Hand and Wrist

when does the triquetrum articulate with the radius

in ulnar deviation

what percentage of compression forces pass through the scaphoid/lunate to radius

80%

what bones make up the radiocarpal joint

lunate, scaphoid, triquetrum*, radius

which is the primary forearm bone articulating with the carpals

radius

what is the midcarpal joint complex

articulation between proximal and distal rows of carpal bones

what are the 2 compartments of the midcarpal joint complex

medial and lateral compartments

how many intercarpal joint articulations are there

13

is there more motion at the medial or lateral midcarpal joint compartment

medial

are the distal or proximal carpals convex in the medial compartment of the midcarpal joint

distal

are the distal or proximal carpals convex in the lateral compartment of the midcarpal joint

proximal

what do wrist ligaments maintain

natural intercarpal alignment and transferring forces across the wrist

what do mechanoreceptors in the wrist ligaments do

contribute to proprioception, reflexively protect the wrist

what are the two types of wrist ligaments

intrinsic and extrinsic

what does the capsule surround

wrist and distal radioulnar joint

dorsal radiocarpal ligament attachments

distal radius to lunate and triquetrum

palmar and dorsal radiocarpal ligaments are major contributors to

arthrokinematics

radial collateral ligament attachments

radial styloid to scaphoid

radial collateral ligament is considered to be a

thickening of the lateral capsule

dorsal radiocarpal ligament has rich ___ ___

sensory innervation

does the palmar or dorsal radiocarpal ligament have greater stability

palmar

palmar radiocarpal ligament is made up of how many ligaments

3

when is the palmar radiocarpal ligament maximally taut

full wrist extension

what are the five stuctures of the TFCC

articular disc

dorsal capsular ligament

palmar capsular ligament

palmar ulnocarpal ligament

ulnar collateral ligament

what sits in the TFC

head of ulna

what is the function of the TFCC

bind radius and ulna while permitting pronation and supination

what is the triangular fibrocartilage

articular disc forming structural backbone

what forms walls around the triangular fibrocartilage

palmar and dorsal capsular ligaments

where does the palmar ulnocarpal ligament originate from

palmar capsular ligament

is palmar ulnocarpal ligament extrinsic or intrinsic

extrinsic

ulnar collateral ligament is a thickening of

the medial capsule

what does the ulnar collateral ligament support

medial portion of the wrist

is the ulnar collateral ligament extrinsic or intrinsic

extrinsic

ulnar collateral ligament has substantial ___ to allow hand to ___ during __ and __

flexibility; rotate; pronation; supination

types of intrinsic ligaments

short, intermediate, long

what do the short intrinsic ligaments connect

distal row of carpal bones

what do the intermediate intercarpal ligaments connect

distal-proximal or proximal-proximal

what do the long intrinsic ligaments connect

palmar and dorsal intercarpal ligaments

what ligament is the ultimate lunate stabilizer

scapholunate

what is an example of an intermediate intrinsic ligament

scapholunate ligament

what are the two types of long intrinsic ligaments

palmar and dorsal

palmar long ligaments form a

V Shape

what do the palmar long ligaments do

guide arthrokinematics

what happens if the dorsal long ligaments are torn

results in instability

what happens if the scapholunate ligament is injured

bad for wrist motion and wrist stability

what is the orientation of the dorsal long ligaments

horizontal

what is the keystone for the proximal transverse arch

capitate

what is the keystone for the distal transverse arch

metacarpals 2 and 3

where is the proximal transverse arch

distal row of carpal bones

where is the distal transverse arch

metacarpophalangeal joints

what is the keystone of the longitudinal arch

metacarpals 2 and 3

where is the longitudinal arch

curve of 2nd and 3rd rays

where is the transverse carpal ligament connected to

pisiform, hook of hamate, scaphoid, trapezium

what does the transverse carpal ligament convert

palmar concavity into carpal tunnel

what does the transverse carpal ligament prevent

bowstringing of tendons out of carpal tunnel

what type of joint is the wrist

condyloid/ellipsoid

how many degrees of freedom does the wrist have

2

is there rotation at the wrist

no - forearm permits pronation and supination

what limits radial deviation

ulnar tilt of distal radius

what is our axis of rotation for A/P and M/L

through capitate

what motion is extension naturally combined with

radial deviation

what motion is flexion naturally combined with

ulnar deviation

what are the two articulations we look at for wrist arthrokinematics

lunate-radius and capitate-lunate

wrist arthrokinematics flexion/extension

convex on concave

wrist flexion roll and slide

palmar roll dorsal slide

wrist extension roll and slide

dorsal roll palmar slide

is lunate or radius moving in flexion/extension

lunate

is capitate or lunate moving in flexion/extension

capitate

the two wrist articulation we look at have ___ arthrokinematics but we describe them as two different joints

same

during flexion and extension, both wrist joints have ___ and ___ motion across joints

synchronous; equal

what is the close packed position of the wrist

full extension

is the close packed position the position of most joint congruency

no

ulnar and radial deviation arthrokinematics

convex on concave

ulnar deviation roll and glide

ulnar roll radial glide

radial deviation roll and slide

radial roll ulnar slide

what bones are moving on the radius during ulnar deviation

lunate, scaphoid, triquetrum

how much motion is coming from the midcarpal joint during radial deviation

85%

why is the majority of motion coming from the midcarpal joint during radial deviation

due to the ulnar tilt of radius

what happens to the proximal carpals during ulnar deviation

they extend slightly

how much does the scaphoid extend during ulnar deviation

20 degrees

what happens to the proximal carpals during radial deviation

they flex slightly

how much does the scaphoid flex during radial deviation

15 degrees

what ligaments tense during ulnar deviation

palmar ulnocarpal and lateral palmar intercarpal ligaments

what ligaments tense during radial deviation

palmar radiocarpal and medial palmar intercarpal ligaments

why do different distal and proximal lateral and medial ligaments tense during ulnar and radial deviation even though they have the same arthrokinematics

roll and slide proportions are different - distally there is more roll and proximally more slide

CMC joints 2-5 are surrounded by

articular capsules

what surrounding structures strengthen CMC joints 2-5

- dorsal carpometacarpal ligament

- palmar carpometacarpal ligament

- intermetacarpal ligament

what carpal bone does the 2nd metacarpal articulate with

trapezoid and a little capitate and trapezium

what carpal bone does the 3rd metacarpal articulate with

capitate

what carpal bone does the 4th metacarpal articulate with

hamate and capitate

what carpal bone does the 5th metacarpal articulate with

hamate

what type of joint is the 1st CMC joint

saddle

what two motions combine to make opposition of the thumb

abduction and flexion

do CMC 2/3 or 4/5 have more flexion and extension ROM

4/5 - 25-45 degrees

what type of joints are CMC 2-5

varies

how many DOF does CMC 1 have

2

what plane is thumb abduction

sagittal

what plane is thumb flexion and extension

frontal plane

CMC 1 abduction/adduction arthrokinematics

convex on concave

CMC 1 abduction roll and slide

palmar roll, dorsal slide

CMC 1 adduction roll and slide

dorsal roll, palmar slide