Extensor Tendon Injuries Flashcards
How many extensor compartments of the wrist are there?
6
What is in the first extensor compartment?
Abductor Pollicis Longus
Extensor Pollis Brevis
What is in the 2nd extensor compartment?
Extensor Carpi Radialis Longus
Extensor Carpi Radialis Brevis
What is in the 3rd extensor compartment?
Extensor pollicis longus
What is in the 4th extensor compartment?
Extensor digitorum communis (EDC)
Extensor indicis proprius
What is in the 5th extensor compartment?
Extensor digiti minimi
What is in the 6th extensor compartment?
Extensor carpi ulnaris
What extensors outline the anatomical “snuff box”?
Extensor pollicis brevis
Abductor pollicis longus
Extensor pollicis longus
What constitutes DeQuervain’s Syndrome?
Inflammation of the sheath or tonnel that surroundings the two tendons of the thumb that control movement
Extensor pollicis brevis
Abductor pollicis longus
What is intersection syndrome?
Pain of the forearm where the two muscles that connect to the thumb cross over the underlying wrist tendons E
What is extensor tenosynovitis?
Irritation of the tendons located in the fourth extensor compartment
What is snapping extensor carpi ulnaris syndrome?
And why does this occur?
Painful “snap” over the ulnodorsal aspect of the wrist with rupture of the ECU subsheath in the 6th dorsal compartment
It is the only extensor tendon that has a true sheath so if it Is torn it leads to the snapping/popping
What is Vaughan Jackson Syndrome?
Inability to extend the metacarpal phalangeal joints of the ring and small fingers due to extensor tendon rupture beginning on the ulnar side of the hand and wrist
Where does extensor carpi radialis longus attach?
Where does extensor carpi radialis brevis attach?
ECRL on 2nd metacarpal
ECRB on 3rd metacarpal
What are the functions of the interossei?
DAB - dorsal abduct
PAD - palmar adduct
What nerve innervates interossei?
Ulnar nerve
Where does the extensor tendon trifurcate?
Extensor tendon trifurcates into a central slip and two lateral slips
How do the extensor tendons get nutritional and vascular supply?
Nutrition is similar to flexor tendons, synovial fluid diffusion, endogenous circulation, exogenous circulation
Vascular - multiple sources, but there is no vincular vessels
How many zones of injury are there for extensor tendons?
9
What are the zones of extensor tendon injury 1-9?
Zone 1: over the distal IP joint Zone 2: over the middle phalanx Zone 3: over the proximal IP joint Zone 4: over proximal phalanx Zone 5: over MP joint Zone 6: over metacarpals Zone 7: over carpus Zone 8: distal forearm/retinaculum Zone 9: proximal forearm
How many thumb zones are there for extensor tendon injury?
5
What are the zones of thumb extensor injuries 1-5?
Zone T1: over IP joint Zone T2: over proximal phalanx Zone T3: over MP joint Zone T4: over metacarpal Zone T5: over carpus
What is a good way to remember the extensor tendon zones?
Odd zones are over joints
Even zones are between joints
What zone is mallet finger considered?
Zone 1
What are all extrinsic extensors innervated by?
Radial nerve
What are lumbricals of index finger and middle finger innervated by?
Median nerve
What are the lumbricals of the ring finger and small finger innervated by?
Ulnar nerve
Which zone are fight bite injuries likely to occur?
Zone 5
