulates with the head of the humerus
• Shallow, concave, oval fossa
• Directed anteriorlaterally and slightly superiorly
• Considerable smaller than the head of the humerus
  

Front 4

Vertebral (Medial) Border

Back 4

• Thin medial border of scapula
• Runs parallel, and approximately 5cm lateral to the spinous process of the thoracic vertebrae
• Superior portion of border is a distal attachment for levator scapulae
• Distal attachment for rhomboids from root of spine to inferior angle
• Costal surface is a distal attachment for serratus anterior
  

Front 5

Axillary (Lateral Border)

Back 5

• Thickest border of scapula
• Runs towards the apex of the axilla
• Thickness prevents buckling of this stress bearing region of the scapula
• Upper 2/3 is the proximal attachment for teres minor
  

Front 6

Superior Border of the Scapula

Back 6

• Contains suprascapular notch (located where the superior border joins the base of the coracoid process)
  
• Anteriorly forms the coracoid process
• Thinnest and shortest border of the scapula
  

Front 7

Acromion

Back 7

• Distal end of spine of scapula
• Articulates with the clavicle as the AC joint
• Distal attachement for superior and medial fibers of trapezius
• Proximal attachment for deltoid
  

Front 8

Supraspinous Fossa

Back 8

• Upper surface of the posterior scapular demarcated on the lower border by the spine of the scapula
  
• Proximal attachment for supraspinatus
  

Front 9

Infraspinous Fossa

Back 9

• Lower and larger posterior surface of the scapula, inferior to the spine
• Proximal attachment for infraspinatus
  

Front 10

Subscapular Fossa

Back 10

• Concave costal surface of the scapula
• Proximal attachment for subsapularis
  

Front 11

Supraglenoid Tubercle

Back 11

• Area of the scapula superior to the glenoid fossa on the lateral border
• Proximal attachment for long head of biceps brachii
  

Front 12

Infraglenoid Tubercle

Back 12

• Area of the scapula inferior to the glenoid fossa on the lateral border
• Proximal attachment of the long head of the triceps
  

Front 13

Coracoid Process

Back 13

• 'Crow's beak'
• Superior to the glenoid cavity
• Projects anterolaterally
• Medial border and superior surface serves as distal attachment for pec minor
• Tip of process is proximal attachment for short head of biceps brachii
• Proximal attachment of corocobrachialis
  

Front 14

Scapular Notch

Back 14

• Located where the superior border joins the base of the coracoid process
  

Front 15

Neck of Scapula

Back 15

• Shallow area between the head and the body of the scapula
  

Front 16

Acromial End of Clavicle

Back 16

• Flattened lateral end of clavicle
• Articulates with the acromion of the scapula
• Attachment for trapezius on posterior surface of lateral 1/3 of clavicle
• Attachment on anterior surface of lateral 1/3 of clavicle for deltoid
• Inferior surface of middle third of clavicle is a distal attachment of subclavius
  

Front 17

Sternal End of Clavicle

Back 17

• Enlarged, triangular medial end of scapula
• Articulates with the manubrium of the sternum at the SC joint
• Anterior medial half of clavicle is a proximal attachment for pec major
  

Front 18

Anterior Border of Clavicle

Back 18

• Curves anteriorly on the medial end (protrudes near the sternum), curves posteriorly on the distal end until it rounds out as the acromial end
  

Front 19

Trapezoid Line/Ridge of Clavicle

Back 19

• Near the acromial end of the clavicle
• Attachment for the trapezoid ligament (lateral part of the coracoclavicular ligament)
• Inferior surface of clavicle
  

Front 20

Conoid Tubercle

Back 20

• Acromial end of clavicle, medial to trapezoid line on inferior surface
  
• Attachment for conoid ligament
  

Front 21

Costal Tuberosity

Back 21

• Also called impression for the costoclaviuclar ligament
• Rough, often depressed oval area that gives to the ligament binding the first rib to the clavicle
• On inferior surface of clavicle near the sternal end
  

Front 22

Manubrium

Back 22

• 'Handle of a sword'
• Roughly trapezoid bone
• Widest and thickest part of the sternum

Front 23

Body of Sternum

Back 23

• Long, narrow, and thinner than manubrium
• Inferior to manubrium
• Located at the level of T5-T9
• Bordered by costal notches
• Originally sternebra, fuse during puberty through age 25, results in three distinct transverse ridges
• Anterior surface is a proximal attachment for pec major
  

Front 24

Xiphoid Process

Back 24

• Smallest and most variable part of the sternum
• Thin and elongated
• Inferior end lies at the level of T10 vertebrae
• Often pointed
• More or less ossified in adults above 40, in old age may fuse with the sternal body
  

