wrist Flashcards
The main functions of the wrist complex are to
Position the hand in space for prehension
Control the length-tension relationships in multiarticular hand muscles
Control fine adjustments of grip
what are the joints of the wrist
Distal RU Joint
Radiocarpal Joint – Wrist Joint
Intercarpal Joints(Midcarpal)
Carpometacarpal Joints
Intermetacarpal Joints
Radiocarpal Joint is between what
This is the joint between the distal aspect of the radius and articular disk proximally and the proximal row of carpal bones distally
Radiocarpal Joint - what kind of joint
synovial - ellipsoid (condyloid
proximal part of the radiocarpal joint
Radius & Articular Disk
distal part of the radio ulnar joint
Scaphoid, Lunate, Triquetrum
distal part of the radiocarpal joint
Scaphoid, Lunate, Triquetrum
movement allowed at the distal radiocarpal
Flexion/ext, add/abd, & circumduction
Ulnar deviation
pinky side
at the radiocarpal joint
radial deviation
thumb side
at the radiocarpal joint
radial inclination
Distal radial surface is approximately 23° inclined off the perpendicular to the radial shaft
Difference in length between the ulnar head and the tip of the radial styloid is an average of what
12 mm (limits radial deviation)
ulnar variance
The difference in length between the ulnar head and the distal radius
Ulna positive
ulna extends further toward the carpals
ulnar variance
Ulna neutral
ulnar variance
when they are approximately even
ulna negative
ulnar variance
when the radius extends further toward the carpals
Colles Fracture
The most common wrist fracture-
distal radius fracture - distal radial metaphysis
Closed fracture
Usually occurs within 2 cm of the articular surface
what happens in Colles Fracture
the apex of the distal fragment points in the palmar direction and the hand and wrist are dorsally displaced.
what population do we see colles fracture in
adults
rare in children
Distal radiocarpal joint vex or cave
vex
Scaphoid, lunate, triquetrum
proximal radiocarpal joint - vex or cave
cave
radius and the articular disc
Triangular fibrocartilage complex (TFCC) is made out of
Consists of articular disk, distal radio-ulnar ligaments, meniscus homolog, ulnolunate and ulnotriquetral ligaments, extensor carpi ulnaris sheath, and ulnar capsule
Triangular fibrocartilage complex (TFCC) function
interposes between the distal ulna and carpus (force-transmitting and stability)
axial loading in the radius and the ulna
TFC and ulnar side - carries 20% of axial loading across the wrist
Radial side carries 80% of axial load
TFCC variation
varies inversely with ulnar variance,
EX: ulnar negative wrists have a thicker disk
Compressive forces go through:
Capitate
Scapholunate junction
Distal radius
TFCC
Removal of TFCC reduces load on what and by how much
ulna by 12%
Increase in ulnar negative variance may cause what issue in the carpals
avascular necrosis of Lunate (Keinbocks Disease)
Avascular necrosis of the lunate is called what
Kienbock’s disease
Kienbock’s disease characteristics
Affect young adults
men
Related to repetitive trauma (martial arts, handball, volleyball)
Ulnar negative variance is a risk factor
Radiocarpal - fiborus Capsule
Fibrous capsule from distal radius and ulna to proximal row of carpal bones, lined by synovial membrane
Radiocarpal - fibrous Capsule Strengthen by what
Rad/uln carpal ligs. (palmar)
Collateral ligs (dorsal)
Radiocarpal Ligaments
Dorsal RC
Dorsal UC
Ulnar Collateral-
Radial Collateral-
Volar RC
Volar
Ulnocarpal
Radiocarpal - Blood
articular arteries from dorsal and palmar carpal arterial arches.
Radiocarpal - Blood and Nerve Supply
from anterior interosseous branch of median n., posterior interosseous branch of radial n., and dorsal and deep branches of ulnar nerve
Intercarpal Joints
In between each neighboring carpals
Midcarpal Joint
Pisotriquetral Joint
Intercarpal Joints what kind of jts
Plane synovial; sliding movements
Sliding movements help wrist flexion and radial dev.
