IT contains bone,muscle, neurovascular and clinical cases

1. SURGICAL ANATOMY OF THE HAND
MODERATOR
DR.CHERNET (ORTHOPEDICIAN)
By DR.HAILU TIBEBU
• )
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2. OUTLINE OF PRESENTATION
DEFINITION
FUNCTIONS
SKIN
BONY SKELETON AND JOINTS
MUSCLES AND SOFT TISSUES
VESSELS AND NERVES
CLINICAL CORRELATION
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3. DEFNITION
The hand is the region of the upper limb distal to the wrist joint.
It is subdivided into three parts:
 the wrist(containing carpal bones.
 the metacarpus.
 the digits (five fingers including the thumb).
The hand has an anterior surface (palm) and a dorsal surface
(dorsum ) of the hand.
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5. FUNCTIONS
 Hand is both mechanical and sensory tool.
 Humans are endowed with fine control and precision movements
unlike other primates.
 The hand accounts for about 90% of upper limb function:
 The thumb is involved in 40-50% of hand function
 The index finger is involved in about 20% of hand function
 The middle finger, which accounts for about 20% of all hand
function, is the strongest finger, and is important for both precision
and power functions
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6. THE BONY SKELETON
 The distal radius is characterized
by the presence of a
 large dorsal tubercle, which acts
as a pulley for the extensor
pollicis longus
 facet for articulation with the distal
end of the ulna,
 two facets for articulation with two
carpal bones (the scaphoid and lunate).
 styloid process.
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7. Cont..
• The distal end of the ulna is small
and characterized by a rounded
head and the ulnar styloid process.
• The anterolateral and distal part of
the head is covered by articular
cartilage.
• The ulnar styloid process originates
from the dorsomedial aspect of the
ulna and projects distally.
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8. CARPAL BONES
• Proximal row from lateral to medial:
– Scaphoid: boat-shaped with scaphoid tubercle
– Lunate: crescent shape
– Triquetrum: the three-sided
– Pisiform: pea-shaped; lies on palmar surface of triquetrum
• Distal row from lateral to medial:
– Trapezium: irregular four sided ,articulates with metacarpal bone of the thumb
– Trapezoid: the four-sided
– Capitate: has head ; largest
– Hamate: has hooked process (hook of hamate)
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9. CONT..
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10. Articular surfaces
• All carpal bone articulate with each other.
• carpal bones in the distal row articulate with the
metacarpals of the digits.
• Only metacarpal of thumb,move over carpal bone.
• proximal surfaces of the scaphoid and lunate
articulate with the radius to form the wrist joint.
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11. Carpal arch
• Carpal bones do not lie in a flat plane; rather,
they form an arch, whose base is directed
anteriorly.
• The lateral side of this base is formed by
tubercles of the scaphoid and trapezium.
• The medial side is formed by the pisiform and
the hook of the hamate.
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13. The flexor retinaculum
attaches to, and spans the
distance between base to
form anterior wall called
carpal tunnel.
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14. • Free movement of the tendons in the carpal tunnel is
facilitated by synovial sheaths, which surround the
tendons.
• All flexor digitorum profundus and flexor digitorum
superficialis surrounded by a single synovial sheath.
• separate sheath surrounds the tendon of the flexor
pollicis longus.
• The median nerve is anterior to the tendons in the
carpal tunnel.
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15. CARPAL TUNNEL
• Serves as a conduit for the median nerve and nine flexor
tendons,gate way to hand.
• The roof of the tunnel is formed by the flexor retinaculum-
Fibrous band which bridges the anterior concavity of carpus.
• Carpal bones and palmar ligament complex form the base.
• Contents-The four tendons of the flexor digitorum profundus,
the four tendons of the flexor digitorum superficialis, and the
tendon of the flexor pollicis longus and the median nerve.
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16. Carpal Tunnel Syndrome
• Carpal tunnel syndrome is an entrapment syndrome due to
pressure on the median nerve with in the carpal tunnel.
• Etiology
obscure, direct effect of increased pressure on median nerve
Overuse
swelling of the tendons and tendon sheaths (e.g.RA)
cysts arising from the carpal joints.
• pain and pins-and-needles sensations in the distribution of the
median nerve.
• Weakness and loss of muscle bulk of thenar muscles may occur.
