wrist/hand

carpal bones make up the wrist joint

8

proximal row of carpal bones

scaphoid, lunate, triquetrum ,pisiform

distal row of carpal bones

trapezium, trapexoid, capitate, hamate

articulates with both rows connecting them

scaphoid

central with multiple articulations

lunate

smallest carpal bone, sits anteriorly

pisiform

articulates with 1st MC of thumb

trapezium

small anterior bony prominence known as “hook” of hamate

hamate

Scaphoid and lunate articulate with distal radius blankly to form

laterally, radiocarpal joint

Carpal bones of wrist form crescent shape and are blank anteriorly forming

concave, carpal tunnel

Hand bones are made up of

metacarpals and phalanges

Joints located between proximal phalanges and

corresponding metacarpals

metacarpo-phalangeal joint

blank MCP has widest ROM allowing it to oppose

each of the fingers

1st

Proximal ends of MC’s articulate with carpal

bones at

carpo-metacarpal joints

Each finger has 3 phalanges

-prox

-mid

-distal

3 phalanges form two joints

proximal and dital interphalangeal joint

phalanges of thumb

proximal and distal

thumb joint

one, interphalageal joint

Space between distal ulna and carpal bones

triangular fibrocartilage complex

triangular fibrocartilage complex serves to

stabilize and cushion wrist joint

listers tubercle is located on blank aspect

dorsal

important palpable landmark located on dorsal aspect of

radius between 2nd and 3rd compartment

Lister’s tubercle

tendons in compartment one

2

tendons in compartment two

2

tendons in compartment three

one

tendons in compartment four

two

tendons in compartment five

one

tendons in compartment six

one

Triangular depression between radial styloid process and base of 1st MC.

anatomical snuff box

anatomic snuff box contains

radial artery, superficial branch of radial nerves and sometimes cephalic vein

medial boundary of anatomical snuff box

extensor pollicis longus tendon

lateral boundary of anatomical snuff box

extensor pollicis brevis and abductor pollicis longus

floor extensor pollicis brevis and abductor pollicis longus

scaphoid and trapezium, extensor carpi radialis longus & brevis tendons

Flexor tendons of forearm muscles travel through

carpal tunnel

Flexor retinaculum – aka

transverse carpal ligament

Flexor retinaculum proximally stretches from

pisiform to scaphoid

Flexor retinaculum distally

hook of hamate to trapezium

Flexor retinaculum forms

carpal tunnel

proximal and more superficial to flexor retinaculum

Palmar carpal ligament

Space between flexor retinaculum and palmar carpal ligament is called

ulnar canal

Continuous with extend retinaculum of dorsal wrist

palmar carpal ligament

Contents of the carpal tunnel include

• Four flexor digitorum superficialis tendons

• Four flexor digitorum profundus tendons

• Median nerve

• Flexor pollicis longus

Guyon’s canal aka

ulnar canal

Space at the wrist between the pisiform and

the hamate through which the ulnar artery

and nerve travel into hand.

Guyon’s canal

palm muscular area lateral at base of thumb

thenar eminence

palm muscular area medially

hypothenar eminence

course anteriorly, distally separate to insert on side of each phalange

flexor digitorum superficialis

what courses deep to flexor digitorum superficial

Flexor digitorum profundus

A1 pulley located near head of

MC

A2 located on

prox phalanx

A4 centrally on

middle phalanx

A5 (sometimes) found on

base of dital phalanx

Pulley System

• Each annular pulley

attachment to the bone is

wider than the roof of the

tunnel

• This prevents pulley from

pinching neighboring

structures at extreme

flexion

how to scan wrist and hand

-pt sits with hand+wrist on table

-high frequency 15-10MHZ

patient positioning for volar

• Hands and wrist must be palm up, slight dorsiflexion can help, along with radial

and ulnar deviation

scanning volar carpal tunnel

• For evaluation of the median nerve, the transducer is placed in the

transverse plane at the level of the wrist crease, which is at the proximal

aspect of the carpal tunnel

Patient Positioning - Dorsal

Wrist and hand placed palm down with mild volar flexion

• Imaged in SAX plane using Listers tubercle as a landmark

Between radius and ulna

distal radioulnar joint

Wrist/hand patholgy

• Tenosynovitis

• De Queravains

• Intersection Syndrome

• Carpal Tunnel

• Ganglion cysts

• Trigger Finger

appears as nondisplaceable and poorly or noncompressible distention of a joint recess that is hypoechoic

