Joint - Inflammatory Conditions Flashcards
What are the different types of non-inflammatory joint disease?
- Degenerative joint disease/OA
- Instability
- Trauma
- Developmental diseas
- Coagulopathic joint disease
- Haemorrhage into a joint associate with coagulopathy such as haemophilia
What are some infectious inflammatory joint diseases?
What do we mean by inflammatory joint disease?
- Infectious inflammatory joint disease
- Be aware of
- important species differences
- the significance of signalmentand history
- the need for rapid diagnosis and effective treatment
- Septic (bacterial) arthritis (important)
- Non bacterial causes
- Rickettsia (tick-borne disease egBorrelia, RMSF)
- rarely
- mycoplasma, chlamydia, fungal, viral and protozoal infections seen in dogs and cats
- chlamydia, viral and mycoplasma in sheep
- Be aware of
What are some sterile inflammatory joint diseases?
What do we mean by inflammatory joint disease?
- Sterile inflammatory joint disease
- Be aware of •important species differences
- the significance of signalmentand history
- Immune mediated polyarthritis (IMPA)
- Erosive polyarthritis (rare)
- Idiopathic erosive polyarthritis
- Rheumatoid arthritis
- Semi-erosive polyarthritis of greyhounds
- Periosteal proliferative polyarthritis in cats (rare)
- mainly proliferative but also can have an erosive component
- Erosive polyarthritis (rare)
Is erosive or non-erosive immune mediated polyarthritis more common?
Non-erosive IMPA more common
What are the different types of non erosive polyarthritis (IMPA)?
- Immune mediated polyarthritis (IMPA)
- Non erosive polyarthritis (more common than erosive)
- Type I: idiopathic IMPA (most common)
- Type II: associated with infection remote from the joint (25% of cases)
- Type III: associated with GI disease (15% of cases)
- Type IV: associated with neoplastic disease iea paraneoplastic syndrome (rare)
- SLE or SLE related multi systemic immune mediated disease (rare)
- Jtdisease AND other disease
- glomerular disease?
- skin lesions? (mucocutaneousjct)
- IMHA +/-thrombocytopenia?
- Non erosive polyarthritis (more common than erosive)
What is the most common type of non erosive polyarthritis (IMPA)?
Type I - idiopathic IMPA
What is type II non erosive polyarthritis associated with?
Associated with infection remote from the joint
What is type III non erosive polyarthritis associated with?
Assocaited with GI disease
What is type VI non erosive polyarthritis associated with?
Associated with neoplastic diases i.e. a paraneoplastic syndrome (rare)
What are some usual syndromes that can cause non-erosive polyarthritis (IMPA)?
- Unusual syndromes:
- Polyarthritis/meningitis syndrome
- Polyarthritis/polymyositis syndrome
- Breed associated non erosive IMPA
- Wide range of breeds egweimeraner, boxer, akita, BMD, GSHP, spaniels and beagles
- Familial Shar-Pei fever
- Drug induced IMPA (rare, idiosyncratic reaction)
- Immune complex deposition as a result of drug-antibody interaction
- Reported with sulphonamides espin Doberman
- Post live calicivirus vaccine in cats
What is neoplastic arthritis?
Neoplastic arthritis
- Predominantly synovial cell sarcomas
- (other tumours, such as fibrosarcoma, haemangiosarcoma, osteosarcoma less common)
- Seen in dogs
- very rare in cats and large animals
- Mainly occur in large joints of limbs (stifle)
- Typically causes lameness, joint effusion, soft tissue swelling and lytic areas / bone destruction (both sides of a joint) on radiography Useful resource for information about a wide range of tumours: VSSO
If there are changes to both side of the joint, what is it most likely to be?
Most likely a primary tumour of the joint itself
What is crystal induced arthritis?
- Crystal induced arthritis
- true gout occurs in species that do not have enzyme uricase= humans, birds and reptiles
- white, peri-articular deposits inflammatory reaction
- dogs -RARE -peri-articular and synovial deposits of calcium pyrophosphate (pseudogout), or Ca phosphate single or multi-joints synovitis and lameness
Gout is an important differential to consider in a lethargic iguana
Why is classification of inflammatory joint disease complex but important?
- Identifying an underlying cause can:
- guide specific clinical treatment
- Help to determind prognosis
- Specific breed associations alert us to the likelihood of underlying genetic predispositions in immune mediated disease
Septic arthritis and IMPA require very different treatment
What causes septic arthritis in a single joint in an adult animal?
- Caused by trauma (penetrating wounds, bites in small animals)
- Can occur post surgery or following intra- articular injection (steroids, HA and PsGAGS all predispose to infection)
- Idiopathic cases have also been reported (no cause identified)
- Dogs: increased risk in joints with underlying OA
- **sudden deterioration in a dog with chronic arthritis**
- Dogs: increased risk in joints with underlying OA
Steroid injections in humans is common so they often keen to have it done in their pets - but can be a risk factor for septic arthritis. Also as steroids are immunosuppressive.
