wrist Flashcards
long bones
metacarpals and phalanges
short bones
carpals
DISTAL RADIUS
tilt of articular surface
dorsal tubercle
~11˚
volar direction F>E
DISTAL ULNA
head (pronation) styloid articulates with TFCC 24˚ ulnar direction UD>RD
Distal radial & ulnar alignment:
Ulna shorter = negative ulnar variance
> radius
> lunate
Triangular fibrocartilage complex
SCAPHOID fracture
most common carpal fracture
the wrist
the junction of the forearm and hand
Movement comes from the radiocarpal, midcarpal & intercarpal joints
joints of the wrist
RADIOCARPAL, midcarpal and intercarpal
radiocarpal joint
•Radius with scaphoid & lunate •TFCC with triquetrum •BIAXIAL ellipsoid joint •Little bony stability GREATER RANGE AT FLX (80) THAN EXTENS. GREATER RANGE IN ADD. (30) THAN ABD. (20)
midcarpal and intercarpal
- Combination of multiple gliding joints
* Complex 3D movements
pisiform
seperate to capsule
Normal wrist movement
requires motion at the radiocarpal, midcarpal & intercarpal joints
carpal bone movements
capable of F / E / RD / UD / sup / pron!
ABD / ADD
midcarpal > radiocarpal movement = More complex movements
•Distal row follows fingers
•Proximal row moves in opposite direction •During ABD the scaphoid flexes to avoid impinging on the radial styloid
Extrinsic ligaments:
Attachment outside of wrist
1. Radial & Ulnar collateral
2. Palmar & dorsal extrinsic ligaments
Palmar much stronger ***
– Palmar radiocarpal resist excessive wrist ext
– Palmar ulnocarpal resist excessive wrist ext
– Dorsal radiocarpal resist excessive wrist flexion
Intrinsic ligaments:
Attach to carpals
• Palmar midcarpal**
• Dorsal midcarpal
• Interosseous between adjacent carpal bones
5 DEDICATED WRIST MUSCLES:
FCR, FCU, ECRB, ECRL ( longer moment arm for radial deviation), ECU
Which bone is most commonly used as the reference in measurement of ROM?
CAPITATE
1ST carpometacarpal (CMC)
M: F-E; ABD-ADD; CONJUNCT ROTN
saddle
2nd – 4th carpometacarpal CMC
gliding
synovial plane
5th carpometacarpal CMC
F-E; ABD-ADD / gliding
synovial saddle
2nd – 5th intermetacarpal
gliding
Synovial plane
1st – 5th MCP
F-E; ABD-ADD /
ellipsoid
1st – 5th interphalangeal (IP)
F-E; ABD-ADD / gliding
synovial hinge
Pinch your thumb & index – what force does it exert on your 1st MCP joint?
Which collateral ligament of the thumb resists this force?
UCL of 1st MCP resists valgrus
collateral ligs. of MCP
radial collateral lig, UCL
- primary stabilisers of MCP joints
transverse carpal ligament / flexor retinaculum
medial/ulnar side: pisiform and hamate
lat/radial side : trapezium
transforms carpal bone arch to enclosed carpal tunnel - provides essential support