Download ANATOMY OF THE HAND

ANATOMY OF THE HAND
BY
Dr. J . M . Hassanain
 Hand function is an
important feature in
humans over other
primates who lack
fine control and
precision
EMBRYOLOGY OF THE
UPPER LIMB
Limb buds first appear as small
elevations on ventro lateral body
end of fourth week.
Each limb bud :
Mesenchyme derived from
somatic mesoderm which is
covered by a layer of ectoderm
 Distal end of bud form flipper like
limbs.
 Later bones develop and myoblast
aggregate to develop muscle mass .
 Upper limb rotates laterally 90
degrees
 Specific dermatone ( which is skin
area supplied by a single spinal
nerve )
ANATOMY
Bony skeleton
Muscles and soft tissues
Vessels and nerves
BONY SKELETON
 Wrist joint composed of multiple
carpal bone articulating with the
radius proximally and five
metacarpals distally
 Proximal row of carpal bone
(radial to ulnar)
scafoid , lunate , traquetral ,
pisiform
 Distal row
trapezium , trapazoid , capitate ,
hamate
BONES OF THE HAND
5 Metacarpals
Thumb is no. 1
Little finger is no. 5
PHALANGES
 All fingers have 3 phalanges
proximal
middle
distal
 Except thumb has 2
proximal
distal
 Most of tendon in the hand originate
in muscles arising from the forearm
 Flexor on volar aspect of forearm
must arise from common flexor
tendor (medial epicondyle )
Extensors on dorsal aspect of the
forearm arise from common
extensor tender on lateral
epicondyl
 In the hand ulnar side hypo thenar
muscles acting on the little fingers:
 Abductor digitiminimi
 Flexor digitiminimi brevis
 Opponens digitiminimi
 Radial side thenar muscle acting on
the thumb
 Flexor, adductor pollices
 Abductor pollices brevis
 Opponen pollices brevis
Long flexors
fl. digitorum superficialus
fl. digitorum profundus
Act on all the fingers
Intrinsic
Lumbrical
Dorsal
Ventral interrosies
Vascular Supply of Hand
 Radial artery :
 Superficial palmer branch superficial palmer
arch ,which arises above the wrist
 Common palmer digital
 Deep palmer branches
 Deep palmer arch  palmer metacarpal arteries
which joins the common digital
 Ulnar artery  superficial palmer branch joins on
side of pisiform of superficial palmer branch
VENOUS DRAINAGE OF
HAND
 Via : Dorsal digital vein  dorsal
venous arch
 Basillic vein in front of forearm
Peripheral nerve entrapment
There is a disproportion between
volume of the peripheral nerve
and space within the extremity
through which it passes
Applied Anatomy of Ulnar Nerve
Arises directly from the medial
cord of brachial plexus (C8-T1)
Lies between axillary artery
laterally and axillary vein
medially
 At inferior border of subscapularis
muscle nerve receives fiber of C7
( lat. root of ulnar nerve )
 Descend in arm post. to pectoralis
major muscle ( posterio medial to
brachial artery)
8 cm above medial epicondyl
with branch of superior ulnar
collateral artery diverge medially
from brachial artery to pierce
medial intramuscular septum
 Together descend on medial head of
triceps
 Nerve passes in ulner groove dorsal
aspect of medial epicondyl
 It innervates fl. carpi ulnaris 0.5-1
cm above medial epicondyl
Potential points of compression
in the arm
 Ulnar nerve fibers ( medial cord )
1st rib as nerve passes between rib &
clavicle
 8 cm proximal to medial condyl as nerve
pierce intramuscular septum ( arcade of
Struther )
 Hypertrophy of medial head of triceps may
force nerve anteriorly, as triceps contract,
nerve get compressed
Ulnar Nerve at Elbow &Forearm
 In cubital fossa ulnar nerve passes
through fibro-osseous tunnel
 As it leaves the canal it lies between
the flexor corpi ulnanis and flexor
digitorum profundus till middle of
forearm
 In distal 1/3 lies just radial to the
flexor corpi ulnaris
 Straight line drawn from medial
epicondyl to radial margin of
pisiform marks the line of the nerve
Supply of ulnar nerve in forearm
 Muscular branch to fl. Digitorum
profundus ( i.e. ulner ½ ) 3 cm distal
to medial epicondyl
 Palmer cutanous branch
 Dorsal cutanous branch
Ulnar nerve enters hand
 From under fl corpi ulnaris muscle , nerve
and artery
 Radial to pisiform , superficial to transverse
carpel lig. and dorsal to superficial palmer
lig.