Often in SA - can be idiopathic, don’t know where bugs get in, but more common in a dog with pre-existing OA
What causes septic arthritis in multiple joints in an adult animal?
- Haematogenous spread in debilitated / immuno-suppressed animals
- Non-bacterial causes:
- Rickettsia (tick-borne disease)
- +/-immune mediated component
- Rarely –myoplasma, chlamydia and fungal, viral and protozoal infections seen in dogs and cats, chlamydia, viral and mycoplasma in sheep
- Rickettsia (tick-borne disease)
Calicivirus in cats: may see inflammatory joint disease together with pyrexia and other flu symptoms. Worth bearing in mind but other clinical signs are usually more obvious. May not be a true septic arthritis, may be an immune reactive arthritis 2ry to viral antigen.
What do you see with calcivirus in cat and how can this cause joint problems?
Calicivirus in cats: may see inflammatory joint disease together with pyrexia and other flu symptoms. Worth bearing in mind but other clinical signs are usually more obvious. May not be a true septic arthritis, may be an immune reactive arthritis 2ry to viral antigen.
What can cause septic arthritis in multiple joints in a large animal neonate?
Joint ill - septic arthritis
What is the pathophysiology of joint ill in LA neonate (septic arthritis)?
Failure of passive transfer –> umbilical infection –> haematogenous spread of bacteria –> joint sepsis +/- osteomyelitis
How can lambs differ with regards to joint ill and where it spreads from?
In lambs, think about site of entry being tail docking or castration site.
But largely umbilicus, as with a lot of LA neonates
IMPA is a sterile inflammatory joint disease.
What causes IMPA?
What causes IMPA?
- Type III hypersensitivity reaction
- Immune complex deposition in synovial basement membrane
- Complement cascade activation
- Recruitment of inflammatory cells
- Neutrophils & macrophages
- End result = release of nitric oxide, free radicals and proteases –> tissue damage
If the inciting antigen is found and/or the underlying cause can be treated this is important and potentially avoids use of immune suppressive drugs and associated side effects.
What is inflammatory joint disease diagnosis based on with regards to species and signalment?
Diagnosis is based on…
- Species and signalment –
- IMPA unlikely in a horse or large animal
- What age is your patient?
- IMPA more common in
- larger breed dogs <6 yrs of age » BUT…also seen in smaller breeds and mixed breeds
- dogs than cats
- IMPA more common in
What is inflammatory joint disease diagnosis based on with regards to clinical history?
Clinical history
- Acute or chronic?
- Any history of trauma or wounds or recent surgery?
- Lameness
- In one leg or > 1 leg?
- In SAs septic joint disease usually affects 1 joint only
- Consistent or shifting from 1 leg to another?
- Waxing and waning signs are sometimes seen with immune mediated disease
- In one leg or > 1 leg?
- Any other problems or “just” painful joint(s)?
- Poor appetite and/or weight loss?
- GI signs?
- Skin disease?
What is inflammatory joint disease diagnosis based on with regards to physical exam?
Physical examination:
- Fever/pyrexia?
- IMPA dogs can have an intermittent fever
- Multiple or single joints involved?
- IMPA dogs can appear stiff rather than lame
- Palpation of joints to assess
- heat
- swelling
- range of movement
- pain
- site of injury?
- Any neck or muscle pain?
- Concurrent meningitis or myositis?
- Any enlarged LNS?
What is inflammatory joint disease diagnosis based on with regards to arthrocentesis for joint fluid analysis?
Arthrocentesis for joint fluid analysis
- Easy and very cost effective
- 25G needle and a 3ml syringe
- Can be done under sedation (or GA)
- Sterile technique is crucial
- Check anatomical landmarks before you start
- Don’t aspirate too fiercely or à haemorrhage
- Assess fluid for viscosity as you make a smear
- Sample in blood culture medium may be more likely to give a positive culture in septic arthritis cases
Is IMPA more common in dogs or cats?
More common in dogs than cats
Is IMPA more common in larger or smaller breed dogs?
More common in larger breed dogs <6 years of age
But also seen in smaller breeds and mixed breeds
When doing joint fluid analysis, what should you request to do with the sample?
- Total and differential white cell counts
- Cell morphology
- Culture and sensitivity
- Blood culture medium
- +/- blood and urine culture
When would you need radiography to aid with the diagnosis of inflammatory joint conditions?
Diagnosis: what else do we need? Radiography?
- Maybe only needed if
- joint palpation reveals:
- crepitus
- instability
- poor range of movement
- deformity
- there is a poor response to treatment
- joint palpation reveals:
With non-erosive IMPA, what are we likely to see on radiography?
