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SUMMER 2009
8500 Arlington Boulevard
Fairfax, Virginia 22031
Tel: 703.752.9100
Fax: 703.752.9200
IN THIS ISSUE:
Shoulder Lameness
Shoulder Lameness . . 1
DR. DAN BREHM, DACVS, SOUTHPAWS SURGERY
News and
Celebrations . . . . . . . . 2
Shoulder Injuries
in Canines . . . . . . . . . 2
Forelimb Lameness . . 3
Cancers of the
Joints . . . . . . . . . . . . . 4
Polyarthritis in Small
Animal Patients . . . . . 5
Shoulder Imaging . . . . 6
Acupuncture for
Shoulder Problems . . 8
Shoulder-origin lameness is a diagnostic
challenge. Localization of the lameness to
the shoulder or the shoulder area during
examination is the “easy” part but additional diagnostics, including advanced imaging, may be needed for precise diagnosis.
Surgery is the treatment of choice for some
shoulder conditions, but many others are
best treated with physical therapy. The
prognosis depends on the specific condition, but there is a generally good chance
of improving comfort and clinical function.
Shoulder-origin lameness can be either
articular or extra-articular, and developmental or acquired. An articular and developmental disorder is osteochondritis dissecans of the proximal humerus. This condition is commonly seen in large to giant
breed, male dogs with signs first seen at 4
to 8 months of age. Most puppies present
with a progressive, variable intensity lameness worsened by activity. On examination,
affected puppies are notably painful on
shoulder extension. Radiographic evaluation (standard lateral view) is often diagnostic, although it is sometimes necessary to
rotate the shoulder internally or externally.
The treatment of choice is debridement of
the articular cartilage lesion with curettage
and microfracture of the subchondral bone.
This procedure can be performed via an
arthrotomy or via arthroscopy. The prognosis is good, with most puppies returning to
normal or near normal function in four to
eight weeks.
Acquired shoulder lameness includes
biceps tenosynovitis, injury to the rotator
cuff structures (in particular, supraspinatus
tendinopathy), and medial shoulder joint
instability. These often occur as athletic
injuries, either from a single event or, more
typically, as a repetitive strain injury. These
conditions frequently do not respond to
NSAID therapy or rest and are worse with
exercise and heavy activity. Supraspinatus
tendinopathy occurs due to repetitive contact of the extended forelimb, as might be
seen with jumping to the ground or fly ball
activities. Most dogs are painful on shoulder flexion and on direct palpation of the
tendon and point of insertion on the
humerus. In chronic cases, mineralization
of the tendon may be seen on radiographs.
The preferred treatment is physical therapy,
with surgical debridement less ideal since
the supraspinatus muscle is an important
passive stabilizer of the joint. Biceps
tenosynovitis also typically occurs as a
repetitive strain injury (in agility dogs and in
at home fence runner dogs), although it
may occur secondary to a degenerative
process rather than an inflammatory one.
Dogs are usually painful on shoulder flexion
with concurrent elbow extension and on
direct palpation over the tendon. The tendon is often thickened/swollen. Physical
therapy is again usually the treatment of
choice, with surgery performed less commonly now given the knowledge that the
biceps tendon does act as a stabilizer of
the shoulder joint. Medial shoulder joint
instability is a recently described entity and
is associated with injury to the medial joint
capsule and medial glenohumeral ligament,
typically occurring as a repetitive strain
injury and associated with concurrent
tendinopathies of the passive stabilizers of
the shoulder. Most dogs resent shoulder
extension and flexion, but are particularly
painful on shoulder abduction. Diagnosis is
based largely on measurement of abduction angles in the sedated dog. Treatment
Continued on page 2
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News And Celebrations
SouthPaws is thrilled to
report that our own Dr.
Jennifer Gieg has published
a paper entitled “Diagnosis
of Ehrlichia ewingii infection
by PCR in a puppy from
Ohio” in the journal
Veterinary Clinical Pathology.
