Clinical Anatomy of the Wrist & Hand Flashcards
Wrist Joint
Synovial joint between the distal end of the radius and ulna with the carpal bones • Radius articulate with scaphoid and lunate • Radioulnar disc articulate with lunate and triquetrum
Wrist Joint
-movement
Flexion and extension • Abduction (lateral deviation) and
adduction (medial deviation)
Intercarpal joints
Synovial joints shared a single capsule • Limited movements, but contributes to
the positioning of the hand in flexion,
extension, abduction and flexion
Bones of the wrist-Proximal Row – lateral to medial
- Scaphoid
- Lunate
- Triquetrum
- Pisiform (pea shaped)
Bones of the wrist-Distal Row - lateral to medial
- Trapezium
- Trapezoid
- Capitate: articulate
- Hamate
• hook on palmar surface*
1
st carpometacarpal (CMC) joint
between trapezium and base of
thumb
addle joint which permits
flexion, extension, abduction,
adduction and opposition of thumb
2
nd to 5th carpometacarpal
(CMC)joints
only permits limited
gliding movements
Metacarpophalangeal (MCP) joints
permits flexion, extension,
abduction and adduction of digits
Interphalangeal (IP) joints
permits flexion and extension
Anatomical Snuff Box
A triangular depression formed on
the posterolateral side of the wrist
Anatomical Snuff Box-Lateral borde
- abductor pollicis longus
* extensor pollicis brevis.
Anatomical Snuff Box-Medial border:
extensor pollicis longus.
Anatomical Snuff Box-• Roof:
Superficial branch of the radial nerve
• cephalic vein.
Anatomical Snuff Box- Floor:
Scaphoid and trapezium,
• Distal ends of the tendons of ECRL &
ECRB.
Anatomical Snuff Box-Contents
radial artery.
Clinical Correlate- pain in the “anatomical snuffbox-Where is the fracture?
Scaphoid fracture
What can be the clinical consequences of
delaying treatment of the scaphoid fracture?
Nonunion, avascular necrosis of proximal
portion
Clinical Correlate – Boxers
Fracture
Impaction fracture of the neck fifth metacarpal (sometimes can involve the fourth metacarpal) • Usually comminuted • Usually because of a direct blow with a clenched fist against a solid surface.
Colle’s:
fracture of the
distal radius with posterior
displacement of the distal
fragment
Smith’s
fracture of the
distal radius with anterior
displacement of the distal
fragment
Scaphoid fracture:
usually
around the neck. May lead
to avascular necrosis of
the proximal fragmen
Carpal Tunnel
The carpal tunnel is formed anteriorly at the wrist • Floor: Deep arch formed by the carpal bones • Roof: Flexor retinaculum • Contents: The tendons of FDS, FDP, FPL, and the median nerve
Guyon’s Canal
• Roof: palmar carpal ligament • Floor: flexor retinaculum and hypothenar muscles • Contents: ulnar nerve artery and vein
Compartments of the hand-Midpalmar (central)
Contains long flexor
tendons, lumbricals,
palmar arches
Compartments of the hand-Thenar eminence
Contains FPL tendon and
three thumb muscles
Recurrent median nerve
Compartments of the hand-Hypothenar eminence
Contains three little
finger muscles
Deep motor branch of
the ulnar nerve
Compartments of the hand-Four interosseous spaces
Palmar and dorsal interosseous
muscles
Deep motor division of the ulnar
nerve
Clinical Correlate: Dupuytren’s Contracture
•Flexion contracture of the hand •Thickening and contraction of the palmar aponeurosis •Nodule formation •Unable to extend fingers
Clinical Correlate: Dupuytren’s Contracture-Treatment
•Needle aponeurotomy is a minimally invasive technique where the cords are weakened through the insertion and manipulation of a small needle. Once weakened, the offending cords may be snapped by simply pulling the finger(s) straight
Clinical Correlate: Dupuytren’s Contracture-Surgery
cutting out thickened
and contracted bands in palmar
aponeurosis
Fibrous digital tendon sheaths
-dense connective tissue surrounding tendons of FDP, FDS & FPL muscles -Hold tendons to the phalanges and prevent bowing
Synovial sheaths
Within the fibrous sheath
the tendon has a synovial
sheath directly surrounding
it
Radial Bursa
Synovial sheath surrounding the
tendon of FPL continuing through to
carpal tunnel
lnar bursa – common
flexor sheath
Synovial sheath surrounding the tendons of FDP & FDS of 5th digit continuing through the midpalmar space and into the carpal tunnel
Clinical Correlate: Trigger finger (Stenosing Tenosynovitis)
•Fibrosis and tightening of the fibrous digital sheath of the flexor tendons at the level of the metacarpophalangeal (MCP) joint •Inflammation and nodule formation of the flexor tendons. •Triggering of the affected finger is due to tendons requiring excessive force to fully extend or flex
Extensor hood
Tendons of extensor digitorum and extensor pollicis longus expand over the proximal phalanx, makes a “hood” which then divides into a central band and 2 lateral bands
Extensor hood -Serves as an attachment for
• Lumbricals • Dorsal interossei • Palmar interossei • Due to attachment, these
muscles also extend at the
interphalangeal joint
Dorsal interosseous
Abduction of digits
• Extension of digits
• Deep branch of the ulnar
nerve
Palmar interosseous
• Adduction
• Extension of digits
• Deep branch of the ulnar
nerve
Adductor policis
• Adducts the thumb
• Deep branch of the
ulnar nerve
Blood supply of the hand
-Superficial palmar arch
Mainly from ulnar artery
-Deep palmar arch
Mainly from radial artery
Lumbricals
• 1 st-2nd palmar digital branches of median nerve • 3rd-4th Deep branch of ulnar nerve • Flex metacarpophalangeal (MCP) joints and extend interphalangeal joints of digits 2-5
Thenar Group
Recurrent branch of the median nerve 1. Flexor policis brevis 2. Abductor policis brevis 3. Opponens pollicis
Hypothenar Group
Deep branch of the ulnar nerve 1. Flexor digiti minimi 2. Abductor digiti minimi 3. Opponens digiti minimi
Clinical Correlate: Allen Test
- Erythema – normal test
- Pallor – beware!
Venous drainage of
hand-Superficial veins:
On the dorsum of the hand, the dorsal venous network coalesces on the medial side of the wrist to form the basilic vein and on the lateral side of the wrist to form the cephalic vein
Venous drainage of
hand- Deep veins:
• Superficial and deep venous palmar arches accompany arterial palmar arches in the hand • Drain into the paired radial and ulnar veins
Lymphatic drainage of
Upper Limb
• Follows the same path of the venous drainage of the upper limb • All lymphatics drain to the axillary nodes -• All lymph then pass from apical to subclavian trunk to lymphatic/thoracic duc
Lymphatic drainage of
Upper Limb-Superficial drainage: veins within the
skin and superficial fascia
-Medial hand, forearm and arm • Lymphatic fluid will go to lateral (humeral) axillary nodes, then to central axillary nodes, then finally to apical axillary nodes -Lateral hand, forearm and arm • Lymphatic fluid will go directly to the apical axillary nodes
Lymphatic drainage of
Upper Limb-Deep drainage: veins within the
compartments
• Lymphatic fluid from the compartments of
hand, forearm and arm will go to lateral
(humeral) nodes, then to central then
finally to apical
