Exam 2C- Anatomy - Hand and wrist

DeQuervain Tenosynovitis

- Washer-woman's sprain

- inflammation of sheath

- compartment 1 = abductor pollicis longus and extensor pollicis brevis

- now called "texters thumb"

ganglion cysts

- "bible bumps"

- cyst derived from tendon sheath of a tendon: common firm swelling on dorsum of hand/wrist

- can occur anywhere, but most common at scapho-lunate joint

Palmar carpal ligament

more proximal and superficial than the transverse carpal ligament; attaches to the styloid processes of the radius and ulna, and crosses over the flexor muscles

guyon's canal/ulnar canal

- between hamate and pisiform

- superficial to flexor retinaculum

- roof is the palmar carpal ligament, floor is flexor retinaculum

- ulnar a. and n.

carpal tunnel syndrome

- neurogenic (compression of median n.)

- symptoms: burning, tingling, itching, numbness in palm & fingers

distal radioulnar joint

pivot joint: head of ulna to ulnar notch of radius

- fibrocartilaginous radioulnar disk separates ulna from proximal carpals and holds ulna to distal radius- triquetral & lunate

radioulnar disk

- what unites radius and ulna during pronation/supination

- disk with distal radioulnar articulation's shape forms synovial cavity separate from radiocarpal joint's cavity

radiocarpal joint

wrist joint

- distal radius, fibrocartilaginous radioulnar disk, proximal row of carpals (radius to scaphoid & lunate)

- reinforced by radial collateral lig. of wrist and ulnar collateral lig. of wrist

radial collateral ligament

syloid process of radius to radial side of scaphoid

ulnar collateral ligament

syloid process of ulna to medial triquetrum and pisiform/transverse carpal ligament

thenar eminence

thumb

hypothenar eminence

little finger

cutaneous nerves

- palmar branch of median n.

- palmar branch of ulnar n.

- digital branches of median n.

- digital branches of ulnar n.

- superficial branch of radial n.

palmar branch of median n.

- begins before median n. enters carpal tunnel

- to mid palm

palmar branch of ulnar n.

- begins in wrist

- to medial palm

the hand

- entirely wrapped in fascia

- palmar and dorsal fascia continuous on sides

- thin, except at mid-palm

palmar aponeurosis

- thick fascia between thenar and hypothenar eminences. Reinforced by aponeuroses of palmaris longus muscles and divides into 4 slips that enter the fingers

- septum dives deep to attach to 3rd metacarpal (midpalmar septum)

midpalmar septum

divides the tendons of the flexor digitorum muscles, the thenar muscles, and the deeper lying interossei into 2 compartments:

1. the thenar space (deep to the thenar muscles

2. the midpalmar space (deep to the long tendons

midpalmar septum- clinical note

infections are restricted to the space in which it occurred (midpalmar or thenar), and numerous surgical approaches were described to open the space and drain the infected area

dupuytren''s contracture

- longitudinal slips of palmar aponeurosis develop cysts

- slips contract and produce passive flexion of affected fingers

palmaris brevis PA

palmar aponeurosis

palmaris brevis DA

skin over hypothenar eminence

palmaris brevis a & i

- action: increase palm concavity on hypothenar side

- innervation: ulnar n.

abductor pollicis brevis PA

trapezium and flexor retinaculum

abductor pollicis brevis DA

base of proximal phalanx

abductor pollicis brevis a & i

- action: abduct thumb, assist flexion at MP joint

- innervation: recurrent branch of median n.

flexor pollicis brevis PA

trapezium and flexor retinaculum

flexor pollicis brevis DA

base of proximal phalanx

flexor pollicis brevis a & i

- action: flex MP joint

- innervation: recurrent branch of median n.

opponens pollicis PA

trapezium and flexor retinaculum

opponens pollicis DA

shaft of 1st metacarpal

opponens pollicis a & i

- action: medially pulls and rotates 1st metacarpal into apposition position with another digit

- innervation: recurrent branch of median n.

adductor pollicis PA

- oblique: bases of 2nd and 3rd metacarpals

- transverse: shaft of 3rd metacarpal

adductor pollicis DA

base of proximal phalanx of thumb

adductor pollicis a & i

- action: adduct pollux

- innervation: deep branch of ulnar n.

abductor digiti minimi PA

pisiform and flexor retinaculum

abductor digiti minimi DA

base of proximal phalanx of digiti minimi

abductor digiti minimi a & i

- action: abduct pinky finger

- innervation: deep branch of ulnar n.

