Wrist Hand Anatomy Flashcards
Wrist Flexion (musc, inn.)
FCR: C6-7, upper and middle trunk, lateral cord, median n.
FCU: C8-T1, lower trunk, medial cord, ulnar n.
to lesser degree:
FDS
FDP
FPL
PL
Wrist extension (musc, inn.)
ECRL, ECRB: C6-7, upper and middle trunk, posterior cord, radial n.
ECU: C7-8, middle and lower trunk, posterior cord, radial n., PIN
lesser degree:
ED
EIP
EPL
EDM
Ulnar deviation (musc, inn.)
FCU: C8-T1, lower trunk, medial cord, ulnar n.
ECU: C7-8, middle and lower trunk, posterior cord, radial n., PIN
Radial deviation (musc, inn.)
FCR: C6-7, upper and middle trunk, lateral cord, median n.
ECRL, ECRB: C6-7, upper and middle trunk, posterior cord, radial n.
Carpal Tunnel (volar side of wrist)
4 FDS tendons
4 FDP tendons
FPL tendon
median n.
all under flexor retinaculum
bordered by scaphoid (radially) and pisiform (ulnarly)
Dorsal side of wrist
6 compartments
1st: APL, EPB (DeQuevain Tenosynovitis)
2nd: ECRL, ECRB
3rd: EPL (Drummer’s wrist)
4th: ED, EIP (4 fingers, 4th compartment)
5th: EDM (5th finger, 5th compartment; Vaughn Jackson syndrome)
6th: ECU (common source snapping in wrist)
Colles v Smith fracture
types of distal radius fractures
Colles: distal radius fragment is dorsally displaced (CD)
Smith: distal radius fragment is volarly displaced (Sweater Vest)
scaphoid fracture
pain in anatomic snuffbox
most common at scaphoid waist
immobilize w thumb spica case, repeat XR in 2 wks if initial XR negative but still suspect scaphoid fx
proximal ⅓ of scaphoid has highest risk of AVN → consider surgery (also if fx is displaced)
Kienbock disease
idiopathic AVN of lunate
Px: pain over dorsal wrist, ulnar to snuffbox
Dx: PE (pain on palpation), XR
hamate fracture
Px: pain worse w swinging bat or golf club
Tx: short arm cast (non displaced)
½ LOAF muscles
median innervated hand muscles:
½ lumbricals (thumb sided)
opponens pollicus
abductor pollicus brevis
flexor pollicus brevis
finger abduction v adduction (musc, inn.)
ABd: dorsal interossei (DAB); ulnar n.
ADd: palmar interossei (PAD); ulnar n.
3 PADs, 4 DABs
B before D, D before P (aBduct, aDduct; DAB, PAD)
Finger flexion (musc, inn)
PIP flexion: FDS; C7-8, middle and lower trunk, medial and lateral cord, median n.
DIP flexion:
FDP digits 2 and 3; C7-T1, medial cord, median n. and AIN
FDP digits 4 and 5; C7-T1, medial cord, ulnar n.
thumb flexion (musc, inn)
FPL: C7-T1, middle and lower trunk, medial and lateral cord, median n. and AIN
FPB: C8-T1, lower trunk, medial cord, median AND ulnar n
finger extension (musc, inn)
digits 2-5:
EDC: C7-8, middle and lower trunk, posterior cord, radial n. and PIN
attaches to extensor expansion
digit 2:
EIP: C7-8, middle and lower trunk, posterior cord, radial n. and PIN
thumb extension: EPL
digit 5: ADM
Boxer’s fracture
metacarpal neck/shaft fracture
5th metacarpal fracture, usually
after punching something very hard
Skier’s thumb
1st UCL injury of the MCP d/t excessive radial deviation → UCL strain
test for RCL/UCL injuries by applying lateral force
Stener’s lesion
trapping of thumb adductor aponeurosis in the MCP joint d/t severe UCL tear → ortho referral +/- surgery
MCP/PIP/DIP collateral ligament injury
d/t excessive varus of valgus deviation
Tx: extension splint or buddy tape
Dupuytren contracture
palmar fascia thickens into fibrous cords → painless swelling and flexion contracture (usually 4th digit)
RFs: older male, seizures/DM/acloholism
Trigger finger
stenosing tenosynovitis at A1 (MCP) pully of a finger flexor → nodule forms → prevents flexor tendon from gliding through smoothly
finger tends to snap/catch when flexing/extending
Jersey finger
REQUIRES SURGERY
FDS or FDP tendon avulsion d/t sudden hyperextension (e.g., getting caught in a player’s jersey) → pain/swelling in finger/palm → inability to flex PIP or DIP
Mallet finger
sudden DIP flexion → extensor tendon rupture +/- avulsion fracture (bony fragment) → painful/swollen distal finger → inability to extend DIP
Tx: DIP extension splint to allow tendon to heal for several weeks
surgery if big avulsed bone fragment