This accomplishment means
that she can now be called
Dr. Jennifer Gieg, Diplomate,
ACVIM (Small Animal
Internal Medicine).
Congratulations Dr. Gieg!
She welcomes your referrals
of both acute and chronic
internal medicine patients. In
addition to standard internal
medicine services, she’s
also qualified in the administration of endoscopicallyinjected transurethral collagen for the treatment of urinary incontinence. Think you
have a patient who may
benefit from this procedure?
Give her a call to discuss it.
On March 29, 2009,
SouthPaws hosted over 250
veterinary technicians, assistants and veterinarians from
Virginia, DC, and Maryland
for our fifth biennial CE
Extravaganza. Six RACEapproved CE credit hours
were awarded to all attendees. Many thanks to our
presenters Drs. Sloan, Toal,
Sheafor, Norton, Yarde,
Clarke, and Khoury, and PT
Carol Wasmucky as well as
to our sponsors Pfizer, Iams
Pet Imaging Center,
Novartis, Merial, Prostora
Max, MWI Veterinary Supply,
Hill’s, and Rx Center for
making this event one of the
best CE events in this area!
Shoulder Injuries in Canines
CAROL WASMUCKY, PT, PET REHABILITATION
Active dogs increasingly suffer from and are diagnosed with shoulder injuries. These injuries
usually involve the rotator cuff muscles, almost always the supraspinatus muscle, often the
infraspinatus muscle, and occasionally the teres minor muscle. The biceps muscle and tendon are also affected due to the location of tendon insertion and force coupling at the shoulder joint. More than 95% of canine shoulder muscular and tendon injuries are successfully
treated with rehabilitation and physical therapy, with the dogs returning to full function without
the need for surgery.
Canine shoulder injuries are usually caused by repetitive activities and triggered by an initial
trauma. This inciting event can occur from jumping off a high wall, hard running or cornering
in pursuit of a Frisbee, ball or felon, or any unusual increase in strenuous activities. The injury
presents as limping or favoring the limb and in some severe cases a significant head bob.
When rest and anti-inflammatory medications are prescribed the limp and other symptoms
may subside, but the limping often reappears with a return to “normal” activity. Rest and medication control the inflammation, but the dog’s strength and endurance continue to decline. It
is at this juncture that the canines need rehabilitation and physical therapy to decrease joint
inflammation, increase muscular strength, and break the cycle. Without this intervention
increased activity causes inflammation, pain and limping, and compensatory movements that
lead to decreased strength and function.
The first of four goals of physical therapy and rehabilitation in both human and animal populations is to decrease pain and inflammation. To do so, ultrasound, massage, electrical stimulation, laser, and ice are used in the clinic, and owners are also instructed how to use gentle
massage and ice at home. To increase range of motion and flexibility, the second rehab goal,
owners are taught how to gently stretch tight muscles, including the bicep and scapular
areas, just as we do in the clinic. To increase strength and endurance (goal three) dog owners
are provided instruction for a daily home exercise program for their dog. The program progresses the patient from easy to more advanced exercises, which is prescribed each week by
the therapist. To accomplish the final rehabilitation goal of returning a dog to full function, the
owner is instructed how to work with the dog off leash, and then advancing them to running,
jumping, and playing.
Behavioral and environmental modifications are also a necessary part of the shoulder rehab
and home exercise program we provide. Owners are counseled on behavioral changes such
as decreasing the dog’s use of stairs, always using a leash to walk the dog, and eliminating
strenuous play, jumping and high-impact activities. Modifying the dog’s everyday environment,
such as putting rugs on hardwood floors and placing a ramp next to the bed or vehicle, are
also important.
We find the pets respond well and the owners are pleased with the progress the dogs display
as a result of our unique rehab program which combines clinical visits and a daily home exercise program. The owners become an active participant in the rehab process and the canines
soon return to playing and pleasing their owners. 䡲
Shoulder Lameness...Continued from page 1
options include physical therapy, arthroscopic radiofrequency treatment, and surgical joint stabilization, depending on the degree of instability. The prognosis is generally good in milder
cases, although the recovery period can be very long.
