Equine Stifle Shoulder Elbow

sihirlifil's version from 2017-11-19 16:15


Question Answer
Which radiographic views are taken for the stifle?Cr30*M-CdLO (=Cd60*L-CrMO) for 2 trochlear ridges
Caudocranial (can’t do Cr-Cd!!!)
Cranioproximal-Craniodistal oblique (patella skyline)
What are the weight-bearing surfaces of the stifle?Femoral condyles
How is the LM view taken?Take leg in question back further
Cassette on medial aspect of leg, diagonal, pushed caudally so femoral condyles included
Cassette must be hand held (can’t safely get cassette holder there)
Femoral condyles should be superimposed
Which is the medial trochlear ridge? Lateral?
White: Medial trochlear ridge (bigger & forms right angle)
Yellow: Lateral trochlear ridge
Red = condyles (weight-bearing surfaces!)
Why take a Cd60*L-CrMO?Profile trochlear ridges off one another, show articular & cartilaginous surfaces
How is the Cd60*L-CrMO taken?Cassette: craniomedial to stifle joint (cuddled on inside), parallel with machine
Normal physes of stifle?Distal femur, tibial tuberosity (separate center of ossification)
For a young horse, would you do a LM or ML?ML! Image same as LM, but safer in young horses (can shoot underneath)
Take affected leg forward, profile stifle underneath abdomen
LM view: Arrows?
Left: abdomen
R: Prepuce
May obscure the patella!
How does the LM view of a young foal look?Trochlear ridges irregular, indistinct
How is the CdCr view taken?Leg positioned caudal to other limb & weightbearing
Beam: Directed downwards 10-15* (bc hyperextension of stifle is not horizontal, its oblique)
Cassette: Placed diagonally in front of stifle joint
NORMAL radiolucency due to fossa! Don’t mistake for cyst
Two methods for obtaining the PrCr-DiCrO (skyline patella)?
PrCr-DiCrO view: Arrows?
White: Lateral trochlear ridge
Red: Medial trochlear ridge (bigger)
Patella lies between (OC can occur at cd aspect of the patella, this projection is sometimes taken for that)
On which view can sagittal plane fractures be seen?PrCr-DiCrO (patellar skyline) (swollen stifle, hx of trauma, very lame)
What’s going on here?
NORMAL variations of the fibula due to various ossification centers (pseudofractures)
Abnormalities of the stifleOCD
OC of lateral trochlear ridge
Subchondral lysis, underlying bone & flattening of LTR
Osteochondrosis of left trochlear ridge of femur
Flattening of LTR with irregular surface & separated mineralized osteochondral fragment
What is this arthroscopy image showing?
Large areas of eroded cartilage, can see brown subchondral bone (yellow); NORMAL white smooth cartilage (green)
OC of LTR femur
Severe, extensive irregular surface of length of LTR
Subchondral lysis (red) & extensive subchondral sclerosis (yellow)
Separated mineralized OC fragment (joint mouse) (blue)
Soft tissue swelling
Spot the lesion:
Osteochondrosis of medial trochlear ridge (subchondral lysis)
Subchondral bone cyst (OCLL) of medial femoral condyle
Radiolucent depression extending to articular surface
Dx of these 2 cases? What other diagnostics needed?
Subchondral bone cyst in an adult horse (left) & foal (right) medial femoral condyle
Need to do arthroscopy to figure out if communicating with joint
Subchondral bone cyst in the medial femoral condyle, extending to articular surface
Comminuted sagittal fractures of the patella (3 pieces)
Severity of fracture can only be seen on the CrPrCrDiO projection!
Fracture & DJD (CrCd)
Large smooth bony exostosis on distomedial aspect of femur (white), ST swelling (considerable effusion), medial joint space narrowed
Underlying bone irregular (yellow) suggesting old avulsion fracture at site of medial collateral ligament attachment
What’s F on this US of stifle joint (longitudinal plane)?Anechoic fluid on medial aspect (effusion)
Medial meniscus (MM) is normal!
+---+ = prox end of disrupted medial collateral ligament (completely torn)
What’s going on here?
White arrow = separated avulsed mineral fragment off of medial collateral attachment to distal femur
Yellow arrow = underlying irregularity of distal femur
Yellow arrow?
Ruptured medial meniscus
Arrows? what’s the problem? and what about the dotted line?
OCLL of femoral condyle
Anechoic rim (green) = cartilage
Normal femoral condyles = yellow
Large echolucent depression filled with hypoechoic material
Dotted line = trajectory of needle for injection into cyst (done under GA)


Question Answer
How is the mediolateral view taken?
How is the Craniocaudal view taken?Cassette: Diagonal to get medial aspect of elbow joint, all o f humerus, med & lat portions of radius
What is the CrCd view good for?Comminuted fractures of the ulna
Bone cysts of proximal radius
What’s this? Osteosarcoma in an aged donkey! Never say never! (aggressive lytic lesion of mid radial diaphysis invading the ulna)


Question Answer
How is the mediolateral view taken?Need grid because of muscle mass (gantry system)
Pull leg as far cranially as possible, clear of other shoulder
Trachea highlights the shoulder joint
Osteochondrosis of caudoproximal humerus, showing large subchondral articular radiolucent defect
Guarded prognosis (2ry changes by the time you find it)
Osteochondrosis of proximal humerus
Flattening of curved articular margin
May not be clinically significant