Sx Diseases of the Elbow Objectives Flashcards
List the individual components of elbow dysplasia
Ununited anconeal process (UAP);
Fragmented medial coronoid (FCP);
Osteochondritis dissecans (OCD); and
Joint incongruity
What components of elbow dysplasia are collectively
referred to as “Medial Compartmental Disease”?
Fragmented medial coronoid (FCP);
Osteochondritis dissecans (OCD); and
Joint incongruity.
anconeal and medial coronoid processes are part of this bone
ulna
where the humerus articulates with the ulna
trochlear (semilunar) notch
The anconeal process is the pointy bit at the _____ end of the trochlear notch. The coronoid process is the pointy bit at the _____ end of the notch.
Anconeal is proximal
Coronoid is distal
What is the location on the humeral condyle
where OCD of the elbow usually occurs?
trochlear ridge of the medial humeral condyle
elbow _______ is a mismatch in articular surfaces
incongruity
Elbow incongruity (radioulnar length discrepancy) is part of
the etiology of which two components of elbow dysplasia?
UAP and FCP
How does the phrase “developmental orthopedic disease” apply to
patients with elbow dysplasia? What does this have to do with
“biphasic age distribution”?
Developmental orthopedic disease is one that first manifests prior to skeletal maturity
Even when the lameness seems to resolve, these diseases often lead to secondary effects - joint disease which leads to DJD in the long run
When patients present later in life it is due to the secondary effects of the disease rather than the primary issue = Biphasic age distribution
For joint‐related developmental orthopedic diseases, the rule
“biphasic, bilateral, and heritable” always applies.
T/F:
Elbow dysplasia is hereditary
TRUE!
(so do not breed!)
Describe a typical patient with elbow dysplasia
elbow dysplasia is a developmental orthopedic disease so:
YOUNG, male, large/giant breed dogs
Is elbow dysplasia usually unilateral or bilateral?
Usually unilateral, but 35% of cases have bilateral disease, so it’s common!
. Describe the typical history of a dog with elbow dysplasia
chronic, progressive lameness.
It may be intermittent, only showing up after activity,
especially in the early phases.
How can bilateral elbow dysplasia mask lameness?
It will manifest not as lameness
but rather more as activity intolerance.
Younger dogs will still want to play and run, so difficult for owner to recognize
Describe the PE findings typical of elbow dysplasia
Gait exam (down on the sound) identifies the problem limb
Effusion in the elbow and pain on elbow manipulation
identifies the elbow as the source of the lameness
If chronic, may feel crepitus during ROM (because effusion leads to fibrosis)
What is the characteristic posture of dogs with elbow dysplasia?
Stand with their toes pointed out at an angle while holding
the elbow in toward the body (adduction)
All of these postural changes serve to help offload the painful
medial side of the joint, and shift the weight toward the lateral side.
Describe the proposed cause of UAP in general terms
elbow incongruity causes abnormal stresses on the developing anconeal process prevent it from fusing
What is the difference in ossification pattern of the ulna
between breeds susceptible to UAP and those that are not?
There is a separate center of ossification in the anconeal process
in breeds affected by UAP.
This center of ossification is not present in breeds that aren’t affected by UAP
The anconeal process is normally fused to the ulna by
___ weeks
20 weeks
What type of radiograph is necessary for diagnosis of UAP?
You need a flexed lateral view of the elbow to diagnose UAP
If the anconeal process remains separate from the ulna at ____ weeks,
it will not go on to fuse later, and is considered UAP!
24 weeks
What is the proposed etiology of FCP?
incongruity, as might happen with a shortened radius, is responsible for
microtrauma, which results in chronic overloading of the coronoid process
What are some radiographic findings in an animal with
UAP? What type of rad is required to see it?
Flexed lateral elbow rad
Note the line of separation between the relatively large anconeal fragment and the underlying ulna
any separation between the anconeal process and the ulna at 24 weeks of age or later is pretty much a slam dunk diagnosis
KNOW THIS!!!
What are some radiographic findings in an animal with
OCD? What type of rad is required to see it?
well‐positioned craniocaudal view of the elbow
a defect or divot in the bone of the joint surface which corresponds to a thickened section of articular cartilage
Sclerosis of the subchondral bone (manifests as bone that is whiter, or denser, than normal)
Describe the finding of OCD on the radiograph
white arrow in the left image points out a
small divot in the distal joint surface of the medial humeral condyle.
black arrow points to sclerosis
in the subchondral bone deep to the defect.
(The right image is much more subtle. If I ask you to identify an OCD lesion on an exam it will be based on a lesion more like the left image than the right.)
Are radiographs useful in identifying FCP?
NOPE, not really! If you can, will probably see on the lateral view
Standard craniocaudal and lateral views, sadly, aren’t terribly useful in identifying FCP.
The coronoid region of the ulna overlaps other portions of either the radius or the ulna.
Flexing the elbow doesn’t help you particularly, as this positioning doesn’t do anything to set the coronoid off from the rest of the elbow as it does for the anconeal process.