• Tinel's sign +ve
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17. Avascular necrosis of the proximal scaphoid
• fracture across the waist of
the scaphoid bone
• common
• In 10% of individuals, the
scaphoid bone blood supply
from the radial artery which
supply the proximal portion
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18. METACARPALS and CARPAL
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19. JOINTS OF WRIST AND HAND
• Wrist joint
formed by distal radius, articular disc
over ulna and scaphoid, lunate &
triquetrum.
– Flexion , Extension ,adduction
&abduct.
– the radial styloid extends further
distally than does the ulnar styloid ,
the hand can be adducted to a
greater degree than it can be
abducted.
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20. The capsule of the wrist
joint is reinforced by
 palmar radiocarpal
 palmar ulnocarpal and
 dorsal radiocarpal
ligaments.
 radial and ulnar
collateral ligaments of
the wrist joint span the
distance between the
styloid processes of the
radius and ulna and the
adjacent carpal bones.
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21. CONT…
CARPAL JOINTS
• The synovial joints between the carpal bones, share a
common articular cavity.
• Gliding type of joints allowing slight side to side
movements
CARPOMETACRPAL JOINTS
• Type: gliding synovial joints, except for CMC joint of
thumb (saddle shaped synovial joint).
• Movements: Flexion ,extension ,abduction and
adduction of CMC joint of 1st digit, the rest allowing
only limited gliding movements.
• Movement of this joints increases medially so
metacarpal V slides to the greatest degree
• can be best observed on the dorsal surface of the hand
as it makes a fist.
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22. CONT..
• METACARPOPHALANGEAL JOINTS
The joints between the distal heads of the
metacarpals and the proximal phalanges of the
digits are condylar joints.
MOVEMENTS which allow flexion, extension,
abduction, adduction, circumduction, and limited
rotation .
The capsule of each joint is reinforced by the palmar
ligament and by medial and lateral collateral
ligaments.
• INTERPHALANGEAL JOINTS
• are hinge joints that allow mainly flexion and
extension. They are reinforced by medial and lateral
collateral ligaments and palmar ligaments.
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23. Deep transverse metacarpal ligament
• 3 thick bands of
connective tissue
• connecting the palmar
ligaments of the
metacarpophalangeal
joints of the fingers to
each other.
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24. SKIN
• Dorsum skin is thin,pliable
• Palmar skin is thick, strongly
atached to underlying fascia
• Most firmly anchored to
deep structure at palmar
crease
• Palmar surface contain high
concentration of sensory n.
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25. • Nails are specialized
skin appendage derived
from epidermis
• 90% nail plate is
produced by germinal
matrix and 10% by
sterile matrix which
adds squamous
component
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26. SOFT TISSUES
• Palmar Aponeurosis
• is a triangular condensation of deep
fascia that covers the palm
• anchored to the skin in distal regions
• The apex is continuous with the
palmaris longus tendon or it is
anchored to the flexor retinaculum.
• Vessels, nerves, and long flexor
tendons lie deep to the palmar
aponeurosis in the palm.
.
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27. • deep spaces of the hand
include
 midpalmar space
• Thenar space
• interdigital web spaces
• less well-defined
• hypothenar space,
• Parona space, and
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28. Anatomical snuffbox
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29. Fibrous digital sheaths
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30. CONT..
Flexor Pulleys
1. annular pulleys position the tendons close to the
underlying bone.
2. Cruciate pulleys are interdigitated between the annular
pulleys and are less critical for function.
Pulleys prevent bowstringing of the flexor tendons during
flexion. There are five annular (A).
• A1—metacarpophalangeal joint;
• A2—proximal portion of the proximal phalanx
• A3—proximal interphalangeal joint
• A4—middle portion of the middle phalanx
• A5—distal interphalangeal joint
• A2 and A4 are essential to prevent bowstringing
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31. nutrition • Tendon nutrition is believed from two basic
sources:
• 1) the synovial fluid produced within the
tenosynovial sheath and
• (2) the blood supply provided through
longitudinal vessels in the paratenon,
intraosseous vessels at the tendon insertion,
and vincular circulation
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32. CONT…
• Extensor Hood
– A complex tendon, formed by
expansions of tendons of extensor
digitorum & extensor pollicis longus
muscles on the dorsal aspect of
proximal phalanges.
