Chapter 12 - Wrist Flashcards
Radiocarpal joint
consists of the distal end of the radius and the radioulnar disk proximally and the scaphoid, lunate, and triquetrum distally
Condyloid joint
RC joint classification that allows for biaxial flexion and extension, radial deviation, and ulnar deviation
Midcarpal joint
located between the two rows of carpal bones and allow gliding motions, which collectively contribute to motion of the wrist.
Intercarpal joints
located between the carpal bones in each individual row and allow gliding motions, which collectively contribute to motion of the wrist.
Carpometacarpal (CMC) joints
appear between the distal row of carpal bones and the proximal end of the metacarpal bones
Which plane and axis do radial and ulnar deviation occur?
plane: frontal
axis: sagittal
Radial collateral ligament
attaches to the styloid process of the radius and to the scaphoid and trapezium bones
Ulnar collateral ligament
attaches to the styloid process of the ulna and to the pisiform and triquetrum
Palmar radiocarpal ligament
a broadband that attaches from the anterior surface of the distal radius and ulna to the anterior surface of the proximal carpal bones and to the capitate bone in the distal row
Dorsal radiocarpal ligament
attaches from the posterior surface of the distal radius to the same surface of the scaphoid, lunate, and triquetrum
Articular disk
- located on the distal end of the ulna and articulates with the triquetrum and lunate bones
- It acts as a shock absorber and as a filler between the distal ulna and its adjacent carpal bones—the triquetrum and lunate
- The disk fills the gap created because the ulna and its styloid process do not extend as far distally as the radius and its styloid process.
Palmar aponeurosis
- relatively thick, triangular fascia located superficially in the palm of the hand
- covers the tendons of the extrinsic muscles and provides some protection to the structures in the palm
- distal attachment of the palmaris longus, which blends into this fascia, as does the flexor retinaculum
Common Flexor tendon
a single tendon that originates on the medial epicondyle of the humerus. It gives rise to many muscles that are prime movers for flexion at either the wrist or the hand
- pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, and flexor carpi ulnaris.
Common Extensor tendon
Originates on the lateral epicondyle. This single tendon gives rise to many muscles that are prime movers for either wrist or finger extension
- extensor carpi radialis longus and brevis, extensor carpi ulnaris, extensor digitorum, and extensor digiti minimi.
Flexor carpi ulnaris origin
medial epicondyle of humerus
Flexor carpi ulnaris insertion
pisiform and base of 5th MC
Flexor carpi ulnaris action
wrist flexion and ulnar deviation
Flexor carpi ulnaris nerve
ulnar nerve
Flexor carpi radialis origin
medial epicondyle of the humerus
Flexor carpi radialis insertion
base of 2nd and 3rd MC
Flexor carpi radialis action
wrist flexion and radial deviation
Flexor carpi radialis nerve
median nerve
Palmaris longus origin
medial epicondyle of humerus
Palmaris longus insertion
palmar aponeurosis
Palmaris longus action
assistive in wrist flexion
Palmaris longus nerve
median nerve
Extensor carpi radialis longus origin
supracondylar ridge of humerus
Extensor carpi radialis longus insertion
base of 2nd MC
Extensor carpi radialis longus action
wrist extension and radial deviation
Extensor carpi radialis longus nerve
radial nerve
Extensor carpis radialis brevis origin
lateral epicondyle of humerus
Extensor carpis radialis brevis insertion
base of 3rd MC
Extensor carpis radialis brevis action
wrist extension
Extensor carpis radialis brevis nerve
radial nerve
Extensor carpi ulnaris origin
lateral epicondyle of humerus
Extensor carpi ulnaris insertion
base of 5th MC
Extensor carpi ulnaris action
wrist extension and ulnar deviation
Extensor carpi ulnaris nerve
radial nerve
Extensor retinaculum
contains all of the wrist, hand, and thumb tendons
Colles fracture
a break in the distal radius at the level of the metaphysis and is a common injury in the elderly
Smith’s fracture
distal fragment is displaced anteriorly (reverse Colles) and is caused by a fall on the back of the hand
Greenstick fracture
incomplete fracture, usually of the radius and more proximal than a Colles fracture. It is more common in children than adults
Scaphoid fracture
sometimes associated with damage to the blood vessel that supplies this bone and can lead to avascular necrosis
Avascular necrosis
death of bone tissue
Ganglion cyst
benign, fluid-filled cyst commonly seen as a bump on the dorsal surface of the wrist.
Wrist sprians
common when a person falls on the outstretched hand. The wrist is usually hyperextended when the hand hits the ground.
