The Wrist Complex

Question 1

what two compound joints make up the wrist complex?

Answer 1

radiocarpal
midcarpal

Question 2

The wrist complex contributes to ________ relationship in multiarticular hand muscles and also what?

Answer 2

The wrist complex contributes to length tension relationship in multiarticular hand muscles and also FINE ADJUSTMENT OF GRIP

Question 3

structure and biomechanics of wrist/hand are the same from person to person (true or false)

Answer 3

false: vary from person to person
subtle variations cause differences in way function occurs

Question 4

wrist complex is a ____ joint with ____ degrees of freedom

Answer 4

biaxial joint with 2 degrees of freedom
flexion/extension
radial and ulnar deviation

Question 5

what wrist motions occur in the coronal axis?

Answer 5

flexion and extension

Question 6

in the coronal axis, wrist flexion is __ to ___ degrees

Answer 6

65-85 degrees of flexion

Question 7

in the coronal axis, wrist extension is ___ to ___ degrees

Answer 7

60-85 degrees of extension

Question 8

is there more degrees flexion or extension in the wrist?

Answer 8

More flexion (65-85 compared to extension: 60-85) ((in EEO, wrist flexion is 80, extension is 70))

Question 9

volar/palmar refers to what wrist motion?

Answer 9

flexion

Question 10

dorsal/dorsum refers to what wrist motion?

Answer 10

extension

Question 11

radiocarpal joint is formed by ___ and ____ proximally and ___, _____, ____ distally

Answer 11

proximal radiocarpal joint: radius and TFCC
distal radiocarpal joint: scaphoid, lunate, triquetrum

Question 12

proximal radiocarpal joint segment:
The lateral radial facet articulates with the _____

Answer 12

scaphoid

Question 13

proximal segment: the medial radial facet articulates with the _____

Answer 13

lunate

Question 14

Proximal segment: the TFCC articulates with the _______

Answer 14

triquetrum

Question 15

How is the radius angled at the radiocarpal joint?

Answer 15

oblique and angled volarly in the sagittal plane/ulnarly in the frontal plane

Question 16

TFCC connects medially via ____ and ____ ligaments

Answer 16

TFCC connects medially via dorsal and volar radioulnar ligaments

Question 17

TFCC connects distally to what four things?

Answer 17

ECU tendon
triquetrum
hamate
base of 5th metacarpal

Question 18

In the radiocarpal joint, the proximal carpal row includes what 3 carpals?

Answer 18

scaphoid, lunate, and triquetrum

Question 19

The proximal carpal row is connected by what interosseous ligaments?

Answer 19

scapholunate interosseous ligament and lunotriquetral interosseous ligament

Question 20

The pisiform does not support the radius!
Works as a sesamoid bone to increase the moment arm for which tendon?

Answer 20

Flexor Carpi Ulnaris (FCU)

Question 21

The _____ radiocarpal segment is sharper than the _____ radiocarpal segment (proximal vs. distal)

Answer 21

distal radiocarpal segment is sharper than the proximal segment, making an INCONGRUENT JOINT

Question 22

The scaphoid and lunate receive ____% of the axial load of the wrist

Answer 22

80%

Question 23

The TFCC receives ___% of the axial load of the wrist

Answer 23

20% of the wrist load

Question 24

Is the dorsal radius slightly longer than the volar radius?

Answer 24

YES (tilted volarly)

Question 25

An ulna negative variance means length of the ulna is ____

Answer 25

short

Question 26

radiocarpal joint incongruence and angle of proximal joint surface results in greater range of ____ than _____ (extension/flexion) and radiocarpal _____ deviation (ulnar/radial)

Answer 26

greater flexion than extension, greater ulnar deviation than radial deviation

Question 27

ulnar positive variance means distal ulnar length is _____ compared to radius

Answer 27

long ulna

Question 28

ulnar positive variance is associated with

Answer 28

radial fracture (may surgically use ulnar shortening to decrease pain)

Question 29

ulnar negative variance is associated with what?

Answer 29

avascular necrosis of lunate (keinböcks disease) *due to abnormal force distribution and thicker TFCC

Question 30

ulnar positive variance is often accompanied by ____ impingement

Answer 30

TFCC impingement between distal ulna and triquetrum (thinner TFCC)

Question 31

what muscle crosses the radiocarpal joint but does not contribute to the stability of the midcarpal joint?

Answer 31

FCU: attaches to the pisiform, hook of hamate, base of 5th metacarpal

Question 32

most ligaments and muscles crossing radiocarpal joint also contribute to the stability of the midcarpal joint (true or false)

Answer 32

true except FCU

Question 33

The excursions of the midcarpal joint generally favor range of ____ over ____ (extension vs flexion) and ____ deviation over ____ deviation (radial vs ulnar)

Answer 33

midcarpal: extension over flexion, radial deviation over ulnar deviation, which is opposite of radiocarpal joint

Question 34

What is the midcarpal joint structure?

Answer 34

Articulation between scaphoid, lunate, triquetrum proximally and trapezium, trapezoid, capitate, hamate distally

Question 35

Is the midcarpal joint concave-convex or convex-concave?

Answer 35

CONCAVE-CONVEX

Question 36

true or false: the midcarpals move almost as a fixed unit, with equal distribution of loads across articulations with proximal row

Answer 36

true

Question 37

Are the dorsal or volar ligaments thicker in the wrist?

Answer 37

volar ligaments: thicker and stronger dorsal ligaments: thinner

Question 38

extrinsic ligaments connect the _____ to the radius or ulna proximally or to the metacarpals distally

Answer 38

extrinsic ligaments: carpals to the radius/ulna or to the metacarpals

Question 39

intrinsic wrist ligaments connect the ____ to themselves

Answer 39

carpals intrinsic ligaments are also known as intercarpal or interosseous ligaments

Question 40

true or false: intrinsic ligaments are stronger and less likely to fail but have a slower healing time than extrinsic ligaments

Answer 40

true (book, 276)

Question 41

what are the 3 bands of the volar radiocarpal ligament?

Answer 41

-radioscaphocapitate/radiocapitate -radiolunate/radiolunotriquetral -radioscapholunate

Question 42

what does capitate, the keystone of the wrist carpal bones, touch?

Answer 42

2, 3, 4 metacarpals, lunate, trapezoid, scaphoid, hamate

Question 43

What 3 structures are part of the ulnocarpal ligament complex?

Answer 43

TFCC, ulnolunate ligament, unar collateral ligament

Question 44

what are the extrinsic volar carpal ligaments?

Answer 44

volar radiocarpal ligaments, radial collateral ligament, ulnocarpal ligament compelx

Question 45

what are the intrinsic volar carpal ligaments and what do they do?

Answer 45

scapholunate interosseous ligament-maintain scapho-lunate stability lunotriquetral interosseous ligament-maintain lunate-triquetral stability v-deltoid

Question 46

what are the dorsal carpal ligaments?

Answer 46

dorsal radiocarpal ligament (to triquetrum) dorsal intercarpal ligament-horizontal from triquetrum, lunate, scaphoid and trapezium

Question 47

what do the dorsal carpal ligaments do?

Answer 47

form horizontal V to stabilize scaphoid during wrist ROM become tight in wrist flexion