– Creates a ‘cable’ system and by
inserting on it the intrinsic muscles of
the hand provide a mechanism for
extending the IPJ while flexing the MCP
joints, allowing the hand to execute
precision movements.
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33. Muscles of the hand
 subdivided into two groups based on their origin:
– Intrinsic muscles- that arise and insert within the hand, and
– Extrinsic muscles -that originate in the forearm and insert within the hand.
• extrinsic muscles function in forcefully gripping ('power grip') with the hand, the
intrinsic muscles mainly execute precision movements ('precision grip') with the
fingers and thumb.
• The extrinsic muscles are again subdivided in to two:
– The flexors, located in the anterior compartment,arise from medial epicondyle
– The extensors, located in the posterior compartment,arise from lateral
epicondyle
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34. EXTRINSIC MUSCLES –
Anterior compartement
• The anterior compartment ms occur in three
layers: superficial, intermediate, and deep.
• Generally, these muscles are associated with:
 movements of the wrist joint;
 flexion of the fingers including the thumb;
 pronation.
Superficial muscles
• Pronator teres-pronation.
• Flexor carpi radialis - Flexes and
abducts the wrist.
• Palmaris longus-flexes wrist.
• Flexor carpi ulnaris - Flexes and
adducts the wrist joint
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35. CONT..
• Anterior Compartment
 Intermediate Muscle
• Flexor Digitorum superficialis
• Insertion middle phalanges of digits 2 - 5
• Action Flexes middle phalanges at proximal
interphalangeal joints also flexes proximal
phalanges at metacarpophalangeal joints of
hand.
• Flex wrist jnt
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36. CONT..
DEEP MUSCLES
• Flexor pollicis longus
 insertion Base of distal phalanx of thumb
 Action Flexes thumb
Flexor digitorum profundus
 Insertion Base of distal phalanx of digits 2 – 5
 Action Flexes MCP, distal and proximal
interphalangeal joints. Flex wrist
Pronator quadratus
 origion-Lower end of ulna
 Insertion-1/4 of anterior surface of distal radius
 Action Pronates forearm;
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37. Cont..
• All muscles in the anterior compartment of the forearm are innervated by the
median nerve, except for the
 flexor carpi ulnaris muscle and the
 medial half of the flexor digitorum profundus muscle, which are innervated by the
ulnar nerve.
• The digital flexors
 flexor digitorum superficialis
 flexor digitorum profundus
 flexor pollicis longus
pass through the carpal tunnel to provide dual flexion to the fingers and single
flexion to the thumb.
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38. POSTERIOR
COMPARTEMENT
• Muscles in the posterior compartment of the
forearm occur in two layers:
1. superficial and
2. deep layer.
The muscles are associated with:
 movement of the wrist joint;
 extension of the fingers and thumb;
 supination.
1)Superficial muscles
• Extensor carpi radialis longus
• Extensor carpi radialis brevis
• Extensor digitorum and Extensor
digiti minimi
• Extensor carpi ulnaris
• Brachioradials
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39. CONT..
– Deep muscles
• Abductor pollicis longus (APL)
• Extensor pollicis brevis (EPB)
• Extensor pollicis longus (EPL)
• Extensor indicis (EI)
• supinator
 All muscles in the posterior
compartment of the forearm are
innervated by the radial nerve.
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40. INTRINSIC MUSCLES OF THE HAND
The intrinsic muscles of the hand are located in five compartments
 Thenar compartment
 Hypothenar compartment
 Adductor compartment
 Central compartment (Lumbricals)
 Interosseous compartment
• All of the intrinsic muscles of the hand are innervated by the deep branch
of the ulnar nerve except for the three thenar and two lateral lumbrical
muscles, which are innervated by the median nerve.
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41. CONT..
THENAR MUSCLES
include
 abductor pollicis brevis-abducts thumb
at MCPJ
 flexor pollicis brevis –flexes thumb at
MCP
 opponens pollicis-largest,medialy
rotates thumb and flex metcarpal 1
 are associated with opposition of the thumb
and with delicate movements of the thumb
 responsible for the thenar eminence on the
lateral side of the palm at the base of the
thumb.
 innervated by the recurrent branch of the
median nerve.
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42. CONT..
