Hand and Wrist Test 2 Flashcards
The wrist complex has how many degrees of freedom?
2
biaxial
What carpal bones form the proximal radiocarpal joint?
Scaphoid, Lunate, Triquetrium
they attach to the radial head and tfcc
How is the end of the radius angled?
volarly (palmarly) and ulnarly/medially
What carpal articulates with the TFCC
Triquetrium
what carpals articulate with the end of the radius
medially-lunate
laterally-scaphoid
what is the function of the pisiform?
increases movement arm for flexor carpi ulnaris
what ligaments connect the proximal carpal row?
scapholunate interosseous and lunotriquetral interosseous ligaments
TFCC is Connected proximally via dorsal and volar radioulnar ligaments
the Distal radiocarpal segment is ___________ than proximal segment → incongruent joint!
sharper
The scaphoid and lunate receive ___ of axial load , the TFCC receives __
80%
20%
Keinböck’s disease = you have a ______ ulna + there is lack of blood supply to the _______
Short
Lunate
Most ligaments and muscles that cross radiocarpal joint also contribute to stability of midcarpal joint
FCU is the exception - because it attaches to _________, ________, and _________
5th metacarpal, hook of the hamate, and pisiform
so i guess it does not contribute to joint stability
What carpal bones are in the distal row?
Trapezium, trapezoid, capitate, and hamate
Note: the carpals move almost as a fixed unit, with equal distribution of loads across articulations with proximal row
Dorsal wrist ligaments can be described as….
Volar/palmar ligaments of the wrist can be described as…
Dorsal- thin
Volar- thicker stronger
Extrinsic carpal ligaments do what
connect the carpal bones to other bones
Scapholunate interosseous ligament does what?
Lunotriquetral interosseous ligament?
Maintains scapho-lunate stability
Maintains lunate-triquetral stability (star by this one on the slide for some reason i guess it’s important)
The Dorsal radiocarpal ligament
and Dorsal intercarpal ligament do what?
Together form “horizontal V” to stabilize scaphoid during wrist ROM
They both attach to triquetrium
They come tight in wrist flexion!
Dorsal radiocarpal ligament function
Possibly helps to offset sliding of proximal carpal condyle on inclined radius
What carpal bone is considered the keystone of the wrist?
capitate
it is thought to be center of wrist rotation
contacts 7 other bones.
What bones articulate with the capitate?
Scaphoid
Lunate
Hamate
Trapezoid
2nd metacarpal
3rd metacarpal
4th metacarpa
What bones do not? Pisiform, trapezium, triquetrium
1.From full flexion, wrist extension begins with the distal row ___________ on the proximal row
2.Then distal row and _________ move on lunate and triquetrium to 45 deg when scaphoid and lunate lock
3.finally proximal row extends on radius/disc to fully extend close-packed position
1.gliding posterior
This is the sequence to neutral
2.Scaphoid
Note: flexion is opposite sequence
In radial deviation: Carpals all slide _________ on radius with _____ of proximal row and _____ of distal row. Close-packed position.
Ulnarly
Flexion of proximal row
Extension of distal row
In ulnar deviation:
The carpals slide ______ and proximal row ______ and distal row _________
Ulnarly
Proximal - extends
distal row - flexion
When wrist is extended you have very little _____ (closed packed position)
_______ is the loosed packed position
deviation
Flexion