anatomy & positioning of the hand

carpal bones

- 8 carpal bones in each wrist - classified as short bones - 2 transverse rows 1. distal row - articulates with the metacarpals 2. proximal row - articulates with radius to form wrist joint - composed of cancellous bone with covering of compact bone and are held together by ligaments - the intercarpal joints are classified as gliding joints

image analysis of oblique finger

- IP and MP joints should be open, indicating that the phalanges are parallel to the IR - bony trabeculae present - the position best demonstrates an avulsion fracture of the distal phalanx

image analysis of oblique thumb

- IP and MP joints should be open, indicating that the phalanges are parallel to the IR - entire digit rotated 45 degrees, including metacarpal - thumb separated from other digits - bony trabeculae should be evident - view useful for avulsion fractures

hand joints

- MP joints are classified as Condyloid (flexion, extension, abduct & adduct) - metacarpals articulate with the distal row of carpal bones to form the CM joints - classified as gliding joints

carpal tunnel

- anterior or palmar surface of the carpal bones - concave - passing through the carpal tunnel is the median nerve and tendons of the flexor muscles of the digits

PA projection - finger

- center the MP joint of the affected digit to the center of section of IR - separate fingers to avoid overlapping soft tissue onto the affected digit - direct the CR perpendicular to MP joint of affected light - collimate to include from the distal phalanx to the CM joint of affected digit

image analysis for lateral finger

- concave anterior surface of the shaft of the phalanges - affected digit separated from others with no superimposition of soft tissue - IP and MP joints should be open, indicating that the phalanges are parallel to the IR - bony trabeculae should be evident

special view - Robert Method

- demonstrates arthritic changes, fractures, displacement of the 1st CM joint and Bennet's fracture of the base of the 1st metacarpal - rotate arm internally to place the posterior aspect of the thumb on the IR with the thumbnail down - pull other fingers back w/opposite hand - hyperextend hand so that the soft tissue of the ulnar aspect does not obscure the 1st CM joint - ensure the thumb is not obliqued - CR 15 degrees proximally (toward the wrist) to enter the 1st CM joint (helps to project soft tissue away from the 1st CM joint and helps to open the joint space)

radioulnar joint

- distal and proximal radioulnar joints are pivot joints, which allow us to supinate and pronate the hand - formed by the head of the ulna and the ulnar notch of radius

image analysis - lateral hand

- entire hand in lateral position, as evidenced by superimposed metacarpals and distal radius & ulna - individual phalanges in lateral position, with no overlapping bones - DIP and PIP joints open - thumb should appear in slight oblique position free of superimposition and joints open

image analysis oblique hand

- entire hand rotated 45 degrees, including metacarpals - minimal overlap of bases of 3rd-5th metacarpals - no overlap at midshafts of metacarpals - IP and MP joints open w/o overlap - digits separated - no overlap of soft tissue

image analysis of lateral thumb

- entire thumb in true lateral position as evident by concavity of both sides of phalanges - thumb separate from other digits - IP, MP and CM joints open w/o overlap of bone - trapezium superimposed on trapezoid - bony trabeculae present

45 degree oblique thumb

- flex elbow 90 degrees, with hand pronated - abduct thumb away from fingers - CR perpendicular to 1st MP joint

wrist joint proper

- formed by the base of the radius, scaphoid and lunate - triangular articulates with the base of the radius when the hand is in a PA position with ulnar flexion - classified as a condyloid joint (flexion, extension, abduction, adduction) - synovial joint enveloped in an articular capsule - strengthened by the radial collateral ligament and the ulnar collateral ligament

1st digit (thumb)

- has 2 phalanges 1. distal phalanx 2. proximal phalanx

2-5 digits

- have 3 phalanges apiece 1. distal phalanx 2. middle phalanx 3. proximal phalanx

