Extensor retinaculum

Question 1

What are the attachments of extensor retinaculum?

Answer 1

lateral: radius medial: flexor carpi ulnaris

Question 2

What are the contents of tunnel 1 of extensor retinaculum (lateral)?

Answer 2

adductor pollicis longus extensor pollicis brevis

Question 3

tunnel 2 of extensor retinaculum

Answer 3

extensor carpi radialis longus + brevis

Question 4

tunnel 3 of extensor retinaculum

Answer 4

extensor pollicis longus

Question 5

tunnel 4 of extensor retinaculum

Answer 5

extensor digitorum communis extensor indices

Question 6

tunnel 5 of extensor retinaculum

Answer 6

extensor digiti minimi

Question 7

tunnel 6 of extensor retinaculum (little finger - medial side)

Answer 7

extensor carpi ulnaris

Question 8

What structures are vulnerable to injury in the extensor retinaculum?

Answer 8

tendon of extensor pollicis longus (tunnel 3) is vulnerable to fraying and consequently rupture following fracture of radius. since adductor pollicis longus and extensor pollicis brevis (tunnel 1) share the same synovial sheath, repetitive thumb and wrist abduction can cause friction then inflammation = thickening and constriction of tendons causing pain radiating to base of thumb (stenosing tenovaginitis)