Synovial hypertrophy

DeQuervains disease involves

1st dorsal extensor compartment containing abductor pollicis longus and extensor pollicis brevis tendons

Tendinitis resulting in pain over thumb side of wrist

De Quervain’s Disease

De Quervain’s Disease is due to

repetitive strain injury from twisting, pinching, or grasping of the

hand and thumb

acute apperance of de quervain’s disease

Hypoechoic tendons and synovium will be present on sonographic

evaluation

chronic apperance of de quervain’s disease

echogenic from fibrosis. Fibrosis decreases the mobility to move the

thumb away from the hand or straighten the thumb after grasping

sonography of dequervains disease

Tendon sheath will have fluid (simple or complex)

surrounding the hypoechoic tendon.

Most common type of

idiopathic synovitis in the wrist

Entrapment or compression neuropathy of the median nerve

Carpal Tunnel Syndrome

Causes pain and paresthesia (numbness/tingling) of 1st-3rd digits and radial side of 4th

carpal tunnel syndrome

• Pins and needles with

light tapping

Tinel’s sign

Tingling / burning /

numbness in Phalen's

position

phalens sign

Carpal Tunnel presentation

• Numbness of middle and

index finger

• Weakness, clumsiness of

hand with pain

-Tinel’s sign

-phalen’s sign

Sonographic appearance of Carpal Tunnel

Syndrome

• Proximal swelling of the nerve with distal flattening under the retinaculum

• Nerve will be enlarged and hypoechoic. Possibly hyperemic

• Enlargement causes bowing in the flexor retinaculum (on palm side)

• Using ellipse measurements, anything over 15mm2 at level of proximal tunnel

(level of pisiform bone) is diagnostic for increased median nerve area

• Eventually the muscles will hypertrophy

involves palmar fascia were as it contracts,

causes palpable lumps and fixed flexion of the hand and fingers. Inability to

extend hand and fingers

Dupuytren’s contracture

digits most commonly affected in dupuytren’s contracture

4th and 5th

Dupuytren’s Contracture Aka

palmar fibromatosis

sonography of Dupuytren’s Contracture

Thickening of fascia and shortening of flexor tendons

• Palpable lumps seen on US as hypoechoic masses (fibromas) of palmar

fascia

Trigger Finger Aka

stenosing tenosynovitis

locking of affected digit after flexion when

attempting to extend

trigger finger

Pathology of the pulley system forming fibro-osseous tunnels for passage of

finger flexors

trigger finger

trigger finger pop

woman 40-60

sonography of trigger finger

use high freq 15-18 MHz with small footprint

• Pulley will appear thickened and hyperemic

• Normal pully thickness is 0.5mm. Abnormal thickness averages 1.8mm

• Underlying tendon will appear to have tendinosis or tenosynovitis - thickening

tendon-making gliding of tendon under the pulley difficult

injury of tendon or ligament pulls on bony insertion and pulls off small piece of bone

Avulsion fractures

aka skiers

thumb or gamekeepers thumb

Avulsion of ulnar collateral ligament (UCL) of thumb

UCL becomes displaced

outside adductor aponeurosis

Stener lesion

Giant cell tumor – aka

nodular synovitis

Lesion arising from tendon sheath along volar surface of thumb, index and

middle fingers at level of DIP joint.

Giant cell tumor

presentation of giant cell

woman, painless, slow, growing, firm nodule

Sonography giant cell tumor

solid, hypoechoic with

well defined margins, internal

vascularity

• Nodule does NOT move with tendon

motion as it arises from the sheath

arise from

neuromyoarterial apparatus in

dermis of the nail bed

glomus tumor

sonography of glomus tumor

small (few mm’s), well

defined, solid, hypoechoic with

internal echogenicity, hypervascular

occurs when there is physical compression

(intrinsic or extrinsic) on the nerve

compression neuropathy

compression neuropathy reasons

instrinsic (nerve tumor), extrinsic (external structures)