Describe the findings consistent with FCP on the lateral radiographs
A: medial coronoid process with indistinct margins
B: flattening of the medial coronoid
C: irregular margins
(D) is simply illustrating osteophytes in the region of the medial coronoid, which would occur once the secondary degenerative changes occur
What is the use of CT in the diagnosis of elbow dysplasia?
CT can be used to diagnose any of the four components of elbow dysplasia. Technically it is the least invasive way to do so, and is extremely reliable in diagnosing FCP.
What is the role of arthroscopy in evaluating a joint for elbow dysplasia?
Arthroscopy gives the surgeon a comprehensive view of all of the joint surfaces
Incongruity can be diagnosed arthroscopically as well
As noted before, it also gives the surgeon the ability to treat the pathology – diagnosis and therapy rolled into one.
What are the 2 most common treatments for UAP?
What are the indications for each?
Fragment excision (older dog with DJD)
Osteotomy + Fixation* (younger dog)
How does the Osteotomy + Fixation approach
address the role of incongruity in UAP?
Osteotomy allows distraction of the ulna and restoration of congruity because the ulna lengthens which encourages union of the
anconeal process
What is the typical treatment protocol for OCD and FCP?
Arthroscopic treatment is GOLD STANDARD!
(Fragment removal and debridement of lesion bed so it fills in)
Can also do an Ulnar Osteotomy as adjunct for FCP
+anti-inflammatories long term
What is the prognosis for elbow dysplasia?
Early intervention is the best chance for a good prognosis,
but early intervention DOES NOT prevent DJD!
Which is better for treatment of elbow dysplasia?
Arthrotomy or Arthroscopy
ARTHROSCOPY!
Why is simple fragment excision for treatment of UAP
not sufficient by itself?
because the instability will still remain
T/F:
Typical treatment for FCP and OCD is often combined with treatment for incongruity
TRUE!
The failure of union between the medial and lateral portions of
the humeral condyle is known as
IOHC- Incomplete Ossification of the Humeral Condyle
What is the breed predisposition of IOHC?
SPANIELS, males
What are the three ways IOHC might present?
No clinical signs
Mild weightbearing lameness that is worse after activity
Acute non-weighbearing lameness indicative of a pathologic fracture
Describe radiographic features of IOHC
Diagnosis of IOHC requires demonstration of the condylar fissure. This can usually be achieved with high quality craniocaudal radiographs of the elbow,
The fissure may be partial, only extending partway to the supratrochlear foramen, or it may be complete, extending all the way. It is important that IOHC is not mistakenly diagnosed on the basis of seeing a mach line – a visual anomaly created by the superimposition of one bone edge on another, which can appear as a radiolucent line through the condyle.
What is the importance of assessing the contralateral limb in IOHC?
90% of cases are BILATERAL!!!
why is medical therapy is contraindicated for IOHC?
IOHC is not responsive to medical treatment
What is the surgical recommendations for IOHC?
If NO fracture: Single large lag screw only!
Otherwise treat fractures based on configuration
(medial or lateral- lag screw and antirotational wire)
(T or Y fracture- plate application)
What is the prognosis for IOHC?
EXCELLENT
How is the elbow stabilized in flexion normally?
Collateral ligaments
How is the elbow stabilized in extension normally?
Olecranon
T/F
Elbow luxation requires disruption of at least one collateral ligament
TRUE
How is elbow luxation named?
by the distal component
___% of elbow luxations are LATERAL
90%
What type of radiograph is necessary to diagnose elbow luxation?
Craniocaudal
What are the indications for a closed-reduction of an elbow luxation?
If it is an acute luxation of a normal stable joint
What are the indications of open-reduction of elbow luxation?
Concurrent fractures
unsuccessful closed reduction
unstable joint
recurrent luxations
How do you assess the health of the collateral ligaments
following reduction (Campbell’s test)?
Elbow and carpus at 90°, then try to pronate and supinate the limb
Supination- lateral collateral
Pronation- medial collateral
Why must the limb be maintained in extension
following closed reduction of elbow luxation?
So the olecranon can provide stability and give the
collateral ligaments a chance to heal
What methods of coaptation can be used following
elbow reduction?
Splica splint
Flexible ESF
What is the prognosis for closed reduction of elbow? For open reduction?
Closed = EXCELLENT
Open = Fair
There are ____ types of congenital elbow luxations
3
What is the most common type of congenital elbow luxation?
Type 2
lateral rotation of the ulna with subluxation of the radius
What is the typical signalment for Type 2 congenital elbow luxation?
Small breed dogs noted soon after birth
Partial flexion, internal rotation of the antebrachium
What is the prognosis for congenital elbow luxation
Guarded to Fair
Normal joint function NOT expected
T/F:
The CUE elbow salvage procedure is appropriate only for
joints with lateral disease
FALSE!
CUE is for MEDIAL joint disease only
What are the limitations of the TER (Total Elbow Replacement)
salvage procedure?
Technically challenging and costly
Potentially catastrophic- amputation or arthrodesis
Fracture joint luxation and infection implant loosening complications
Functional outcome is suboptimal
Describe arthrodesis of the elbow
Complete fusion of the elbow joint at a standing angle
Results in limited function and peg leg
