Download Anatomy of Hand and Wrist

Anatomy of
Hand and Wrist 4
Assistant professor
Dr. Alaa A. Alharba
Orthopedic &Hand Surgeon
The regions of the Wrist
Anterior aspect of the wrist
The following structures
pass superficial to the
flexor retinaculum from
medial to lateral:
1. Flexor
carpi
ulnaris
tendon ending on the
pisiform bone.
2. Ulnar nerve lies lateral to
the pisiform bone.
3. Ulnar artery lies lateral
to the ulnar nerve.
Structures that pass superficial to the flexor
retinaculum from medial to lateral(continued)
4. Palmar cutaneous
branch of the ulnar
nerve.
5.
Palmaris
longus
tendon
(if
present)
passing to its insertion
into
the
flexor
retinaculum and pamar
aponeurosis.
6. Palmar cutaneous
branch of median nerve.
• The structures passing
beneath the flexor
retinaculum from medial to
lateral:
1. Flexor digitorum superficialis
tendons(FDS).
2. Flexor digitorum profundus
tendons(FDP) passing deeply
to the tendons of FDS. Both
groups of tendons share a
common synovial sheath.
3. Median nerve.
4. Flexor
pollicis
longus
tendon(FPL) surrounded by a
synovial sheath.
5. Flexor
carpi
radialis
tendon(FCR) through a split in
the flexor retinaculm. The
tendon is surrounded by a
synovial sheath.
• v
Posterior aspect of the
Wrist:
the following structures
passing superficial to the
extensor retinaculum from
medial to lateral:
1. Posterior
cutaneous
branch of the ulnar
nerve.
2. Basilic vein.
3. Cephalic vein.
4. Superficial branch of
radial nerve.
•
The
extensor
retinaculum send fibrous
septa
pass
to
the
underlying radius and
ulna
and
form
six
compartments
that
contain the tendons of the
extensor muscles. Each
compartment is provided
with a synovial sheath ,
which extends above and
below the retinaculum.
• Synovial Sheath:
• It is a tubular bursa that
surrounds a tendon. The
tendon invigilates this bursa
from one side so that the
tendon
becomes
suspended within the bursa
by a mesotendon. The
mesotendon enables blood
vessels to enter the tendon
along its course. Synovial
sheath
occur
where
tendons
pass
under
ligaments and retinacula
and through osteofascial
tunnels.
• Function is to reduce friction
between the tendon and the
surrounding structures
Wrist Joint
( Radio Carpal Joint)
• Wrist Joint:
• Articulation between the
distal end of the radius
above (proximal articular
surface) and the scaphoid,
lunate and triquetral bones
below ( distal articular
surface).
• Type: synovial ellipsoid
joint: the proximal articular
surface is concave which is
adapted to the distal convex
surface.
• Capsule: encloses the joint
and is attached above to
the distal ends of the radius
and ulna and below to the
proximal row of the carpal
bones.
•
Wrist joint
• Ligaments: anterior and
posterior ligaments
strengthen the capsule.
The medial ligament
attached to the styloid
process of the ulna and
to the triquetral bone.
Lateral ligament is
attached to the styloid
process of the radius
and to the scaphoid
bone.
Wrist Joint:
• Synovial membrane: it lines the capsule and
attached to the margins of the articular
surfaces. The joint cavity of the wrist joint
does not communicate with the distal
radioulnar joint or with the joint cavities of
the intercarpal joints.
• Nerve Supply: anterior interosseous nerve
and the deep branch of the radial nerve.
• Movements:
• Flexion , Extension, Abduction, Adduction. The
rotation is not possible and compensated by
supination and pronation of the forearm.
 Flexion: performed by FCR, FCU, and Palmaris
longus, assisted by FDP, FDS, and FPL.
 Extension: by ECRL, ECRB, ECU, and assisted
by AbPL, EPL and EPB.
 Abduction: by FCR, ECRL, and ECRB.
 Adduction: by FCU and ECU.
Wrist Joint
• Important Relations:
•
 Anteriorly: the tendons of
FDP, FDS, FPL, FCR, FCU,
and the median and ulnar
nerve.
 Posteriorly: the tendons
of ECU, EDM, ED, EI,
ECRL, ECRB, and AbPL.
 Medially: the posterior
cutaneous branch of the
ulnar nerve.
 Laterally: the anatomic
snuffbox and the radial
artery.
• Anatomic Snuffbox:
• Is a term commonly used
to describe a triangular
skin depression in the
lateral side of the wrist
that is bounded medially
by the tendon of the
extensor pollicis longus
and laterally by the
tendons of the abductor
pollicis
longus
and
extensor pollicis brevis.
Its importance lies in the
fact that scaphoid bone is
most easily palpated here
and that the pulsation of
the radial artery can be
felt here.
• Anatomic Snuffbox:
• Bony
points
readily
palpable in the snuffbox are
the radial styloid proximally
and the base of the thumb
metacarpal distally. between
the two the scaphoid and
trapezium can be felt. In the
floor of the snuffbox the
cutaneous branches of the
radial nerve cross these
tendons. The cephalic vein
begins in the snuffbox from
radial side of the dorsal
venous network( arch). The
radial artery is deep to all
three tendons lies in the
floor.
Surface anatomy of the Wrist Joint:
1. Styloid process of the radius and ulna can be palpated. The
styloid process of the radius lies about (1.9cm) distal to the
styloid process of the ulna.
2. Dorsal tubercle of the radius is palpable on the posterior
surface of the distal end of the radius.
3. The head of the ulna is easily felt with the forearm pronated ,
the round head of the ulna become prominent and
distinguished from more distal pointed styloid process.
4. Pisiform bone can be felt on the medial side of the anterior
aspect of the wrist between the two transverse creases.
5. The hook of the hamate felt on deep palpation of the
hypothenar eminence ( distal and lateral to the pisiform bone).
6. The proximal transverse crease lies at the level of the wrist
joint, while the distal transverse wrist crease lies corresponds
to the proximal border of the flexor retinaculum.