A final consideration for shoulder lameness is that there are non-orthopedic conditions such
as neuropathies, in particular, peripheral nerve sheath tumors, that can closely match the clinical findings of shoulder-origin lameness. The treatment approach and prognosis are very different for these neuropathy patients. 䡲
continued page 4
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Forelimb Lameness—Could It be Neurologic?
BETSY DAYRELL-HART, VMD, DACVIM (NEUROLOGY), SOUTHPAWS NEUROLOGY
When radiographs of the forelimb of an
animal show joint or bone disease,
diagnosis of lameness seems straightforward, but a clinical presentation of
lameness and muscle atrophy without
abnormal findings on radiographs can
quickly become complicated. Traumatic
avulsion, infarction of the limb, the
nerve roots or the ventral horn of the
spinal cord, lateralizing disc prolapse,
inflammatory disease including GME
and brachial plexus neuritis, neoplastic
and paraneoplastic disease, endocrine
and toxic disorders can all affect nerve
roots and can all cause lameness.
History of lameness includes onset,
progression, duration and response to
symptomatic treatment (rest and NSAID
treatment is often a “first line” treatment
when lameness is acute). Careful
examination will define the lameness. Is
there a problem with only one limb? Is
there any sign of pain in the neck or
upper back? Is proprioception normal?
Are stretch, flexor withdrawal and cutaneous trunci reflexes normal? Is there
any indication of a Horner’s Syndrome?
Is the ipsilateral hind limb normal? Is
there a region of abnormal sensation or
lack of sensation anywhere on the limb?
Unilateral lameness of a forelimb with
muscle atrophy is a “chicken or egg”
problem: Is the atrophy from disuse, or
is muscle atrophy a sign of denervation
or myopathy? Electrodiagnostics can
be very helpful! Electromyography
(EMG) can help to differentiate denervation atrophy from disuse atrophy.
EMG can identify specific muscle
groups that are abnormal, e.g. when
there is focal myositis or muscle injury
causing lameness. Peripheral nerve
stimulation can indicate if one or more
nerves supplying the limb have lost
function, and nerve conduction velocity
testing can help to determine if there is
conduction disturbance without complete denervation. When proximal nerve
roots are affected, CSF will sometimes
reflect disease, e.g., if there is an
inflammatory neuropathy, or even may
diagnose the disease, if it is lymphoma.
Once the area affected and the nature
of the muscle atrophy has been defined,
imaging studies (usually MR, but sometimes CT or bone scans) may be recommended. These procedures require
anesthesia. Often, a subtle lameness
requires a more elaborate diagnostic
plan than does an obvious one.
For example: A 7 year old male castrated mixed breed dog has a 4-6 week
history of limping on the right forelimb.
The dog tends to hold up the right forelimb, but shows no focal pain on palpation or manipulation of the limb. CBC,
chemistry screen, urinalysis and radiographs of the right forelimb are normal. When first examined, the dog was
treated with a NSAID and rested for
about 2 weeks, and lameness lessened
a bit, but overall, it persisted. There is
moderate atrophy of the muscles of the
right forelimb, and scapular muscles
seem more affected than triceps or
biceps. Neurologic exam shows mild
paresis of the right forelimb, subtle proprioceptive deficit of the right forelimb,
and normal to slightly depressed triceps and biceps stretch reflexes.
Sensation is normal on the limb. All
other limbs are normal, and cranial
nerve function is normal.
What’s the best plan for this patient?