AP thumb

- internally rotate forearm to place posterior surface of thumb against IR - instruct patient to hold other fingers back with opposite hand - CR perpendicular to 1st MP joint of the thumb

fingers/phalanges

- most distal bones of the hand - they are numbered and named from the lateral side beginning with the thumb (in the true anatomical side)

image analysis of AP thumb

- no rotation of digit as evident by concavity of both sides of phalanges - equal amount of soft tissue on either side of bone - IP, MP, CM joints open, w/o overlap of bone - bony trabeculae should be evident

image analysis - PA hand

- no rotation of hand - all bones are symmetrical - soft tissue - IP and MP joints are open w/o overlapping bone - bony trabeculae

anatomical snuff box

- on posterior lateral surface of the wrist (thumb side) is a triangular depression seen when thumb is abducted and extended - overlies the scaphoid and radial artery - tenderness in this area is indicative of a navicular/scaphoid fracture

carpal tunnel syndrome

- passing through the carpal tunnel is the median nerve and tendons of the flexor muscles of the digits - caused by repetitive movement or from overuse - patient experiences pain, burning and tingling sensation of the hands, radiating to the forearm

PA thumb

- performed ONLY when patient is unable to perform AP due to increased OID - place hand in lateral position, with fingers flexed away from thumb - abduct thumb away from hand, thumb parallel to IR - CR perpendicular to 1st MP joint

special view - arthritis study

- performed to evaluate the extent of arthritis in the joints of the hand - a comparison of both hands x-rayed on one IR simultaneously - place both hands on IR with hands in PA position - separate fingers slightly to prevent overlap of soft tissue - CR perpendicular to center of IR @ 3rd MP joint of each hand - upon request perform bilateral oblique & lateral hands

lateral hand - extension

- performed when requested by physician or radiologist - purpose is to localize foreign body or there is a fracture displacement of metacarpals (either anterior or posterior)

PA 45 degree oblique finger

- place affected digit against 45 degree angle sponge with thumb elevated - direct CR perpendicular to affected MP joint - include distal phalanx to the CM joint of affected finger 2nd digit positioning: - place thumb on IR, turn 2nd digit medially 45 degrees and rest other digits on angle sponge - direct CR perpendicular to 2nd MP joint

45 degree oblique hand

- place affected hand in 45 degree oblique position (semi-pronated) - make sure fingers are straight and parallel with plane of IR to avoid obscuring joint spaces - use of radiolucent step sponge will help keep fingers separated and parallel to the IR - CR perpendicular to 3rd MP joint

lateral thumb

- place hand in PA position, palm against IR - instruct patient to make a fist with fingers, thumb abducted away from hand - CR perpendicular to 1st MP joint

lateral projection - finger

- place hand in lateral position - thumb up - fully extend affected digit and place on IR - place affected digit against straight edge of sponge parallel with plane of IR - direct CR perpendicular to the PIP joint of affected digit - collimate to include distal phalanx to head of affected metacarpal - hand will be superimposed so affected metacarpal will not be demonstrated free of superimposition in lateral position

lateral hand - fingers fanned

- place hand in lateral position, with 5th digit in contact with IR, thumb up - spread fingers and thumb into a "fan" position - maintain lateral hand - metacarpals not obliqued - ensure fingers are parallel to IR - CR perpendicular to MP joints

PA hand

- seat patient at end of table with elbow flexed 90 degrees, affected hand and forearm resting on table - place hand with palm down in contact with IR - separate fingers to avoid overlapping soft tissue - CR perpendicular to 3rd MP joint - include soft tissue around entire hand

image analysis of PA finger

- should be no rotation of the digit - symmetrical appearance of both sides or concavities of the shafts of phalanges & metacarpals - equal amounts of soft tissue surround digit - IP and MP joints should be open w/o overlapping bone indicating that the hand was fully pronated - bony trabeculae should be evident - marked properly

special view - bone age

- special view of the left hand and wrist performed to determine if bone growth corresponds to chronological age in pediatric patients - many hereditary, hormonal & nutritional deficiencies are responsible for lack of growth in children - bone standards are determined by carpal bones and epiphyseal ossification centers - perform PA of left hand and wrist for children 1 year and older (at St Paul Childrens - 5 years and older) - annotate on image patient's exact age (year and month) and sex - images are compared with charts to determine appropriate appearance of carpal bones and epiphyseal plates at certain chronological ages

metacarpals

- the bones of the palm of the hand - numbered 1 - 5 - articulate with phalanges at their distal end (head) and the carpal bones at the proximal end (base)