Front 25

Rib Facets

Back 25

• Also called costal notches (7 total)
• First facet is inferior/lateral to clavicular notch
• 1 and 1/2 of 2 located on manubrium
• 1/2 of 2 through 1/2 of 7 located on sternal body
• 1/2 of 7 located inferior to xiphoid joint
• Junction of first cartilage is the proximal attachment for subclavius
  

Front 26

Sternal Angle

Back 26

• Divides manubrium from sternal body
• Formed by the projecting angle of the manubriosternal joint
  

Front 27

Head of Humerus

Back 27

• Articulates with the glenoid cavity of the scapula

Front 28

Anatomical Neck of Humerus

Back 28

• Formed by the groove circumscribing the head and separating if from the greater and lesser tubercles
• Indicates the line of attachment of the glenohumeral joint capsule

Front 29

Surgical Neck of Humerus

Back 29

• Common site of fracture
• Narrow part of the humerus distal to the head and the tubercules
  

Front 30

Greater Tubercle of Humerus

Back 30

• Lateral margin of the humerus
• Superior facet of greater tubercle is distal attachment for supraspinatus
• Middle facet is distal attachment for infraspinatus
• Lower facet is distal attachment for teres minor
  

Front 31

Lesser Tubercle of Humerus

Back 31

• Projects anteriorly from the humerus
• Medial to the greater tubercle
• Distal attachment for subscapularis
  

Front 32

Intertubercular (Bicipital) Groove

Back 32

• Separates the greater and lesser tubercles of the humerus
• Provides protected passage for the slender tendon of the long head of the biceps muscle
• Distal attachment for teres major
• Lateral lip serves as distal attachment for pec major
  

Front 33

Deltoid Tuberosity

Back 33

• Lateral shaft of humerus (lines up inferior to greater tubercle
• Superior to radial groove
  
• Attachment for deltoid muscle

Front 34

Lateral Epicondyle of Humerus

Back 34

• Lateral projection of distal humerus
• Muscle attachment for common extensors tendon
• Proximal attachment for ECRB, ED, EDM, ECU
• Proximal attachment for supinator
• Posterior aspect is the proximal attachment of anconeus
  

Front 35

Medial Epicodyle of Humerus

Back 35

• Medial projection of distal humerus
• Muscle attachment for flexors (PT, FCR, PL, FCU)
• Part of proximal attachment of FDS

Front 36

Lateral Supracondylar Ridge of Humerus

Back 36

• Lateral widening of the humerus
• Superior to lateral epicondyle
• Proximal attachment of brachioradialis
• Part of proximal attachment for ECRL
  

Front 37

Medial Supracondylar Ridge of Humerus

Back 37

• Medial widening of the humerus
• Superior to the medial epicondyle
• Proximal attachment of pronator teres
  

Front 38

Capitulum

Back 38

• Lateral articular surface of the humerus
• Articulates with the head of the radius
• Lateral part of the condyle of the humerus
  

Front 39

Trochlea

Back 39

• Medial articular surface of the humerus
• Articulates with the proximal end (trochlear notch) of the ulna
• Medial part of the condule of the humerus
  

Front 40

Radial Groove

Back 40

• Oblique/ spiral groove on posterior side of humerus
• Inferior to deltoid tuberosity
• Passage for radial nerve and profunda brachii artery
• Distal to proximal attachment of lateral head of triceps
• Proximal to distal attachment of medial head of tricpes
  

Front 41

Olecranon Fossa

Back 41

• Posterior fossa of the distal humerus
• Accommodates the olecranon of the ulna in full elbow extension
  

Front 42

Coronoid Fossa

Back 42

• Anterior, medial, and distal fossa of the humerus
• Superior to the trochlea
• Receives the coronoid process of the ulna during full flexion of the elbow
  

Front 43

Radial Fossa

Back 43

• Superior to the capitulum anteriorly
• Accommodates the edge of the head of the radius when the forearm is fully flexed
  

Front 44

Olecranon

Back 44

• Projects proximally from the posterior aspect of the ulna
• Forms the point of the elbow
• Serves as a short lever for extension of the elbow
• Articulates with the humerus at the trochlea/ olecranon fossa
• Proximal attachment of FCU
• Distal attachment of triceps brachii and anconeus
  

Front 45

Trochlear Notch

Back 45

• Formed by the walls of the olecranon and coronoid process of the ulna
  

Front 46

Coronoid Process

Back 46

• Anterior projection of the ulna
• Distal attachment of brachialis
  
• Proximal attachment of pronator teres
• Proximal attachment of FDS
  

Front 47

Ulnar Tuberosity

Back 47

• Inferior to the coronoid process of the ulna
• Attachment for the tendon of the brachialis muscle
• Distal attachment of brachialis
  

Front 48

Radial Notch

Back 48

• smooth, rounded, concavity on the lateral side of the coronoid process
• Receives the broad periphery of the head of the radius

Front 49

Head and Styloid Process of Ulna

Back 49

• Distal end of ulna
• Small, conical, medial process
• End of ulna (which does not reach the wrist)
  