 Ulnar nerve divide to :
deep terminal branch
superficial palmer branch
Muscle supplied by ulnar nerve
 Flexor corpi ulnaris
 Flexor digitorum profundus ( medial 2
tendons )
 Flexor digiti minimi
 2 ,3 ,4th web space interossei
 3rd & 4th lumbricle
 Adductor pollicis
 1st dorsal interosseous
Sensory Supply of Ulnar Nerve
 Dorsal cutanous
branch of ulnar :
skin dorsoulnar side of
hand , little finger and
ulnar ½ of index
finger
 Medial cutanous nerve
of forearm : C8-T1
skin over
biceps
elbow crease
Anatomical Sites of Compression
 Points in elbow and forearm
 Anconeus epitrochlearis muscle
 Fibrous arcade between 2 heads of fl.
carpi ulnaris
Site of compression
in hand &wrist
 Palmaris brevus muscle
 Fibrous origin of fl digitiminmi
 Ulnar artery aneurysm or
thrombosis
 Distal ulnar tunnel ganglia
MEDIAN NERVE
 Arises from lateral & medial cords of
brachial plexus
 Contain fibers C5 –T1
 Forms antrolat to 3rd portion of axillary
artery in upper 1/3 of arm
 In the arm it descends post. to pectoralis
major muscle, lateral to brachial artery,
antromedial to brachialis muscle,
posteromedial to biceps
 In mid portion of arm, median nerve crosses
ant to brachial artery to lie on its medial
side to enter the cubital fosse
 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
MEDIAN NERVE IN THE WRIST
 It enters the wrist dorsal to transverse carpal
lig through the carpal tunnel
Boundaries Of Carpal Tunnel
 Dorsally: radio carpal lig.
 Radially: scaphoid & trapezium
 Palmorly: transverse carpal lig.
 Ulnary: hood of hamate & pisiform
After exiting carpal tunnel
 Median nerve splits to two parts
 Common digital nerve to thumb
 Proper digital nerve to radial side of index
 Ulnar division of median nerve; common
digital to 2nd & 3rd web
Muscle supplied by median nerve
 Forearm
 Pronator teres
 Flexor digitorum superficialis
 Flexor carpi radialis
 Palmaris longus
 Flexor digitorum profundus
 Flexor pollicis longus
 Pronator quadratus
HAND
 Flexor pollicis brevis
 Abductor pollicis brevis
 Opponens pollicis
 First lumbrtical
 Second lumbrical
Anatomical compression points of
the median nerve
 ARM:
 Pectoralis minor muscle
 Anomalous axillary arch muscles
 Anomalous vascular arches in the axilla
 Deltopectoral fascia
 Supracondyloid process
 Ligament of Struthers
FOREARM
 Lacertus fibrosus
 Pronator teres muscle
 Flexor digitorum superficialis arch
 Anomalous muscles
 Ulnar collateral or radial artery branches
HAND / WRIST
 Carpal tunnel
 Palmar cutaneous branch within the
transverse retinacular ligament
RADIAL NERVE
 Arises from the post cords of the brachial
plexus behind 3rd part of axillary artery
 Neural element of C5 – C8
 Proximal 1/3 of arm nerve descends behind
brachial artery ant to subscapularis ,teres
major ,latissmus dorsi muscle and long
head of triceps
 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
 10 cm above lat humeral epicondyl lying
between the brachialis and brachioradialis
then lies between brachialis and extensor
carpi radialis ant to tip of lat epicondyl
dividing into : Superficial
Deep branches
Radial Nerve In Forearm
 Superficial branch ant to supinator muscle
proximal 1/3 then deep to brachioradialis
 The sup branch pierces the fascia on the
brachioradialis on the ulnar side of tendons
7cm above wrist
 On the dorsoradial side of wrist it divides
into 5 dorsal digital nerves and only one
branch to extensor carpi radilalis brevus
muscle
 Post interosseous nerve (deep terminal
branch of radial nerve ) innervates extensor
muscle of wrist
 It is seperated from the radium by deep
head of supinator
 After leaving the supinator it lies between
the abductor pollies and other extensors of
forearm
 In distal forearm it penetrates the extensor
pollies brevus to lie in the interosseous
membrane
 Distally it divides to give sensory
innervation to the wrist
Muscles supplied by radial nerve
 Triceps : long head
medial head
lateral head
 Anconeus
 Brachioradialis
 Extensor carpi longus
 Extensor carpi radialis brevis
Muscles supplied by radial nerve
 Extensor carpi ulnaris
 Extensor digitorum communis
 Extensor digiti minimi
 Abductor pollicis longus
 Extensor pollicis longus
 Extensor pollicis brevis
 Extensor indicis proprius
Anatomical compression points of
the radial nerve
 ARM:
 Accessory subscapularis teres latissimus
 Lateral head of the triceps muscle
 Lateral intermuscular septum
 FOREARM:
 Posterior interosseous nerve within radial
tunnel
 Fibrous bands attached to radiocapitelar
joint
 Extensor carpi radialis brevis muscle
 Arcade of Frohse
 Fibrous bands within the supinator muscle
 Superficial radial nerve
 Between brachioradialis muscle & radial
shaft
 Between brachioradialis and extensor carpi
radialis longus tendons
THANK YOU

THE END