Wrist & Hand Region Flashcards
Between metacarpals & proximal phalanx
Flexion: flexor digitorum superficialis & profundus; lumbricals muscles
Adduction: palmar interosseous muscles (PAD)
Abduction: dorsal interosseous muscle (DAB)
Metacarpopharyngeal (MP) joint
Between proximal & middle phalanges
Flexion: flexor digitorum superficialis
Proximal interphalangeal (PIP) joint
Between middle & distal phalanges
Flexion: flexor digitorum profundus
Distal interphalangeal (DIP) joint
Carpal tunnel syndrome
Tendosynovitis caused by repetitive hand movements –> compresses the median nerve
Flexor retinaculum
- composed of volar carpal ligament & transverse carpal ligament
- forms the carpal tunnel
Structures that pass through the carpal tunnel:
- Flexor digitorum superficialis tendons
- Flexor digitorum profundus tendons
- Flexor pollicis longus tendon
- Median nerve
- no arteries pass through this tunnel
SSX:
- sensory loss: palmar & dorsal aspects of index, middle, & half of ring finger & on palmar aspect of the thumb
- flattening of thenar eminence (ape hand)
- tingling sensation produced by tapping the Palmaris longus tendon (Tinel test)
- symptoms elicited by forced flexion of wrist & to alleviate them by wrist extension (Phalen test)
Slashing of the wrist (“suicide cuts”)
Deep laceration on radial side of the wrist may injure the ff:
- radial artery
- median nerve
- flexor carpi radialis tendon
- palmaris longus tendon
Deep laceration on ulnar side of the wrist may injure the ff:
- ulnar artery
- ulnar nerve
- flexor carpi ulnaris tendon
Fracture of the scaphoid
Most commonly fractured carpal bone
Articulates with radius at the radiocarpal joint
Associated with osteonecrosis of scaphoid bone (proximal fragment)
SSX: tenderness in anatomic snuffbox (formed by extensor pollicis longus & brevis & abductor pollicis longus tendons) because the scaphoid lies in the floor of the snuffbox
X-ray may be normal for several weeks until bone resorption occurs
COLLE’S fracture
Posterior displacement of distal portion of radius (dinner fork deformity)
Fall on outstretched hand with wrist extended
Often with fracture of ulnar styloid process
Boxer fracture
Fracture at the head of 5th metacarpal (little finger)
Closed fist is used to hit a hard object
SSX: pain on ulnar side of the hand, depression of the head of the 5th metacarpal, +pain on flexion
Gamekeeper thumb
Disruption of the ulnar collateral ligament of the Mp joint of the thumb
Skier’s thumb gets entangled with the ski pole during a fall
Associated with avulsion fracture at the base of proximal phalanx of the thumb
Volkmann ischemic contracture
Causes contraction of the forearm muscles
Associated with the ff:
- supracondylar fracture of humerus in which the brachial artery goes into spasm, reducing blood flow
Cast that is too high
Compartment syndrome (muscles are subjected to ⬆️ pressure due to edema or hemorrhage)
DUPUYTREN’S contracture
Thickening & contracture of palmar aponeurosis–> progressive flexion of fingers
More pronounced in the ring & little fingers
Highly correlated with coronary artery disease (due to vasospasm caused by sympathetic inner still of e vasculature within T1 component of ulnar nerve)
Articulation of concave distal end of radius with scaphoid & lunate carpal bones
Flexion/extension
Abduction/adduction
Wrist (radiocarpal) joint