Joint effusion is likely to be the only finding
What are you likely to see on radiography with erosive IMPA?
Multiple joints, often symmetrical, subchondral defects, collapsed joint spaces, proliferation and calcification of periarticular soft tissues
Grossly abnormal in established disease
Normal on left pic and erosive IMPA on right
When might contrast studies be useful for the diagnosis of septic arthritis?
Contrast studies might be helpful in horses especailly
Look for communication between tract/sinuses and a joint. You might be able to identify a foregin body
What is shown here and what might it be useful for?
Contrast studies might be helpful in horses especailly
Look for communication between tract/sinuses and a joint. You might be able to identify a foregin body
Which types of IMPA are you likely to use radiography to aid with diagnosis and why?
Use radiography is you suspect type II, III or IV IMPA or multi systeic immune mediated disease
As additional imaging might be required such as thoracic radiographs, abdominal ultrasound or echcardiography
As a mets check or looking for the underlying disease that is causes the lameness and joint problems
What are some additional lab tests you can use for diagnosis of inflammatory joint conditions?
Additional lab tests?
- Haematology
- Inflammatory leucogram?
- Anaemia of chronic disease or IMHA?
- Biochemistry
- Changes consistent with systemic disease
- Urinalysis
- Proteinuria or other evidence of glomerulonephropathy
- Serology?
- ANA and RF (rheumatoid factor) -very non specific in dogs
- false +veand false –vesoccur
- Histopathology: tissue biopsies for unusual syndromes?
What are some potential treatments for septic arthritis?
- Must be fast and aggressive for success
- Systemic and intra-articular antibiotics
- Joint lavage and drainage
- Surgery/arthroscopy
What should the systemic antibiotics for the treatment of septic arthritis be like?
Systemic antibiotics
- Broad spectrum (wound contaminants often skin commensals, plus environmental bacteria)
- Remember takes time to get culture & sensitivity therefore often have to start before results
- Commonly used:
- Amoxicillin / clavulanatein small animals
- Pencillin+ aminoglycoside in large animals
- Need high plasma levels and long duration tx:
- start with IV or IM administration
- switch to oral after 5-7 days
- total duration usually 2-4 weeks at least
What are some commonly used systemic antibiotics for the treatment of septic arthritis?
Amoxicillin/clavulanate in SA
Penicillin + aminoglycosides in LA
What should the duration of treatment with systemic antibiotics for the treatment of septic arthritis be like?
- Need high plasma levels and long treatment duration
- Start with IV or IM admin
- Switch to oral after 5-7 days
- Total duration usually 2-4 weeks at least
What should the local antibiotics you use for the treatment of septic arthritis be like?
Local antibiotics
- Intra-synovial administration commonly used in large animals
- Achieves high doses with low cost and toxicity
- Gentamicin, amikacin and ceftiofurall used in horses
- Risks of nephrotoxicity higher in dogs •
- Slow release products (antibiotic impregnated beads or collagen sponges) can be useful in chronic / difficult cases
- Think about whether you need systemicsas well (spread through soft tissues or involvement of other tissues, such as bone)
What are some surgical options for the treatment of septic arthritis and when are these justified?
Surgical options:
- Lavage and drainage
- Arthroscopy - allows direct visualisation of the joint, removal of fibrin, foreign material or articular fractures
- Arthrotomy
When are these justified?
- Horses –antibiotics alone rarely resolve the infection, recommend lavage as a minimum
- Lavage indicated in farm animal cases and more severe small animal cases, where costs allow….
If you decide to treat septic arthritis surgically, what is the post op care like?
Post-op care
- NSAIDs for patient comfort and reduction of inflammation
- Rest / controlled exercise / physiotherapy
- Depending on severity and duration, cartilage will be damaged so early return to exercise and loading can lead to OA
- Avoid intra-articular medication espin early stages as predisposes to infection
What is the treatment of IMPA if the underlying cause is known or found?
- Treat/remove the underlying cause or antigenic trigger
- i.e. be sure of your diagnosis
- give analgesics while managing the 1ry disease
- nutritional support if needed?
What is the treatment of IMPA when no underlying disease or cause has been found?
When no underlying disease or cause is found: immune suppressive treatment
- Single agent eg prednisolone
- Be aware of and discuss side effects with owners
- Gradually reducing dose
- Combination therapy eg prednisolone +/- ciclosporin or azathioprine for refractory cases or if steroid side effects are worrying
- Azathioprine is toxic in cats and should not be used
- “Newer” single agent therapy:
- Mycophenolate
- Luflenomide
What is the monitoring for IMPA?
Monitoring:
- Clinical signs?
- Physical exam findings?
- Follow up arthrocentesis?
- Serum C reactive protein
- A good surrogate marker for synovial inflammation
- Good correlation with pain scores and joint cellularity
- Objective and non invasive way to monitor problem cases?