Robert Method structures

1. 1st CM joint free of superimposition of the hand or other bony elements 2. 1st metacarpal with the base in convex profile 3. trapezium

routine projections of the thumb

1. AP or PA 2. 45 degree oblique 3. lateral

routine projections of the fingers

1. PA 2. 45 degree oblique 3. lateral

routine projections of the hand

1. PA 2. 45 degree semi-pronated oblique 3. lateral - with fingers fanned

anatomical structures of lateral finger

1. distal phalanx/DIP 2. middle phalanx 3. proximal phalanx/PIP 4. superimposed metacarpals

anatomical structures of PA finger

1. distal phalanx/DIP joint 2. middle phalanx 3. proximal joint/PIP joint 4. entire metacarpal/MP joint/CM joint

anatomical structures included in oblique

1. distal phalanx/DIP joint 2. middle phalanx 3. proximal phalanx/PIP joint 4. entire metacarpal/MP joint/ CM joint

anatomical structures AP thumb

1. distal phalanx/IP joint 2. proximal phalanx 3. 1st MP joint 4. 1st metacarpal/1st CM joint 5. trapezium

anatomical structures oblique thumb

1. distal phalanx/IP joint 2. proximal phalanx/1st MP joint 3. 1st metacarpal/1st CM joint 4. trapezium

anatomical structures of lateral thumb

1. distal phalanx/IP joint 2. proximal phalanx/MP joint 3. 1st metacarpal/CM joint 4. trapezium superimposed on trapezoid

anatomical structures - lateral hand

1. distal, middle & proximal phalanges 2. metacarpals and MP joints 3. carpal bones and CM joints 4. distal radius & ulna superimposed

anatomical structures oblique hand

1. distal, middle & proximal phalanges 2. metacarpals and MP joints 3. carpal bones and CM joints 4. distal radius and ulna

anatomical structures - PA hand

1. distal, middle and proximal phalanges 2. metacarpals and MP joints 3. sesamoid bone 4. carpal bones and CM joints 5. distal radius/ulna

carpal bones - proximal row (lateral to medial in true anatomical position)

1. scaphoid/navicular - fractures easily/difficult to heal due to poor blood supply, part of the wrist joint proper, special views are performed to demonstrate 2. lunate/semilunar - part of wrist joint proper 3.triangular/triquetrum/triquetral/cuneiform 4. pisiform - smallest carpal bone, rests on top of triangular

carpal bones - distal row (lateral to medial in true anatomical condition)

1. trapezium/greater multangular - forms the saddle joint with the 1st metacarpal 2. trapezoid/lesser multangular 3. capitate/Os Magnum - the largest carpal bone 4. hamate/unciform - has a distinguishable hook-like process called the hamular process or hook of Hamate

bones in hand and wrist

27 total bones in each hand/wrist 1. 14 phalanges - fingers - long bones 2. 5 metacarpals - palm - long bones 3. 8 carpals - wrist - short bones

wrist arthrogram

demonstration of soft tissue structures of the wrist joint proper performed with contrast medium

2nd CM joint

gliding joint - formed by 2nd metacarpal and trapezoid/lesser multangular

3rd CM joint

gliding joint - formed by 3rd metacarpal and capitate/Os Magnum

4th/5th CM joint

gliding joint - formed by 4th/5th metacarpal and hamate/unciform

distal phalanx

has a flattened, spatula appearance, a rough rounded rim for insertion of the finger nail

carpal bridge

posterior surface of the carpal bones - convex

1st CM joint

true saddle joint - formed by 1st metacarpal and trapezium/greater multangular movements include: flexion, extension, abduction, adduction, circumduction