EMG is recommended to determine if
muscle atrophy is from denervation (vs.
disuse) and nerve stimulation may be
helpful. CSF tap is recommended along
with electrodiagnostics, to screen for
inflammatory disease of
meninges/nerve roots. When there is a
pattern of denervation, MR scanning
can be scheduled. For disease involving the proximal aspect of nerve roots,
or when the CSF tap has shown abnormality, the scan can focus on the cervical cord and proximal roots. When
there is disease involving specific
nerves, but not adjacent to the cord, or
when there is EMG evidence of muscle
disease but not nerve disease, the
scan can focus on those nerves or
muscles. For some patients, a cervical
cord scan is needed, for others a
brachial plexus scan is more useful,
and for some, a scan of the limb including long bones, specific joints or, for
example, triceps muscle, extensor
carpi radialis or flexor ulnaris muscles
may be a region of focus. When the
signs are subtle, electrodiagnostics are
worth the cost and the additional anesthetic procedure. Occasionally, electrodiagnostics show that although the animal is clinically lame on one leg, there
are widespread EMG or nerve conduction abnormalities, and then biopsy of
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muscle or nerve may be the next diagnostic step, and further imaging may
be unnecessary.
Another example: A 7 year old castrated male mixed breed dog has a history
of right forelimb lameness. There is no
radiographic abnormality, no joint pain
on orthopedic exam, and muscle atrophy is progressing over 4-6 weeks.
CBC, chemistry screen, urinalysis, and
radiographs of the right forelimb are
normal. General physical exam is unremarkable except for muscle atrophy
and pain on extension of the right forelimb, and pain on deep palpation in the
right axilla.
Neurologic exam shows mild proprioceptive deficits on the right forelimb
and the right hind limb, decreased
stretch and flexor withdrawal reflexes of
the right forelimb, poor skin sensation
on the dorsum of the right front foot,
right Horner’s syndrome, loss of cutaneous trunci on the right side, and
exaggerated stretch reflexes in the right
hind limb.
The changes affect both the forelimb
and the ipsilateral hind limb, suggesting that not only C6 – T3 nerve roots,
but the cervico-thoracic spinal cord
were affected. The most likely cause for
these signs is peripheral nerve sheath
tumor, lymphoma affecting cervico thoracic nerves, meninges or spinal
cord, or metastatic tumor affecting low
cervical or upper thoracic vertebral
bodies (sometimes a metastatic lesion
is not evident on survey radiographs
due to difficulty of positioning or problems with adjusting contrast when the
cervical spine is radiographed).
Electrodiagnostics and CSF tap could
certainly be useful, but the signs
strongly suggest that the disease is
near the cord and proximal C6 – T3
nerve roots on the right side, and MR
imaging alone may diagnose the
cause. If lymphoma is suspected
based on MR findings, a CSF tap may
be recommended immediately after the
scan.
The bottom line is, the more specific
the localization, the better the odds of
finding the true cause for subtle, chronic or progressive lameness. As always,
in neurologic diagnosis, it is location,
location, location! 䡲
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Cancers of the Joints
MONIKA JANKOWSKI, DVM, DACVIM (ONCOLOGY), SOUTHPAWS ONCOLOGY
Joint cancers are uncommon in dogs
and extremely rare in cats. The most
common primary joint tumors we see
are synovial cell sarcomas and histiocytic sarcomas.
Synovial cell sarcomas are malignant
tumors that tend to be locally invasive,
with a low to high metastatic potential
determined based upon histologic
grade. Synovial cell sarcomas arise from
the mesenchymal cells next to the synovial membranes which have the ability
to differentiate into epithelioid or fibroblastic cells. Synovial cell sarcomas are
usually found in large breed dogs. They
affect middle-aged dogs with lameness
being the most common complaint. At
the time of diagnosis, the metastatic rate
is approximately 30%. Radiographic
appearance of the affected limb can
include a periarticular soft tissue
swelling and bone invasion. This finding
can range from a poorly defined
periosteal reaction to multifocal punctate
osteolytic lesions, involving bones on
either but often both sides of the joints.