What is the prognosis for IMPA?
The prognosis can be very good but as with all immune mediated diseases there are no guarantees and relapses are not uncommon. Start treatment and keep reviewing progress.
What is the treatment for EROSIVE IMPA?
Erosive IMPA: treatment
- Prognosis is more worrying
- Surgical salvage procedures might be required/indicated
- Arthrodesis
- Excision arthroplasty
- Total joint replacement
- Euthanasia is a reasonable alternative
Think about:
- the welfare issues associated with intractable joint pain….
- the difference between stiffness and pain
What are some differential diagnoses of inflammatory joint disease?
- Other causes of pyrexia-IMPA is a major differential for PUO even when no obvious lameness is found. These dogs can just be miserable and don’t always give much away!
- Non inflammatory arthritis (OA/DJD)
- Other orthopaedic conditions
- Articular fractures?
You will be able to come up with other differentials from other MSK lectures and from other modules when you think about pyrexic dogs and cats.
With inflammatory joint disease, what does the diagnostic plan rely on?
- A good and thorough assessment of the clinical presentation
- An ability to perform effective arthrocentesis
- Review of all the clinical information if a case is not progressing as you think it should
How many joints are affected in IMPA compared to septic arthritis?
IMPA - multiple
Septic arthritis - typically only 1 in SAs
Which joints are often affected in IMPA compared with septic arthritis?
IMPA - smaller, distal joints e.g. hocks, carpi, stifle
Septic arthritis - more proximal larger joints e.g. elbow
How common is local soft tissue swelling with IMPA compared with septic arthritis?
IMPA - uncommon
Septic Arthritis - common
What do you often seen on synovial fluid analysis with IMPA and septic arthritis?
IMPA - ~300 cells x109/L <95% neutrophils usually non degenerate
Septic arthritis - cell count variable but usually very high. Most cells are DEGENERATE neutrophils
Synovial fluid analysis shows NON-DEGENERATE neutrophils:
IMPA or septic arthritis?
IMPA - non-degenerated
Septic arthritis - degenerate
Do you see bacteria with IMPA or septic arthritis?
IMPA - none on cytology, culture negative
Septic arthritis - might see on cytology, culture often negative. Sometimes they just don’t make themselves available, if they are not there - doesn’t rule septic arthritis out! Joints are full of bacteria, its just that the bacteria are in a very sensitive spot.
If you have a pyrexia of unknown origin that seems to have a slight response to antibiotics but keeps reoccuring, what should you consider?
Consider IMPA
Dogs come in with temperature, not quite right, may not find much on physical exam
Waxing and waning disease irrespective of what you give it, as you arent giving right treatment for immune mediate disease! Be aware of temptation - if something keeps coming back with constant temperatures, think about this
Think about IMPA in PUO/FUO cases especially if there seems to have been a response to antibiotics but actually the disease is just waxing and waning
What are some top tips for spotting IMPA?
- Think about IMPA in PUO/FUO cases especially if there seems to have been a response to antibiotics but actually the disease is just waxing and waning
- Fully flex the carpi and squeeze if necessary to see if there is a pain response
- Check for any subtle enlargement of the LNs (prescaps, popliteals, sub mandibular)
- Aspirate multiple joints-carpi, stifles and hocks. Changes in > 1 joint and no bacteria on cytology or culture suggest IMPA more likely
- More likely to find changes on haematology and biochemistry cfnon inflammatory joint disease
- Leucocytosis
- Hypergobulinaemia
- Mild hypoalbuminaemia
- Urinalysis might show proteinuria
- If all blood and urine tests are normal this does not rule out IMPA-joint fluid is more important and more useful.
What are some similarities and differences between erosive and non erosive IMPA?
Similarities:
- Clinical signs
- Synovial fluid analysis
- Treatment
Differences
- Radiographic signs
- Response to treatment (erosive doesnt respond well to treatment)
- Prognosis
What is the prognosis of septic arthritis in small animals?
Small animals
- Outcomes (following systemic antibiotic administration only)
- 56% full clinical recovery –
- 32% persistent mild lameness
- 12% poor response (consider lavage!)
- Factors affecting outcome:
- Duration, severity, multiple joints affected, concurrent problems (e.g. bacterial endocarditis)
What is the prognosis of septic arthritis in equine?
Equine - depends on site and cause
- Adults >80% resolution of infection and return to athletic function
- Factors affecting outcome: duration and severity of injury, site of injury, fractures and osteomyelitis
- Small tarsal joints, calcanealbursaland navicularbursa have reduced prognosis but specific surgical techniques improve this
- Foals approx 50% for resolution of infection
- But only 30% achieved racing performance
- Factors affecting outcome: septicaemia, osteomyelitis and hypogammaglobulinemia
