Osteology of upper extremity

1. OSTEOLOGY UPPER LIMB

2. Scapula (shoulder blade)
• Triangular flat bone on the postero-lateral aspect of the thorax
over-lying 2nd to 7th ribs.It has lateral/axillary border ,
medial/vertebral border (extending from the superior angle to
inferior angle) & superior border (which has a suprascapular
notch transmitting suprascapular nerve; It is covered by superior
transverse scapular ligament thus converting it into suprascapular
foramen above which are suprascapular vessels.
-It has the body with:-Posterior/dorsal surface divided by the spine of
scapula into smaller supraspinous fossa containing supraspinatus
muscle & larger Infraspinous fossa containing infraspinatus
muscle. The spine of scapula extends laterally as the expanded
acromium. The costal surface is concave, from which subscapularis
muscle arise.

3. • Neck of scapula
• Glenoid (head) with shallow glenoid
cavity/fossa .Long head of biceps is attached
to supraglenoid tubercle.Long head of triceps
is attached to infraglenoid tubercle
• Coracoid process projecting from the glenoid
& is palpable anteriorly.
Coracobrachialis,P.minor & short head of
biceps are attached to it.

7. Humerus
• Its small head articulates with the small glenoid cavity
forming unstable shoulder /glenohumeral joint
• Greater tuberosity,lesser tuberosity inter-tubercular
sulcus/bicipital groove containing long head of biceps
tendon.
• Anatomical neck, surgical neck
• Radial spiral groove along which radial nerve
descends.Deltoid tuberosity
• Medial & lateral supracondylar ridges. Medial
&lateral condyles/epicondyles. Olecranon fossa.
• Capitulum, trochlea . Radial &coronoid fossa.

8. Humerus and Scapula: Anterior Views

9. Humerus and Scapula: Posterior View

11. • Fractures of surgical neck with involvement of
tuberosities are very common especially in
elderly.
• Anterior shoulder dislocation are commonest as
the joint is the most unstable
• Fractures of shaft of humerus-Always check for
wrist drop from damage of radial nerve especially
at spiral groove.
• Supracondylar #s are very common especially in
children.

12. Clavicle (collar bone)
• Its primary ossification is membranous without
cartilage stage at 5th -6th week.
• Transmits force from upper limb to axial skeleton.
• As a strut holding the arm free from the trunk.
• Protection of neurovascular bundle as it passes
through ‘cervical-axillary canal’.
• Muscle attachment- P.major, Trapezius,
sternocleidomastoid, deltoid,
subclavius(Subclavian groove)
• Long bone but has no medullary cavity.

13. • Medial 2/3 is rounded & convex forwards for
clearance of neurovascular bundle through ‘cervical-
axillary canal’ from the neck to axilla. The medial
sternal end forms sternoclavicular joint (has a dic)
with the manubrium of the sternum. It also articulates
with 1st costal cartilage.
• The lateral acromial end forms acromialclavicular joint
(has incomplete disc) with acromium of spine of
scapula at the shoulder.
• Coracoclavicular ligaments (conoid &trapezoid)
joining it to coracoid process & conoid &trapezoid
tubercles of clavicle.

14. • Fractures of clavicle are very common at the
junction between middle &lateral 1/3 often from
indirect force.The medial fragment becomes
elevated by sternocleidomastoid. The lateral
fragment sags down from the weight of the arm ,
but also adducted especially by P.Major.
• Acromial-clavicular disruptions are also common
with torn acromial clavicular &coracoclavicular
ligaments >diastasis of the joint.

15. Clavicle

18. Sternoclavicular Joint

21. Radius
• Head- cylindrical.Hollow superior surface to
articlulate with capitullum of humerus.Also
articulates with radial notch of ulna to form
PRUJ for pronation & supination.
• Radial neck which is clasped by annular
ligament.
• Radial tuberosity for attachment of biceps
tendon the most powerful supinator.