Once a synovial cell sarcoma is suspected, three-view chest radiographs
and careful evaluation of draining
lymph nodes are warranted to rule out
visible metastatic disease. The treatment of choice, if metastases are not
present, is limb amputation. Marginal
resection with joint reconstruction or
arthrodesis leads to high rates of local
recurrence and surgical failure. The
grade of synovial cell sarcomas (only
determined on a large section biopsy)
is highly prognostic. Survival times for
dogs treated with a limb amputation
alone is >48 months if the tumor is
grade I versus a survival time of
approximately 7 months with a grade III
tumor. Chemotherapy is advised for
dogs with grade III synovial cell sarcomas post-amputation and drugs chosen include doxorubicin or ifosfamide.
If metastatic disease is already present
(lungs or regional lymph nodes) at the
time of diagnosis, prognosis is poor
and the therapy tends to focus on palliative radiation, triple pain medication
therapy, and chemotherapy. We have
seen partial and complete remissions
with vast improvements in quality of life
for up to 6 months even in patients presenting with a painful, lytic joint, and
large lymph node metastases.
Histiocytic Sarcomas (HS) are malignant
tumors that originate from histiocytic
cells. There are two distinct types of histiocytic sarcoma based on their clinical
presentation and biologic behavior:
localized and disseminated. The HS
complex is a single disease complex
which can be thought of as localized
HS, disseminated HS, and malignant
histiocytosis. Localized HS arises from a
focal spot—usually on the extremities
and often near or within a joint.
This disease can be seen more commonly in Bernese mountain dogs, flatcoated retrievers, rottweilers, and both
golden and Labrador retrievers. It usually affects middle to older canines,
with no sex predilection. Most dogs will
present with a localized, rapidly growing soft tissue mass on a leg, often
adjacent to or involving a joint. Rarely,
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disease appears confined to a joint and
can have similar radiographic appearance to those seen in Synovial Cell
Sarcomas. This disease is highly
metastatic so three-view chest radiographs and an abdominal ultrasound
(as metastases can occur to the liver,
spleen, kidneys, or abdominal nodes),
as well as evaluation of draining lymph
nodes are necessary prior to determining a therapeutic plan. One study found
that 85% of dogs with what appeared
to be a focal joint histiocytic sarcoma
had visceral involvement at presentation. Diagnosing HS can involve both
cytology and histology of the localized
or disseminated lesions. Cytologic samples are generally highly cellular with
distinctly neoplastic mononuclear cells.
The treatment for HS is multi-modality
therapy using chemotherapy (CCNU or
doxorubicin), surgery, palliative radiation therapy, pamidronate, and pain
medications. The exact combination of
therapeutic modalities most appropriate
for the patient depends upon the stage
of disease at the time of diagnosis. In
those dogs with localized tumors only—
due to the high metastatic rate of HS—
a median survival time of only five
months is seen with amputation alone,
so chemotherapy is always advised
post-operatively in this type of cancer.
So, when you see a dog with a swollen
joint which radiographically appears
consistent with a joint tumor, how do
you tell which one it is? The only definitive diagnosis will require immunohistochemistry (IHC) on a large section
biopsy, however; cytology is often diagnostic or strongly suggestive. If you have
removed the tumor
(amputated the leg), the
IHC panel you request
should include vimentin
and cytokeratin for synovial cell sarcomas and
CD18 for histiocytic sarcomas. Dogs with synovial cell sarcoma which
expresses cytokeratin
have a high rate of
metastases, so
chemotherapy is advised
if that test result proves
positive. Remember to
request histopathologic
grading of any synovial
cell sarcoma as well. 䡲
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Polyarthritis in Small Animal Patients
DR. HEATHER HOCH, SOUTHPAWS INTERNAL MEDICINE
The key to determining the most appropriate therapy for a patient with painful
joints is to determine the underlying
condition causing the joint pain.
