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Elbow
Dysplasia in Large Dogs
Elbow
dysplasia is a common cause of forelimb lameness in large and giant
breed dogs. Breeds that are overrepresented include the Labrador
Retriever, Golden Retriever, Chow Chow, Rottweiler and Bernese Mountain
Dog. 
Elbow
dysplasia includes a group of specific diseases, including primary
incongruency of the elbow joint, fragmented coronoid process (FCP),
ununited anconeal process (UAP), and osteochondrosis (OCD) of the
humeral condyle. The common themes surrounding this group of diseases
are that they all appear to have both a genetic and environmental
influence, and all will ultimately lead to the development of degenerative
joint disease (DJD).
Clinical
signs related to elbow dysplasia most commonly occur in the young,
rapidly growing large breed dog. Forelimb lameness, sometimes bilateral,
is usually observed by the client. The client often times mistakes
the lameness for a sprain. A stiff, stilted gait is often observed,
along with pain noted upon manipulation of the elbow joint, especially
in full extension. With severe cases, marked elbow effusion is often
noted both on palpation and visual observation. With onset of moderate
to severe DJD, flexion of the elbow is limited by periarticular
fibrosis. In young dogs, the key differentials include the growing
pain diseases including panosteitis and hypertrophic osteodystrophy.
Diagnosis
of elbow dysplasia is most commonly done with orthopedic evaluation
and survey radiographs. An ununited anconeal process shows up readily
on radiographs, and is primarily found in Shepherds. Identifying
a fragmented coronoid process, or condylar OCD lesion is more challenging.
In many dogs, the primary lesion is not seen on routine radiographs,
but secondary signs of DJD are noted. The first radiographic abnormality
we usually see is roughening of the dorsal aspect of the anconeal
process of the ulna. In patients with subtle lameness, or inconclusive
radiographs, advanced imaging may be required, including CT evaluation
or nuclear bone scan. CT evaluation allows in depth examination
of the joint including identification of loose bone fragments, such
as FCP or OCD of the humeral condyle. Bone scintography may be used
to localize the source of pain when forelimb lamness is subtle and
pain cannot be found in the elbow during the orthopedic examination.
Bone scans are economical, easy to perform, and one leg can be compared
with the other to look for hot spots of radioactivity.
Treatment
of elbow dysplasia includes both medical and surgical management.
Medical therapy for elbow dysplasia focuses on minimizing pain and
maintaining a good quality of life. Body weight must be closely
monitored, and if obesity is present, a calorie restricted diet
is prescribed. Conservative management focuses on the use of cartilage
protectants (glucosamine/chondroitin and fatty acid therapy), pain
medications, such as non steroidal antiinflammatories, and occasional
use of narcotics for advanced pain. Most pet food companies currently
provide a joint formula which contains many cartilage friendly products.
Activity is limited to low impact exercises, such as leash walking
or swimming, but some type of exercise is definitely encouraged.
We encourage owners to avoid jumping activities, and any exercise
that requires the stopping, planting and turning activities seen
while chasing balls, agility drills, etc. Consultation with a physical
therapist may also be considered if response to therapy is slow.
Ununited
anconeal processes are still treated with an open approach and surgical
removal of the loose fragment; however the remaining disorders are
treated arthroscopically. Bilateral arthroscopic procedures can
be performed concurrently to minimize patient morbidity and owner
expense. The goals of elbow arthroscopy are to determine the extent
of articular cartilage damage, identify the lesion (FCP, OCD flap),
and remove any loose or diseased bone/cartilage fragments. Most
often, two small portals are created for placement of the arthroscope
and hand instruments. Visualization of the joint is greatly enhanced
using a fiber optic arthroscope. The scope provides magnification
of the articular structures, along with enhanced lighting of the
field of view.
Diseased
bone fragments are removed a variety of ways, including a powered
shaver, small curettes, or small grasping instruments. Arthroscopy
is also able to provide an accurate indicator of long term prognosis
following surgery, based upon the degree and extent of articular
cartilage damage. Often times, the loose fragment of bone within
the joint can cause a large degree of full thickness cartilage damage
along the adjacent humeral condyle. Once the protective cartilage
layer has been worn away, the nerve endings located within the bone
become exposed, and pain ensues. In patients with a large degree
of cartilage loss, prognosis for improved comfort after the surgery
is guarded. Long term medical management is recommended. If we can
safely remove the fragmented coronoid process or OCD flap, and if
the cartilage damage is minimal, then prognosis for improved comfort
after surgery is good.
In
cases where we do not find any loose bone or cartilage fragments,
then we are left with a diagnosis of primary incongruency. Unfortunately,
there is no definitive treatment for incongruency of the elbow.
Corrective osteotomies of the ulna have been performed in an attempt
to smooth the articular surface but results have been unpredictable.
The abnormal wear and tear that occurs with incongruency between
the humerus, ulna and radius is not easily modified, and degeneration
of the joint slowly progresses with time. If incongruency is found,
roughened and abnormal areas of the cartilage can be addressed with
the scope. The scoping procedure is useful in these cases in that
it does provide an accurate diagnosis and prognosis for the owner.
The
take home message for owners of dogs with elbow dysplasia is that
arthroscopy can benefit a large percentage of these patients. However,
we emphasize to the owners that scoping is not a cure all, and continued
medical management is necessary for the majority of the patients
for the remainder of their lifetime.
The
Dallas Veterinary Surgical Center has become one of the leading
referral centers in North Texas for treatment of conditions such
as elbow dysplasia. Please contact one of our surgeons if you have
questions regarding this or any other case case that may benefit
from our services.
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