Scaphoid details
Transmit majority of forces; at risk for fracture at the wrist – Radial collateral ligament attaches and provides vascular supply
Scaphoid is over 80% covered with articular cartilage
Lunate details
Most frequent dislocated; vasculature
supplied by dorsal and volar lig.
Triquetrum details
Attach UCL
Pisiform
attachment for retinacula, ligaments (UCL), and
tendons (flexor carpi ulnaris & AbDM)
Blood supply of the scaphoid
Dorsal scaphoid branch: proximal 70% to 80% of bone
Volar scaphoid branch: distal 20% to 30% of bone
Tenuous blood supply to proximal pole explains the delayed union of fractures
Scaphoid fracture
Common in young (15 to 30 yo), rare underage of 10; however, accounts for over 70% of carpal fracture in children
FOOSH - common mechanism of injury
Tenderness over the anatomic snuff box, scaphoid tuberosity (palm), and distal to Lister’s tubercle (dorsal)
Trapezium details
– attachment of transverse carpal lig. and RCL
Capitate details
keystone of the wrist
Hamate
hook offers protection to ulnar artery & n.
what makes up the midcarpal joint
is the joint between the proximal and distal rows of carpals, shown here in this radiograph.
Fibrous capsule in the intercarpal
common articular capsule with a fibrous and synovial layer that covers all of the intercarpal joints together
The only exception is that the joint between the triquetrum and pisiform has its own joint capsule.
Interosseous (intercarpal) ligaments
connecting proximal row carpals
connecting distal row carpals
Palmar intercarpal ligaments
Dorsal intercarpal ligaments
on the palmar and the dorsal side and connect the carpals together
Intercarpal - Blood
articular arteries from dorsal and palmar carpal arches
Intercarpal - Nerve
from anterior interosseous branch of median n., posterior interosseous branch of radial n., and dorsal and deep branches of ulnar nerve
Closed Packed for the midcarpals and the radiocarpal
full extension
open packed for the midcarpals and the radiocarpal
slight flexion
Flex/ext what axis and plane
coronal axis between lunate and capitate; sagittal plane movement
Rad/ulnar dev what axis and pane
sagittal or A-P axis between lunate & capitate; frontal plane movement
Circumduction axis
polyaxial
Flexion artho
anterior (volar) roll, posterior glide: + midcarpal
Limited by dorsal radiocarpal lig
Extension artho
posterior (dorsal) roll, anterior glide: + radiocarpal
Limited by volar radiocarpal and ulnocarpal lig.
Distal carpals glide in the same direction as
the hand rolls
Radial Deviation carpal movement
Distal carpal row moves radially
Proximal row moves toward ulna
Radial Deviation limited by
Bony contact of radius and carpal bones
Stress on the UCL
Radial and ulnar deviation wrist flexed or extended
both limited in extremes of wrist flex and ext due to ligamentous constraints
what has a greater ROM flexion and extension or deviation
flexion and extension
Digits II-V what kind of joint
Plane synovial
sliding movements - cavity is continuous with intercarpal
Digit I what kind of joint
thumb
saddle joint
Ligaments of CMC & IMC 2nd to 5th fingers
Metacarpal Interosseous ligaments
CMC ligaments (trapezium to base of 2nd meta; hamate to 5th meta)
motion in the metacarpals increase in which direction
Motion increases ulnarly
2nd & 3rd: immobile
4th: glide into flex/ext
5th: 10 to 20 degrees flex/add
closed packed for the CMC & IMC ii-v
Closed Pack: full fist
open pack for CMC and IMC ii-v
Open Pack: neutral
CMC of Thumb - Joint Classification
Saddle/synovial; angular movements in any plane
CMC of Thumb - movement
Flex/ext, abd/add, opposition (this is very important)
CMC of the thumb - vex and cave
Concave – flex and ext
Convex – abd and add
injury seen at the CMC of the thumb
High prevalence of osteoarthritis
does the thumb have a seperate joint capsule