Immune-mediated polyarthritis (IMP) is
one of the more common etiologies of
polyarthritis and is often a diagnosis of
exclusion. Before beginning therapy for
suspected IMP, other diseases that
need to be eliminated include septic
polyarthritis, borreliosis, ehrlichiosis,
polyarthritis associated with inflammatory bowel disease, caliciviral polyarthritis
in cats, bacterial endocarditis-related
polyarthritis, rheumatoid arthritis,
degenerative joint disease, panosteitis,
hypertrophic osteodystrophy, and
underlying neoplasia. Animals with joint
pain, or conditions that affect the joints
can present with a wide variety of clinical signs including the classic “walking
on eggshells” stance, lethargy, inappetence/anorexia, and shifting leg lameness. Physical examination abnormalities may include joint pain, joint
swelling, warm joints, non-specific pain,
heart murmur, and fever. Diagnostics
recommended to differentiate the possible etiologies include a careful physical
and orthopedic exam, radiographs of
affected joint(s), CBC, chemistry,
urinalysis, thoracic/abdominal imaging,
and tick borne disease serology. In
cases in which a significant abnormality
is detected (an underlying cause for
the joint pain), the abnormal condition
detected should be treated and the
patient should be monitored for
improvement. If no significant abnormality is noted, arthrocentesis is
advised (samples obtained for cytology
and culture). Cytologic evaluation of
joint fluid is very helpful in diagnosing
IMP. Normal joint fluid is highly viscous
and is typically clear to pale yellow.
Cytologic evaluation of normal joint fluid
reveals non-degenerate macrophages
and lymphocytes, with less than 10% of
the cells being neutrophils. In patients
affected by IMP, marked suppurative
inflammation (many non-degenerate
neutrophils) is present. These findings
are not diagnostic for primary IMP as
similar cytology is seen in patients with
IMP secondary to IBD, bacterial endocarditis, and other forms of immunedisease. In contrast, animals with septic
arthritis have septic suppurative inflammation with degenerate neutrophils and
occasionally visible bacteria within
intra-articular inflammatory cells.
If IMP is suspected, and no underlying
disease such as IBD or bacterial
endocarditis is found, treatment with
immunosuppressives is indicated. I
typically begin therapy with prednisone
(1-2 mg/kg, PO, BID – for animals in the
hospital, I use dexamethasone - 0.150.25 mg/kg, IV, BID). I typically continue
at this dose for a minimum of 5-7 days
or until a clinical response is noted. In
patients that respond well to the prednisone therapy (initial response is typically noted in 24-48 hours), additional
immunosuppressive therapy is recommended (I typically use azathioprine 12 mg/kg, PO, SID for 5 days, then every
other day after that time). I typically
taper the immunosuppressive therapy
(tapering the prednisone therapy first)
over 4-6 months. One of the most common mistakes made is tapering the
immunosuppressive therapy too quickly. In many cases empiric therapy with
doxycycline is initiated. This antibiotic
helps to treat any potential underlying
rickettsial condition, as well as provide
anti-inflammatory therapy and antibiotic
coverage. In many cases it is necessary to provide additional pain therapy
with medications such as tramadol (2.55 mg/kg, PO, up to q 8 hrs.) and other
supportive therapy such as glucosamine/chondroitin sulfate. Many cases of
IMP initially respond to immunosuppressive therapy, but often relapse
when immunosuppressive therapy is
tapered or discontinued. 䡲
Typical Cytologic Findings in Arthrocenteses at SouthPaws
Normal
Tick-borne disease
Arthropathy
Degenerative
Arthropathy
Inflammatory
Arthropathy
Viscosity
High
Normal to
decreased
Normal to
decreased
Normal to
decreased
PMN
<5%
10-30%
<10%
70- 100%
Mononuclear
>95%
70-90%
>90%
0-30%
Comments
Only a small amount
should be present
(<0.5 mls in most
joints. Cell numbers
very low (<<50/slide)
Mononuclear cells
may be
morphologically
similar to small to
reactive lymphocytes,
plasma cells, and/or
macrophages. Cell
numbers high
(100-thousands per slide)
Cells are typically
mononuclear. Cell
numbers moderate
(10-200/slide)
Septic and nonseptic
etiologies can be
differentiated by
careful examination
of neutrophils in many
patients (degenerate vs.
non-degenerate). Bacteria
are rarely observed in
infected joints, and may be
difficult to culture. Cell
counts very high
(thousands per slide).
