Thoracic Limb Module Learning Issues Flashcards
Carpal Joints
Radiocarpal Joint, Middle Carpal Joint, Carpometacarpal joint
Joint Pouches Carpal Joints
Radiocarpal joint and Middle Carpal joints both have dorsal and palmarolateral joint pouches
clinical access carpal joints
normally access radoiocarpal and middle carpal joints on the dorsal aspect on on either side of tendon fo extensor carpi radialis with limb held in flexion
carpal effusion or laceration to dorsal aspect carpus may
access palmarolateral aspect of joints
palmarolateral access radoiocarpal joint and middle carpal joint
palpate tendons of lateral digital extensor and long tendon of extensor carpi ulnaris when horse is standing, following these tendons distally until they form V with extensor retinaculum; small depression 1/2 to 1 cm to this V is where we place needle perpendicularly palmarolateral pouch middle carpal joint is about 1 inch below where we access palmarolateral pouch radiocarpal joint
carpometacarpal joint access
treated via its communication with the middle carpal joint they communicate the majority of the time except in cases of severe osteoarthritis when bony proliferation blocks this communcaiton
flexion of carpus due to
movement in radiocarpal joint and middle carpal joint; in normal horse should be able to bring digit to elbow without causing discomfort
during flexion bc of inter carpal ligaments btwn carpal bones
intermediate carpal bone moves proximally in relation to radial carpal bone; important in interpretation of flexed lateral view of carpus
extensor surface of the carpus
dorsal aspect (any tendon that crosses this surface will be an extensor of this joint when its muscle contracts)
flexor surface of the carpus
palmar aspect (any tendon that crosses this surface will be a flexor of this joint when its muscle contracts)
Flexors of the carpus
no grooves for flexor tendons like there is for extensors; SDF, DDF, Flexor carpi ulnaris, flexor carpi radialis
carpal flexor proximal attachments
medial epicondyle of the humerus
flexor carpi radialis
located medially and sits right against the radius
flexor carpi ulnaris
located laterally (like the ulna)
Flexor cari radialis tendon distal attachment
proximal aspect of medial splint bone (metacarpal 2) (mirrors long tendon of extensor carpi unaris on lateral side)
flexor carpi ulnaris tendon distal attachment
accessory carpal bone; short tendon of extensor carpi ulnaris also attaches to accessory carpal bone
superficial digital flexor tendon distal attachments
has attachment points P1 and P2
deep digital flexor tendon distal attachments
- DDF has multiple heads of origin
- distal attachments on palmar aspect of P3
DDF and SDF share
common carpal synovial sheath and course through carpal canal
carpal canal
defined as a tunnel
- floor of tunnel= palmar carpal ligament
- roof of tunnel= flexor retinaculum
palmar carpal ligament
runs along palmar aspect of carpal bones to prevent overextension
what travels through carpal canal
SDF, DDF, median artery and vein, median and ulnar nerves
median and ulnar nerves in carpal canal
will branch and form medial and lateral palmar nerves
extensors of carpus
cr -> L extensor carpi radialis, common digital extensor, lateral digital extensor extensor carpi ulnaris,
extensor carpi ulnaris distal attachment
Short tendon- accessory carpal bone
long tendon- travels through groove on accessory carpal bone to attach on proximal aspect of 4th metacarpal bone
common digital extensor distal attachment
common digital extensor tendon travels through groove on radius attaches to P1, P2, P3 distally
extensor carpi radialis distal attachment
tendon travels through groove on radius to proximal tuberosity of metacarpal three
lateral digital extensor distal attachment
proximal P1 with common digital extensor
proximal attachment carpal extensors
lateral epicondyle of the humerus
lateral styloid process of radius
has shallow groove for tendon of lateral digital extensor
extensor carpi ulnaris is
actually a flexor of the carpus because of its attachments of the accessory carpal bonanza lateral splint and it crosses flexor surface of carpus but its grouped with extensors because shares innervation of radial nerve and shares proximal attachments and was evolutionarily an extensor