• Hypothenar muscles
– abductor digiti minimi- Abducts
little finger at MCPJ
– flexor digiti minimi brevis-
Flexes little finger at MCPJ
– opponens digiti minimi-
Laterally rotates metacarpal V
• The hypothenar muscles are similar
to the thenar muscles in name and
in organization.
• But are innervated by the deep
branch of the ulnar nerve.
• NB. Palmaris Brevis (in
subcutaneous space)
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43. CONT..
Adductor Pollicis
• Origin 2nd and 3rd metacarpals, capitate
• Insertion Medial side of base of proximal
phalanx of thumb
• Action a powerful adductor of the thumb
and opposes the thumb to the rest of the
digits in gripping.
• Innervation-ulnar nerve
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44. CONT..LUMBRICALS
• There are four lumbrical (worm-
like) muscles.
• the medial two lumbricals are
bipennate and lateral two
lumbricals are unipennate ms.
• The medial two are innervated
by the ulnar nerve; the lateral
two are innervated by the
median nerve.
• Flex MCPJ and extend IPJ.
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45. THE INTEROSSEI
• Muscles between and
attached to the
metacarpals.
• Are divided into two
1. the dorsal interossei –
• four bipennate muscles
• most dorsal.
• They are major abductors
of the index, middle, and
ring fingers, at the MCP
joints.
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46. • the palmar interossei.
• anterior to dorsal
interossei
• 4 unipennate ms .
• Adduct the thumb,
index, ring, and little
fingers
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47. ARTERIAL ANATOMY OF THE HAND
• The brachial artery bifurcates at the elbow into radial and ulnar
branches, which are the main arterial branches to the hand.
ULNAR ARTERY
Enters the hand anterior to the flexor retinaculum between the
pisiform and the hook of hamate via the ulnar canal (Guyon canal)
• Lies lateral to the ulnar nerve.
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48. SUPERFICIAL PALMAR
ARCH
• .
• Direct Continuation of
ulnar artery
• Completed on lateral
side by superficial
branch of radial artery.
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49. CONT…
RADIAL ARTERY
• Curves dorsally around lateral side of wrist
and passes over the floor of anatomical
snuff box and enters the palm by passing
between the heads of 1st dorsal
interosseous muscle.
• It then turns medially and passes between
the heads of the adductor pollicis.
• Ends by anastomosing with the deep branch
of the ulnar artery to form the deep palmar
arch.
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50. Cont..
• dorsal carpal branch, which passes
medially as the dorsal carpal arch,
across the wrist and gives rise to
dorsal metacarpal arteries, which
subsequently divide to become
small dorsal digital arteries, which
enter the fingers;
• the first dorsal metacarpal artery,
which supplies adjacent sides of
the index finger and thumb.
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51. DEEP PALMAR ARCH • Direct continuation of radial artery
• Completed on the medial side by
deep branch of ulnar artery
• Deep to long flexor tendons, in
contact with base of metacarpals.
• Gives rise to palmar metacarpal
branches which join common
palmar digital arteries and three
perforating branches that join dorsal
metacarpal arteries from dorsal
carpal arch.
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52. ALLEN’S TEST
• Allen’s test determines if there are any
vascular anomalies between the radial and
ulnar arteries prior to any vascular procedures.
• Occluding both the radial and ulnar vessels
while the patient flexes and extends the
fingers performs the test.
• This creates pallor in palm and digits. Release
of pressure on either radial or ulnar vessel
should allow return of normal color within 2 to
5 seconds.
• only the thumb and lateral side of the index
finger will fill with blood (become red) when
pressure on the radial artery alone is released
and vice versa.
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53. VEINS OF THE HAND
• The dorsal digital veins drain into three
dorsal metacarpal veins, which unite to
form a dorsal venous network
• Superficial to the metacarpus, this
network is prolonged proximally on
the lateral side as the cephalic vein.
• The basilic vein arises from the medial
side of the dorsal venous network.
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54. NERVES
• The nerves in the hand arise from the brachial
plexus.
• The brachial plexus is formed by the union of the
anterior rami of the last four cervical (C5-C8) and
the first thoracic (T1) nerves that constitute the
roots of the plexus.
The hand is supplied by three nerves
 Ulnar(C7-T1)
 median(C5-T1)
 radial nerves(C5-T1)
• All three nerves contribute to cutaneous or
general sensory innervation.
