Clinical Manifestations of and Diagnostic Tests for Joint Diseases

Lecture 2

Animal with joint disease commonly present with a history of ____ or ____.

lameness

gait abnormality

Lameness involving one joint/limb is typically?

traumatic or developmental

Lameness involving multiple joints/limbs is typically?

degenerative or inflammatory

Non-inflammatory joint disease has what predominant cell type on cytology?

monocytes

Inflammatory joint disease has what predominant cell type on cytology?

neutrophils

List categories of non-inflammatory joint diseases.

developmental (UAP, FCP, OC/OCD)

degenerative (hip dysplasia)

neoplastic

traumatic processes

List categories of inflammatory joint diseases.

infectious (Borrelia burgdorferi, Staphylococcus, Ehrlichia spp)

non-infectious (immune mediated) —> erosive (rheumatoid arthritis), non-erosive (SLE)

Is this inflammatory or non-inflammatory joint disease:

• very painful joints; multiple joints affected

• shifting leg lameness

• systemic disease —> fever, lethargy, inappetence, exercise intolerance

infammatory

Is this inflammatory or non-inflammatory joint disease:

• low grade chronic discomfort

• fluctuating/intermittent lameness

• reluctance to exercise

• no systemic signs of illness

• multiple joints affected

• “warms out” of lameness

non-inflammatory

What should you be assessing during physical exam for suspected joint disease?

goal is to localize region of pain or inflammation

assess animal’s posture and gait

manipulate and palpate the spine and the muscles, bones, and joints of each limb

give equal consideration to a systemic exam (auscultation and abdominal palpation)

List differentials for pain upon palpation of bones.

trauma

panosteitis

hypertrophic osteodystrophy

osteomyelitis

bone neoplasia

List differentials for pain upon palpation of muscles.

myositis

strain/sprain injuries

List differentials for pain upon palpation of the neck.

spinal cord or vertebral abnormalities such as IVDD, intracranial disease, meningitis, polyarthritis

List differentials for pain upon palpation of the spine.

spinal cord or vertebral abnormalities such as IVDD, discospondylitis, intervertebral facet joint inflammation

A decreased joint ROM, crepitation, and joint instability on physical exam suggests what?

articular damage and wear

osteophytes

peri-articular changes

tendon/ligament damage

What is the largest and easiest of joint to tap on a dog?

radiocarpal joint

Where is effusion most obvious on the carpus?

cranial and medial aspects of joint

Where is effusion most obvious on the elbow?

lateral aspect between lateral epicondyle and olecranon

How can you detect effusion in the stifle?

patellar ligament becomes indistinct and medial joint pouch protrudes

Where is effusion most obvious on the tarsus?

craniomedial, craniolateral, caudolateral, and caudomedial aspects, adjacent to the collateral ligaments

What is the minimum views we want when taking joint radiographs?

2 orthogonal views 90 degrees to each other

What imaging modalities can be used for joints?

radiography

CT

MRI

Ultrasound

Which imaging modality is used for initial diagnositc evaluation when only one joint is clinically affected, or joint palpation reveals crepitation, instability, or a restricted ROM?

radiography

What is the most common polyarthropathy in dogs?

immune mediated polyarthropathy (IMPA)

What is labeled by 1?

humeral diaphysis

What is labeled by 2?

humeral condyle

What is labeled by 3?

anconeal process with superimposed epicondyle of the humerus

What is labeled by 4?

tuber olecranon

What is labeled by 5?

medial choronoid process of ulna with superimposed radial head

What is labeled by 6?

lateral choronoid process of the ulna

What is labeled by 7?

cranial aspect of the radial head

What is labeled by 8?

proximal diaphysis of radius

What is labeled by 9?

proximal diaphysis of ulna

By what age should the growth plate be closed for the anconeal process?

6 months

If polyarthritis is suspected, synovial fluid should be analyzed from how many joints?

three to four, including at least one carpus, one hock, and one stifle

Describe normal synovial fluid.

thick, viscous fluid secreted by synovium —> should form a strand of at least 1 inch when pulled apart

clear to slightly yellow in color

high content of HA and additional molecules such as lubricin

What is the primary function of synovial fluid?

lubricate articular surfaces and facilitate movement within the joint

What cell profile should be seen with normal synovial fluid on a 40x field for cytology?

no more than 3 WBCs per high dry power field

mixture of large and small mononuclear cells

<10% neutrophils

You are presented with a synovial fluid cytology with the following characteristics:

• 1000-6000 WBC/uL

• 0-12% PMN

What type of joint disorder do you suspect?

Degenerative

You are presented with a synovial fluid cytology with the following characteristics:

• 40,000-280,000 WBC/uL

• 90-99% PMN

What type of joint disorder do you suspect?

Septic

You are presented with a synovial fluid cytology with the following characteristics:

• 4000-370000 WBC/uL

• 15-95% PMN

What type of joint disorder do you suspect?

Nonerosive immune mediated

This is synovial fluid from a canine stifle.

• What are these cells?

• Is this cytology consistent with normal, inflammatory or noninflammatory joint disease?

• Name a common joint disease that is consistent with this cytology?

Mononuclear/macophage-type cells

Non-inflammatory

Ruptured CCL

This is synovial fluid was taken from the carpus of a dog with a fever.

• What are these cells?

• Is this cytology consistent with normal, inflammatory or noninflammatory joint disease?

• What are two differential diagnoses for this patient based on this cytology?

Neutrophils

Inflammatory

Tick borne / infectious disease OR immune mediated such as rheumatoid arthritis

What other tests should be done for joint cases in order to rule out systemic disease?

radiographs of abdomen and thorax

bloodwork —> tick borne disease panels, immune panels (ANA, LE, RF)

cultures of blood, urine, bone