A: Back of hand Flashcards
Monteggia’s fracture
Result of force from behind ulna
Proximal ulna is fractured, head of radius dislocated anteriorly at elbow
Galeazzi’s fracture
Fracture of distal radius
Head of ulna dislocates at distal radio-ulnar joint
Colles fracture
Fracture + posterior displacement of distal radius
From falling onto outstretched hand
‘Dinner fork deformity’
What ligaments are present in wrist joint
Palmar radiocarpal ligament, dorsal radiocarpal ligament, ulnar collateral ligament, radial collateral ligament.
Type of joints in carpometacarpal
Joints between carpal + metacarpal bones are plane synovial, except thumb which is saddle synovial.
Extensor digitorum (origin, insertion, nerve supply, action)
- Common extensor origin
- Via extensor hoods into base of middle + distal phalanges.
- Radial
- Extends finger at PIP and DIP, MP joint + wrist
Extensor digiti minimi
- Common extensor origin
- Extensor hood of little finger
- Radial
- Extends little finger
Extendor indicis
- Posterior surface of ulna
- Extensor hood of index finger
- Radial
- Extends index finger
Abductor pollicis longus
- Posterior surface of ulna + radius
- Base of 1st metacarpal
- Radial
- Abducts thumb at CMC joint
Extensor pollicis brevis
- Middle 1/3 radius + interosseous membrane
- Base of proximal phalanx of thumb
- Radial
- Extends thumb at MP + CMC joint
Extensor pollicis longus
- Middle 1/3 ulna + interosseous membrane
- Base of distal phalanx of thumb
- Radial
- Extends all joints of thumb
Extensor carpi radialis longus
- lateral aspect of lower humerus
- base of 2nd metacarpal
- radial
- Extend + abduct wrist
Extensor carpi radialis brevis
- Common extensor origin
- Base of 2nd and 3rd metacarpal
- Radial
- Extends + abducts wrist
Extensor carpi ulnaris
- common extensor origin + upper ulna
- Base of 5th metacarpal
- Radial (posterior interosseous branch)
- Extends and adducts wrist
Brachioradialis
- Lateral side of lower humerus
- Lower part of radius just above styloid process
- Radial
- Flexes elbow
Supinator
- Superficial part: common extensor origin, Deep part: crest of ulna
- Upper part of radius
- Radial
- Supination
Deep branch of radial nerve:
supplies supinator, extensor carpi ulnaris + all extensors of fingers.
Emerges as posterios interosseous nerve to run between superficial + deep muscles of posterior compartment in arm.
Superficial branch of radial nerve
-Supplies skin of lateral. 2/3 dorsum of hand + dorsal aspects of lateral 3.5 ingers.
Injury to radial nerve in axilla
- Paralysis of extensor muscles in upper limb
- Cannot extend wrist and MP joints as muscles of posterior compartment paralysed
- IP joints of fingers can be extended
- Paralysis of triceps = cannot extend elbow.
- Numbness of dorsal aspect of arm, proximal parts of lateral 3.5 digits
Injury to radial nerve in spiral groove
- Paralysis of muscles in posterior compartment of forearm - supination impaired, cannot extend wrist at MP joint. Interossei and lumbricals supplied by media and ulnar nerves, so IP joints can be extended.
- Loss of sensation on dorsal aspect of hand + proximal parts of lateral 3.5 digits.
Posterior superficial muscles
ECRB ECRL ECU ED B
Posterior deep muscles
Supinator, EPB EPL EI APL
Superficial muscles in back of forearm
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Brachioradialis
- Extensor carpi radialis longus
Deep muscles in back of forearm
- Abductor pollicus longus
- Extensor pollicus brevis
- Extensor pollicus longus
- Extensor indicis
- supinator
A man has pain on the lateral side of his elbow following a
weekend of gardening. On examination, the area of the lateral epicondyle of humerus is tender. You suspect a localized tearing of the origin of a muscle. What muscles originate here?
Extensor digitorum, Extensor digiti minimi, Extensor carpi radialis brevis, Extensor carpi ulnaris, Supinator.
When is the radial nerve vulnerable to injury?
Fracture of midshaft of humerus (spiral groove)
Fracture and dislocation of proximal humerus.
Excessive pressure in axilla eg arm over chairback: ‘Saturday night
palsy’
What is the function of the articular disc at the wrist joint?
The articular disc binds radius and ulna together during movement. It separates the joint cavity of distal radio-ulnar joint from cavity of wrist (radio-carpal) joint. Different movements take place at each joint.