yes it is seperate from the rest of the other joint capsules
Fibrous capsule of the CMC of the thumb
Fibrous capsule, loose to allow movement
CMC of Thumb - Movement flexion
53 degrees
CMC of Thumb closed packed
opposttion (pinky to the thumb)
CMC of Thumb - open packed
neutral
CMC of Thumb - Movement ext
42 degrees
CMC & IMC - Blood
Blood – articular arteries from dorsal and palmar metacarpal arteries & dorsal carpal and deep palmar arterial arches
CMC & IMC - Nerve
from anterior interosseous branch of median n., posterior interosseous branch of radial n., and dorsal and deep branches of ulnar nerve “SAME AS RADIOCARPAL, INTERCARPAL
how many tendosn cross the dorsum of the wrist
9
how many tendons that cross the dorsum of the wrist contribute to wrist extesnion
7
7 tendons that contribute to wrist extension
3 primary: ECU, ECRL, ECRB
4 secondary: EDM, EI, ED, EPL
whar two tendons that cross the wrist do not contribute to wrist extension
EPB and APL
Extensor Retinaculum runs from
From distal end of radius to styloid process of ulna, triquetral and pisiform bones
what does the extensor ret form
osseofibrous extensor tunnels
what does the extensor ret prevent
Prevents bowstringing of long tendons during hyperextension
Extensor Tendon Synovial Sheaths
Located in osseofibrous canals
Reduces friction between tendons and walls of canals
Extensor Tunnels at the Wrist:lat to med (Dorsal Compart)
T1- Abductor pollicis longus & extensor pollicis brevis
T2 - Extensor carpi radialis longus & brevis
T3- Extensor pollicis longus
T4- Extensor digitorum & Extensor indicis
T5- Extensor digiti minimi
T6- Extensor carpi ulnaris
APL, EPB (T1) issue
De Quervain’s tenosynovitis
EPL (T3) issue
Rupture at Lister’s tubercle (after wrist fracture)
APL/EPB and ECRL/ECRB (T1 T2) issue
Intersection syndrome
ED, EI (T4)– issue
Extensor tenosynovitis
EDM (T5) issue
Rupture (rheumatoid)
ECU (T6) issue
Snapping at ulnar styloid or tendonopathy
De Quervain’s tenosynovitis
Most common tendonopathy of the wrist in athletes
Inflammation of the tenosynovium of the first dorsal compartment tendons, the APL and EPB
Repetitive wrist motion causes shear stress on the tendons in their small compartment
Common in racquet sports, fishing, and golf
Intersection Syndrome
T1 and T2
Site is tender, swollen, often crepitus during wrist flexion/extension “squeakers syndrome”
Seen in sports requiring forceful repetition of flex/ext
Anatomical Snuff Box ant/rad border
abductor pollicis longus and extensor pollicis brevis (t1)
Posterior/Ulnar border: snuff box
extensor pollicis longus(t3)
Floor: snuff box
scaphoid & trapezium
how many muscles cross the palmer side of the wrist
6 muscles
- produce wrist flexion
primary wrist flexor
FCU and FCR
secondary wrist flexors
FDS FDP PL FPL
Flexor Retinaculum
Thickening of the deep fascia of the forearm
Prevent bowstringing of flexor tendons during flexion
Under constant tension
Aids maintaining the contour of the carpal arch
vincula
The connective tissue that helps hold a tendon down to the bone
Flexor Tendon Synovial Sheaths provide what to the tendons
Protects and nourishes the tendons
Carpal Tunnel Roof
Transverse Carpal Ligament: from trapezium/scaphoid to hamate/pisiform
Floor of carpal tunnel
Palmar Carpal Arch
Contents of carpal tunnel
Median nerve
FDS III & IV
FDS II & V
FPL
FDP
Carpal Tunnel Syndrome
Decrease in size of carpal tunnel (inflammation of retinaculum, bone dislocation, arthritis, tenosynovitis) may compress Medial n.
medial nerve innervate what part of the palm
palmar aspect of the thumb, the 2nd finger, the 3rd finger, and the radial half of the 4th finger
what runs through Guyon’s Tunnel
ulnar nerve and art
Guyon’s Tunnel- roof, floor, and walls
Roof: Volar carpal lig.
Floor: Transv. Carpal and pisohamate ligs.
Walls: Pisiform and hook of hamate