22. • Shaft of radius.-Anterior & posterior lines for
attachment of supinator;- Ridge for
attachment of pronator teres.;-Ridge for
interrosseous membrane.
• Lower end:- Ulnar notch of radius for
articulation with radial head at DRUJ.Articular
surface facets for lunate &scaphoid carpal
bones. Radial Styloid process. Dorsal tubercle
of Lister

23. Fractures of shaft of radius
• Pronator teres is attached midway on the radial
shaft; > if the fracture is proximal to its
attachment, the proximal fragment will be
supinated by biceps, & distal fragment will be
pronated by the pronators .> The fracture must
be reduced by supination of distal fragment. If
the fracture is below the attachment of pronator
teres, the proximal fragment will be in neutral
position because the action of pronator teres is
cancelled by biceps ,>the fracture should
immobilised in neutral position.

24. Individual Muscles of Forearm: Rotators of Radius

25. Bones of elbow: Anterior and
Posterior views

26. Bones of elbow: Lateral and medial
views

27. Bones of elbow, in 90° flexion: Lateral
and medial views

28. Elbow: Radiographs

31. • ‘Pulled elbow ‘ may occur in children by
sudden jerk of the radial head inferiorly out of
annular ligament.
• Colles’ fracture very common due to
osteoporosis especially in postmenopausal
women presenting as ‘dinner folk’ deformity

32. Ulna
• Medial &longer.Angled laterally >10-15 degrees of ‘elbow
carrying angle’>15 in women.Tapers distally (opposite to
radius which tapers proximally).*Distally,the ulna does not
articulate directly with the carpus from which it is
separated by ‘triangular fibro-cartilage articular disc’
• Proximal end;-Olecranon process; coronoid process;
trochlear notch (articulating with trochlea of humerus);
radial notch (Articulating with radial head to form PRUJ);
supinator crest &supinator fossa.
• Shaft of ulna:- interrosseous border
• Head of ulna.
• Styloid process of ulna

33. Bones of Forearm

34. clinical
• #s of shaft of radius & ulna in adults need ORIF because if
their normal alignment is not maintained >stiffness of
rotation movements of supination &pronation.
• Montegia # is # of proximal ulna shaft &dislocation of
PRUJ
• Galeazi # is # of distal shaft of radius with dislocation
ofDRUJ
• Olecranon #s need ORIF because of triceps pull of proximal
fragment
• Elbow triangle formed by tip of olecranon &epicondyles of
humerus is equilateral. It is lost in elbow dislocation but
persists in supracondylar #s

36. Carpus
• Consists of 8 bones arranged in a semicircle into distal
&proximal rows, but articulating together at intercarpal
joints & midcarpal joints.The distal row( whose bones
are trapezium , trapezoid , capitate & hamate, form
the diameter of the semicircle articulating with the
metacarpal bases . The proximal row (whose bones are
scaphoid , lunate, triquetral & pisiform) form the
proximal convexity ,with scaphoid &lunate articulating
with distal radius at the wrist joint. A straight
longitudinal line through 3rd MC, capitate & lunate
passes across the wrist joint.The flexor volar surface of
the carpus is concave to accommodate the flexor
tendons(>10) & median nerve at the carpal tunnel .

37. • Scaphoid;-Tuberosity of scaphoid; Waist of scaphoid
can be felt at the anatomical snuffbox where
tenderness may be due to # at waist of scaphoid.The
waist has vascular foramina more numerous distally >in
#s waist of scaphoid AVN may occur of proximal
fragment.
• Lunate semilunar .AVN occassionally
• Capitate(keystone)largest carpal bone
• Trapezium forms 1st trapezial metacarpal saddle joint.
• Hamate.Hook of hamate.
• Pisiform is like sesamoid bone

38. Metacarpus (palm) & phalangese
(Fingers)
• 5 metacarpals; head, neck, shaft ,base
articulating with the bases of proximal phalanges
at MPjoints.1st metacarpal is short &thick.
• The thumb has only two phalanges proximal &
distal articulating at IP joint enabling the thumb
which is shorter & independent mobility across
the palm.The other fingers have got three
phalanges ,proximal, middle &distal articulating
at PIP &DIP joints

42. Carpal Bones

43. Ligaments of Wrist

44. Bones of wrist and hand

45. Wrist and hand: Radiographs