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55. CONT..
• The ulnar nerve innervates all intrinsic
muscles of the hand except for the three
thenar muscles and the two lateral
lumbricals, which are innervated by the
median nerve.
• The radial nerve only innervates skin on the
dorsolateral side of the hand.
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56. ULNAR NERVE • Arises directly from the medial cord of
brachial plexus (C8-T1)
• In cubital fossa ulnar nerve passes through
fibro-osseous tunnel
• As it leaves the canal it lies between the
flexor corpi ulnaris and flexor digitorum
profundus till middle of forearm
• The ulnar nerve enters the hand lateral to
the pisiform and dorsomedially to the ulnar
artery . Immediately distal to the pisiform, it
divides into a deep branch, which is mainly
motor and a superficial branch, which is
mainly sensory.
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57. CONT..
DEEP BRANCH
• passes with the deep branch of the ulnar
artery
• supplies the interossei, adductor pollicis,
and the two medial lumbricals and
hypothenar muscles.
SUPREFICIAL BRANCH
 innervates the palmaris brevis muscle and
continues across the palm to supply skin on
the palmar surface of the little finger and
the medial half of the ring finger.
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58. MEDIAN NERVE • Arises from lateral & medial cords of
brachial plexus
• Contain fibers C5 –T1
• In the arm it descends post. to pectoralis
major muscle, lateral to brachial artery
• The nerve enters forearm between humeral
and ulnar head of pronater teres
• Then runs between fl digitorum superficialis
and fl digitorum profundus, later emerges 5
cm above wrist radial to tendon of palmaris
longus.
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59. CONT…
• Enters the hand through carpal tunnel.
• divides into a recurrent branch and palmar
digital branches.
• The recurrent branch of the median nerve
innervates the three thenar muscles
• The palmar digital nerves innervate skin on
the palmar surfaces of the lateral three and
one-half digits and cutaneous regions over
the dorsal aspects of the distal phalanges
(nailbeds) of the same digits.
• the digital nerves aslo supply the
lateral two lumbrical muscles.
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60. RADIAL NERVE • Arises from the post cords of the brachial
plexus behind 3rd part of axillary artery.
• Neural element of C5 – C8
• At junction of upper and middle 1/3 of arm
deviates dorsolaterally between medial and
long head of triceps lying adjacent to spiral
groove of humerus,where it is commonly
injured in humeral shaft fracture.
• Supplies no hand muscles.
• Branches to superficial and deep branches
at the level of elbow joint.
• Only the superficial part enters the hand.
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61. CONT…
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62. CLINICAL CORRELATIONS
Ulnar nerve injury –ocurs at two sites:the elbow and the wrist:
• at the elbow, the nerve lies posterior to the medial epicondyle;
• at the wrist, the ulnar nerve passes superficial to the flexor retinaculum and lies lateral
to the pisiform bone.
• lesions are characterized by 'clawing' of the hand .
• metacarpophalangeal joints of the fingers are hyperextended and the interphalangeal
joints are flexed because the function of most of the intrinsic muscles of the hand is
lost.
• Clawing is most pronounced in the medial fingers because the function of all intrinsic
muscles of these digits is lost while in the lateral two digits, the lumbricals are
innervated by the median nerve.
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64. CONT…
MEDIAN NERVE INJURY
• lesion at the elbow-resulting in “Hand of
Benediction” or “obstetricians hand”.
• The lumbricals and flexor digitorum
profundus tendons to digits 2 and 3 are
paralysed. This leads to a loss of flexion at
the MCP joint and the DIP joints. If the
patient is asked to make a fist, they will be
able to flex digit 4 and 5 but not digits 2 and
3.
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65. CONT..
RADIAL NERVE INJURY
• The most common radial nerve injury is
damage to the nerve in the radial
groove of the humerus, which produces
a global paralysis of the muscles of the
posterior compartment resulting in
“wrist drop”.
• Radial nerve damage can result from
fracture of the shaft of the humerus as
the radial nerve spirals around in the
radial groove.
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66. REFERENCES
• Gray’s Anatomy, 39th ed, Elsevier
• Frank- h –Netter atlas of anatomy
• Campbell’s operative orthopedic 20th ed
• Schwartz`s principles of surgery, 10th edition
• Internet
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