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Shoulder Imaging
ROBERT L. TOAL, DAM, MS, DACVR, SOUTHPAWS DIAGNOSTIC MAGING CENTER
RADIOGRAPHY
Traditional shoulder imaging involves 2 to 3 radiographic
views. These are an extended mediolateral view, an
extended PA view and a supinated view.
A common misconception regarding the extended mediolateral projection is that the goal is to superimpose the
shoulder joint over the trachea. The idea being that the
lucent trachea makes subtle lesions more conspicuous.
In my opinion this is not necessary. It is more trouble
than it is worth. Often when attempting to do this the
joint straddles the trachea creating a distracting background. A properly extended mediolateral shoulder joint
projection will position the joint surface over a relatively
thin layer of soft tissue. This provides a clear unobstructed view of the humeral articular surface contrasted
against a uniform background of soft tissue. Remember,
the involved joint is placed down on the table and the
upside shoulder and limb is pulled back. (See figure 1)
Figure 2- Diagram of shoulder joint view – PA
Occasionally, a special adducted view is needed to
enhance visualization of the caudomedial humeral surface. This is called the supinated view. The supinated
view is done with the patient in the standard mediolateral
position. The then place a wedge under the elbow to roll
the caudomedial surface of the humeral head into the
beam tangent. The supinated view more consistently
demonstrates lesions of OC or OCD in medial area of
the humeral head.
Radiographic imaging of the shoulder is the mainstay for
evaluation in young growing dogs for Osteochondrosis
as well as providing valuable information in lame dogs
due to degenerative joint disease, soft tissue mineralization, trauma, and neoplasia.
Often severe lameness may be present that has a normal appearing shoulder radiograph. For example, this
can happen with nerve root tumor, soft tissue tendon disease as in biceps or supraspinatus tendon injuries or
with soft tissue tumors especially some histolytic sarcomas. Additional imaging is required to diagnose these.
Figure 1 – Diagram of mediolateral shoulder view
An extended PA view of the shoulder is best done with
the patient in dorsal recumbency in a soft “V” trough.
The legs are extended forward as in a VD chest film.
The next step is the key. Try rotating the patient about
30 degrees by tilting the sternum to the side away from
the joint of interest. This moves the involved shoulder
joint up slightly, bringing the shoulder joint proximal
humorous and scapula in beam tangent allowing for a
more thorough view of all of these key structures. (See
figure 2)
MAGNETIC RESONANCE IMAGING
AND COMPUTED TOMOGRAPHY
Magnetic Resonance Imaging (MRI) is excellent at diagnosing boney as well as soft tissue lesions. It has superior contrast resolution vs CT. With CT, diseased tissues
show only a maximum of 5% differences in tissue conContinued on page 7
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Shoulder Imaging...Continued from page 6
trast vs normal. MRI will show up to a 40% difference in
contrast between normal and diseased tissues. This
means that MRI will make all diseased tissues easier to
identify (brighter whiter) vs. CT. On the other hand, CT
has better spatial resolution (more fine detail is seen) vs.
MRI. When lesions cause structural alterations, CT is
excellent at showing these changes. This factor is important making CT a useful modality in shoulder imaging
diagnostics for many lessons.
those inside the spinal canal. MRI is also excellent for
diagnosing tendon lesions which includes abnormality of
their insertions (seen as high signal edema in bone),
tendon and muscle damage (seen as high signal edema
and structural discontinuity), and it is very good at diagnosing bony lesions, particularly those involving the
medullary cavity (edema, infection, tumor). This is
because the rich medullary cavity has abundant soft
tissue elements that are altered in various disease
conditions.