what innervates extensors of carpus
radial nerve
tendon sheaths and carpal extensors
all tendons have associated tendon sheaths except short tendon of extensor carpi ulnaris which goes to accessory carpal bone
(aka tendon of extensor carpi radialis, tendon of common digital extensor, tendon of lateral digital extensor, and long tendon of extensor carpi ulnaris)
tendon sheaths of extensors of carpus can
get distended because of excess synovial fluid and cause distinct swellings on the limb
flexor carpi radialis has
a tendon sheath which runs through canal formed with flexor retinaculum
who has tendon sheaths
SDF, DDF, Flexor carpi radialis, extensor carpi radialis, common digital extensor, lateral digital extensor, long tendon of extensor carpi ulnaris
think of carpus as having
8 different surfaces
4 simples are dorsal and palmar surfaces and lateral and medial sufaces
4 others are dorsolateral, dorsomedial, palmarolateral surface, and palmaromedial surface
view is named from
direction of X-ray beam to where plate is sitting
things in profile
ie things we can see will be opposite then the name of the view
DP view of the carpus position to shoot
person holding beam source on dorsal aspect plate positioned on palmar aspect of the carpus
lateral to medial view of carpus
person holding beam source on lateral side of limb and x-ray beam directed through the carpus to plate on medial aspect of purpose
what do you see on DP view of carpus
see lateral and medial surface of carpus; can see lateral surface of radius including styloid process and lateral aspect of some carpal bones and same holds true for medial surface (medial styloid process of radius and medial surface of some carpal bones)
what do you see on lateral to medial view of carpus
dorsal and palar surfaces of carpus
accessory carpal bone DP view
completely superimposed over radius and proximal row of carpal bones in this view
accessory carpal bone dorsal palmar view
this is the one view where you can see the accessory carpal bone not summated on any other bones
DLPMO stands for
dorsolateral palmaromedial oblique
DLPMO positioning to shoot
xray beam source positioned on dorsolateral aspect of surface and plate sits on palmaromedial surface
what surfaces do you see on DLPMO view
see dorsomedial and palarolateral surfaces in profile
what does DMPLO stand for
dorsomedial palmarolateral oblique
positioning DMPLO
xray beam source positioned on dorsomedial surface and plate sits on palmarolateral surface
what surfaces do you see on DMPLO
Dorsolateral Palmaromedial surfaces
chip fractures seen in DLPMO view
these are located on doromedial surface of radius, proximal and distal rows of carpal bones
accessory carpal bone DLPMO view
looks like baseball catchers hit in this view on palmarolateral surface
what bones do you see on DMPLO
bones on dorsolateral and palmaromedial aspects of carpus
- 2nd carpal bone (on palmaromedial surface); in this view not imposed on other carpal bones; this articulates forms lower case t;
what bones do you see on DMPLO
bones on dorsolateral and palmaromedial aspects of carpus
- 2nd carpal bone (on palmaromedial surface); in this view not imposed on other carpal bones; this articulates forms lower case t
- dorsolateral surface of the radius and rows of carpal bones
How to tell 4th carpal bone vs 2nd carpal bone articulations apart
4th carpal bone articulation you see on DLPMO view forms uppercase t
2nd carpal bone see on DMPLO making lower case t
flexed lateral view
limb held in flexion and x ray beam source on lateral aspect of limb and plate on medial aspect of the limb
skyline views
take to see more dorsal aspect of carpal views
- can take skyline of proximal or distal row of carpal bones
why take flexed lateral
when flex limb the intermediate carpal bone moves proximal to radial carpal bone can use this to further define where location of chip may be on either of these bones
other name for skyline views
dorsoproximal to dorsodistal oblique views
how to hold for skyline
horses limb held in flexion this time plate on dorsal aspect of cannon bone and xray beam is shot downward; angle of xray beam dictates if you are shooting through proximal or distal row of carpal bones