Front 50

Ulnar notch of Radius

Back 50

• Concavity on medial aspect of radius
• Accommodates the head of the ulna
  

Front 51

Interosseous Membrane

Back 51

• Part of proximal attachment for FDP, FPL, APL, EPB, EPL,EI

Front 52

Dorsal (Lister's) Tubercle

Back 52

• Pulley for the tendon of EPL
• Palpable on the dorsal side of the wrist
• Prominence on distal radius
  

Front 53

Scaphoid (navicular)

Back 53

• Part of proximal attachment for abductor pollicis brevis, flexor pollicis brevis, opponens pollicis
• Articulates proximally with the radius
  

Front 54

Lunate

Back 54

• Moon shaped bone between scaphoid and triquetral
  

Front 55

Triquetrum

Back 55

• Pyramidal bone on the medial side of the carpus
• Articulates with articular disc of radio-ulnar joint
  

Front 56

Pisiform

Back 56

• Distal attachment of FCU
• Part of proximal attachment of abductor digiti minimi
• Lies on palmar surface of triquetrum
  

Front 57

Trapezium

Back 57

• Four sided bone on the lateral side of the carpus
• Articulates with the 1st and 2nd metacarpals, scaphoid, and trapezoid
  

Front 58

Trapezoid

Back 58

• Wedge shaped bone that resembles trapezium
• Articulates with 2nd metacarpal, trapezium, capitate, and scaphoid
  

Front 59

Capitate

Back 59

• Part of the proximal attachment of the oblique head of adductor pollicis
• Head shaped bone with rounded extremity
• Largest bone of the carpus
• Articulates with the 3rd metacarpla, trapezoid, scaphoid, lunate, and hamate
  

Front 60

Hamate

Back 60

• Hook is distal attachment for FCU
• Part of proximal attachment of flexor digiti minimi brevis and opponens digiti minimi
• Wedge shaped bone on the medial side of hand
  
• Articulates with 4th and 5th metacarpal, ctate, triquetral
• Has distinct hooked process
  

Front 61

Metacarpals

Back 61

• Base of 2nd metacarpal is distal attachment for FCR
• Dorsal base of 2nd metacarpal is the distal attachment for ECRL
• Dorsal base of 3rd metacarpal is the distal attachment for ECRB
  
• Oblique head of AP attaches on the bases of the 2nd and 3rd metacarplas
• Transverse head of AP attaches on the shaft of the 3rd metacarpal
• Adjacent sides of the metacarpals are the proximal attachments of the dorsal interossei
• Palmar surfaces of the metacarpals are the proximal attachments of the palmer interossei
  

Front 62

Phalanges

Back 62

• FDS has a distal attachment on both sides of the middle phalynx, digits 2,3,4,5
• FDP has distal attachments on the base distal phalanges on all 4 fingers
• EI has a distal attachment at the base of the dorsal, proximal, 2nd phalanx
• Dorsal and palmer interossei attach distally at the bases of the proximal phalanges
  

Front 63

Head of Radius

Back 63

• Proximal end of radius
• Smooth superior aspect of radius
• Articulates with the capitulum of the humerus
• Articulates with the radial notch of the ulna
• Covered in articular cartilage
  

Front 64

Radial (Bicipital) Tuberosity

Back 64

• Distal attachment for biceps brachii

Front 65

Spine of Scapula

Back 65

• Ridge on posterior surface of scapula
• Merges with acromion distally
• Distal attachment for middle and lower fibers of trapezius
• Proximal attachment for deltoid
  

Front 66

Styloid Process of Radius

Back 66

• Located on the distal radius
• Located distal to distal attachment for brachioradialis
• Much larger than the styloid process of the ulna
  

Front 67

Phalanx of the Little Finger

Back 67

• Medial side of base of the proximal phalanx of the little finger is the distal attachment of abductor digiti minimi and flexor digiti minimi brevis
  

Front 68

Phalanx of the Thumb

Back 68

• FPL has distal attachments on the base of the phalanx of the thumb
• EPB has a distal attachment at the base of the proximal phalanx of the thumb
• EPL has a distal attachment at the base of the distal phalanx of the thumb
• APB and FPB attaches on the radial side of base of the proximal phalanx of the thumb
• AP attaches distally on the ulnar side of the proximal phalanx of the thumb
  

Front 69

Metacarpal of the Little Finger

Back 69

• 5th metacarpal is distal attachment for FCU
• Base of 5th metacarpal is the distal attachment of ECU
• Ulnar side of the 5th metacarpal is the distal attachment of opponens digiti minimi
  

Front 70

Metacarpal of the Thumb

Back 70

• Base of 1st metacarpal is the distal attachment for APL
• Radial anterior side of shaft of the 1st metacarpal is the distal attachment of opponens pollicis