A common misconception is that MRI is better for soft
tissue imaging and CT is better for bone. Not true. Very
subtle lesions of bone edema and early bone tumor are
easily seen with MRI. A case example is a patient sent
for an MR for a suspected disc hernia but the scan
show high signal in the proximal humeral medullary
cavity. Neoplasia (sarcoma) was found on biopsy. This
subtle change was not seen on radiographs and would
have been difficult to see on CT. (Figure 3)
CT is excellent at showing structural changes in bone
such as might be seen in more advanced bone tumors,
congenital lesions and trauma. Also, the three dimensional high detail reconstructed CT images are always
helpful in planning surgery. CT is the modality of choice
for doing radiotherapy planning. A case example of a
chronic lameness in a young dog with equivocal pain in
the shoulder or elbow joint is shown. A CT of the entire
leg was done. Incomplete ossification of the condyles
was seen. The shoulder was normal. (Figure 4)
Figure 3
MR of a humerous with proximal
bone tumor seen as high signal
Figure 4
CT of incomplete
ossification of the distal
condyles. The shoulder
was normal
So the next time you have that stubborn shoulder
lameness case, be sure to call us at SouthPaws to get a
handle on what imaging modality, if any, should be done
next. 䡲
In my experience MRI is superior to CT for diagnosing
nerve root tumors (seen as high signal thick nerve roots).
This includes nerve root tumors that are peripheral and
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MARK YOUR
CALENDARS now
for our next CE
Extravaganza on
Sunday October 4th.
Your techs, assistants (and
you) won’t want to miss it!
Acupuncture for Shoulder Problems
JORDAN KOCEN, DVM, MS, CERTIFIED VETERINARY ACUPUNCTURIST
Acupuncture therapy for shoulder problems
can be quite successful. Many dogs that
present with foreleg lameness with pain on
manipulation of the shoulder joint are not
specifically scapulo-humeral problems, but
do involve attachment of the brachial
appendage onto the body. Most involve soft
tissue problems: stressed muscle, ligament
and tendon. Since dogs are weight bearing
on the front legs the attachments of the
forelimb to the body can be really stressed;
some from primary damage and a lot from
compensating for weight shifting from the
hind end. We often detect sensitivity on
gentle manipulation of the paravertebral
muscles in the region of T3-T5. Sometimes
extra tension in the C7-T1 area will cause
enough nerve root compression that the
dogs exhibit weakness and pain sensation
in the forelimb.
Some cases do not have a specific diagnosis other than the symptom presentation of
pain in the shoulder region or undefined
lameness of the foreleg. Acupuncture can
be initiated in these cases since we are not
treating a specific local problem, but rather
improving the function of all of the tissues
that make up the functional unit of the
shoulder region.
We often include acupuncture points that
will help the hind end in these forelimb
lameness patients, too. If the problem is primary to the front end, the treatment of the
hind end provides support when the patient
wants to shift its weight caudally.
Since there is nothing on the needles, concurrent therapy with pharmaceuticals will
not create a negative reaction. Many cases
are started while NSAIDs or steroids are in
use. These medications can often be discontinued or significantly reduced once
acupuncture therapy is started. 䡲
I-395
Acupuncture helps these cases because of
its affects on muscle spasm and the release
of endogenous steroids and opioids. Acute
cases will often respond with one to two
treatments. Chronic cases will usually
require four treatments for improvements to
be noted. Often continued treatment at
lengthening intervals will help decrease the
likelihood of the problem returning. It seems
that the treatment helps the body retrain the
muscles in the area to manage weight
bearing in such a way that the return of
inflammation and spasms is less likely.
y
Beltwa
Our convenient new location:
Just outside the beltway on
Route 50 near Fairfax Hospital
SouthPaws Veterinary Specialists & Emergency Center
8500 Arlington Blvd.
Fairfax, Virginia 22031
Tel: 703.752.9100
Fax: 703.752.9200
DIRECTIONS TO FACILITY
From the north and south directions on the Beltway take exit
50A US 50 West. Go to the second light, Javier Rd., and make a
right. Make an immediate left
onto Arlington Blvd. Frontage Rd.,
in front of the BB&T bank. Look
for the paw print on the building.
Our new location is easy to find,
offers ample parking, and provides the same great service you
have come to expect from
SouthPaws.
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