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www.southpaws.com 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 1 www.southpaws.com 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 2 www.southpaws.com 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 3 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 www.southpaws.com 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, 4 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 www.southpaws.com 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). 5 www.southpaws.com 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 6 www.southpaws.com 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 7 www.southpaws.com 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. 8