flexor digiti minimi brevis PA

hamate and flexor retinaculum

flexor digiti minimi brevis DA

base of proximal phalanx

flexor digiti minimi brevis a & i

- action: Flex MP joint

- innervation: deep branch of ulnar n.

opponens digiti minimi PA

Hook of hamate and flexor retinaculum

opponens digiti minimi DA

shaft of 5th metacarpal

opponens digiti minimi a & i

- action: pull 5th metacarpal toward midline and rotate into apposition position with thumb

- innervation: deep branch of ulnar n.

lumbricals PA

sides of tendons of flexor digitorum profundus

- 3 and 4 between tendons (unipennate 1 & 2) vs. bipennate (3 &4)

lumbricals DA

radial side of dorsal expansion of next highest numbered digit

- ex. 1st lumbrical goes to 2nd digit

lumbricals a & i

- action: flex MP and extend IP joints of fingers

- innervation: 1 & 2 = digital branches of median n. 3 & 4 = deep branch of ulnar n.

interossei in general

- palmar = 3

- dorsal = 4

- all are innervated by deep branch of ulnar n.

- All are able to extend PIP & DIP joints while stimultaneously flexing MP joints

palmar interossei PA

all attach to metacarpals

- #1 to medial side of 2nd, #2 to lateral 4th, #3 to lateral 5th

palmar interossei DA

dorsal expansion of same finger side as PA

palmar interossei a & i

- action: all adduct fingers and extend PIP and DIP joints while simultaneously flexing MP (PAD)

- innervation: deep branch of ulnar n.

dorsal interossei PA

surface of adjacent metacarpals

dorsal interossei DA

dorsal expansion

- 1st = index, 2nd & 3rd = either side of the middle finger, 4th = ring

dorsal interossei a & i

- action: abduct finger OR extend PIP and DIP joints while simultaneously flexing MP (DAB)

- innervation: deep branch of ulnar n.

radial n. in hand

- superficial branch of radial n. = prior, followed radial a.

- lateral branch = dorsal digital nerves (1)

- medial branch = dorsal digital nerves (2,3, radial side of 4)

median n. in hand

passes through carpal tunnel

- but the palmar cutaneous branch does not go through cubital tunnel

- after "tunnel", nerve becomes enlarged and flattened. gives off recurrent branch to thenar group.

- also called million dollar nerve: american football players have insurance on it because cleats stepping on the palm of the hand

common palmar digital nerves

- proper palmar digital branches: to pollux, index, middle fingers and radial half of ring finger (palmar and distal dorsal surfaces)

ulnar n. in hand

passes through guyon's canal and splits

1. superficial branch: terminal branch, cutaneous to ulnar portion of dorsal and palmar hand.

- common palmar digital nerve: proper palmar digital nerves to 5th finger and ulnar side of ring finger

2. deep branch: other terminal branch. to most intrinsic muscles of the hand

- traves with deep palmar branch of radial a. and ends at adductor pollicis

ulnar a.

- superficial branch: is the major supplier to- superficial palmar arch, gives off digital branches. Minor radial a. contributions

- deep branch: given off near pisiform and adds to deep palmar arch

radial a.

- dorsal carpal branch adds to dorsal carpal arch: gives off branches toward digits. princeps pollicis a., radialis indicis a.

- superficial palmar branch: to superior palmar arch- common palmar digital arteries, proper palmar digital arteries. terminates in deep palmar arch

intrinsic plus

- MP joints flexed and IP joints extended (nerves intact)

- safe position for hand splinting: collateral ligaments of MP and IP joints are taut (lengthened). Ideal for immobilization of most hand injuries = prevent contractures

intrinsic minus hand

IP joints flexed and MP joints extended

- injury to ulnar n. at wrist: if injury occurs at elbow- cubital tunnel syndrome, "claw" is less pronounced as deep flexors of 4th and 5th fingers are also paralyzed.

due to flexor digitorum profundas

intermetacarpal joints

deep transverse metacarpal ligaments

- transversely running ligamentous bands between distal metacarpal bones

- continuous with fibrous digital sheaths at each finger

- helps to stop hyperextension at PIP joints!!!!!!!!

swan neck deformity

PIP hyperextension with DIP flexion

- in worst casae, PIP hyperextension may lead to avulsion of ligaments

jammed finger

finger joint pain and swelling due to impact injury

mallet inger

a tear in dorsal expansion's connection to base of distal phalanx (unable to fully extend at DIP)