Hand Flashcards
- continuation from antebrachial fascia
- blends with palmar carpal ligament and palmaris longus tendon
palmar aponeurosis
- composed of annular and cruciform parts
- holds flexor tendons to phalanx during flexion
fibrous digital sheath
lies deep to palmar aponeurosis and palmaris longus, part of the palmar fascia
flexor retinaculum (transverse carpal ligament)
dense connective tissue band that bridges between trapezium and pisiform plus hook of hamate, forms roof of carpal tunnel
flexor retinaculum (transverse carpal ligament)
- progressive shortening, thickening, and fibrosis of palmar fascia and aponeurosis
- affects 4th and 5th fingers, pulled into partial flexion
- commonly bilateral, male, over 50
- treat: collagenase injections, surgical excision of fibrotic parts
Dupuytren’s Contracture of palmar fascia
superficial (no compartment), wrinkles hypothenar skin, aids in palmar gripping
palmaris brevis
function of the three thenar muscles?
opposition of the thumb
- abducts carpometacarpal join of thumb, assists with early opposition
- thenar muscle
abductor pollicis brevis
- medial to abductor pollicis brevis
- flexes thumb
- innervated by median nerve
- thenar muscle
flexor pollicis brevis
- lies deep to abductor pollicis brevis
- opposes thumb (requires flexion and medial rotation of 1st metacarpal bone)
- thenar muscle
opponens pollicis
- most ulnar, located under palmaris brevis
- abducts 5th digit
- hypothenar muscle
abductor digiti minimi
- lateral to abductor digiti minimi
- flexes 5th digit
- hypothenar muscle
flexor digiti minimi
- deepest hypothenar muscle
- opposition of 5th metacarpal (requires flexion and lateral rotation)
opponens digiti minimi
- flex metacarpophalangeal joint, extend interphalangeal joints
- digits 1&2 by median nerve, 3&4 by ulnar nerve
- L or Z movement
- originate from tendon of flexor digitorum profundus
lumbricals
adducts thumb, innervated by ulnar nerve
adductor pollicis
abducts digits, ulnar nerve
dorsal interossei
adducts digits, ulnar nerve
palmar interossei
muscle bellies in the forearm, only tendons enter hand, important synovial sheaths
extrinsic muscles of the hand
split and attach to base of middle phalanx
FDS tendons
don’t split, attach to bade of distal phalanx
FDP tendons
- cause: injury such as puncture of palm by rusty nail
- swelling digits, painful movement
- infxn can spread to palm, carpal tunnel, forearm
- if digital synovial sheath ruptures can spread into midpalmar space
tenosynovitis (infection of synovial sheath)
- excessive friction of tendons of abductor pollicis longus (APL) and extensor pollicis brevis (EPB)
- fibrous thickening of synovial sheath
- pain in wrist, radiates to forearm and thumb
- test: hold thumb inside 4 fingers and adduct (ulnar deviate) wrist join
De Quervain’s Tenovaginitis Stenosans
- repetitive forceful use of fingers causes thickening of fibrous digital sheath
- FDS and FDP tendons may enlarge, can’t extend finger
- passive extension produces snapping sound
Digital Tenovaginitis Stenosans (Trigger finger)
enters hand in Guyon’s canal (anterior to flexor retinaculum), b/w pisiform and hook of hamate
ulnar artery
-main termination of ulnar artery, branches out common palmar digital arteries
superficial palmar arch
-main termination of radial artery, through anatomical snuffbox
-branches out palmar metacarpal arteries
-
deep palmar arch
- passageway deep to flexor retinaculum (transverse carpal ligament)
- b/w tubercles of scaphoid & trapezium and pisiform and hook of hamate
- 9 tendons (4 FDS, 4 FDP, 1 FPL)
- median nerve passes through
Carpal Tunnel
- supplies 3 thenar muscles, 1st and 2nd lumbricals
- innervates skin on lateral palm, side of digits 1,2,3, lateral half of digit 4, distal half of dorsum of these fingers
median nerve
enters palm region superficial to carpal tunnel, not affected by carpal tunnel syndrome
palmar branch of median nerve
- lesions of tendons or synovial sheaths (inflammation, infection, fluid retention, excessive exercise)
- sensation changes in median nerve supply area, thenar muscle weakness
- Dx: median nerve related symptoms, reduce by pressing on wrist for 30 seconds
carpal tunnel syndrome
superficial to flexor retinaculum and palmar aponeurosis, supplies skin on medial side of palm
palmar cutaneous branch of ulnar nerve
supplies medial one and a half digits on anterior surface
superficial branch of ulnar nerve
supplies hypothenar muscles, medial two lumbricals, adductor pollicis, all the interossei
deep branch of ulnar nerve
supplies medial half of dorsum of hand, 5th digit, half of 4th digit
dorsal branch of ulnar nerve
- cause: gunshots, stab wounds, fracture of distal humerus, olecranon, head of radius
- clawhand, deviates to radial side when flex the wrist
ulnar nerve injury
innervates skin of lateral 2/3 of dorsum of hand, dorsum of thumb, lateral one and a half digits on proximal part
radial nerve
