Inflammatory joint disease Flashcards
Inflammatory joint disease including various pathologies, diagnosis, treatment, synovial fluid and cytology. Useful resource: https://eclinpath.com/cytology/synovial-fluid/
Characteristics of a normal synovial fluid sample
- Straw-yellow in colour
- Clear
- Viscous
Which synovial fluid cytological parameters are useful to evaluate in cases of suspected joint infection/inflammation?
- Total leukocytes → will be increased in joint disease/inflammation
- Neutrophils
- Total protein (obtained used refractometer)
Synovitis
Inflammation of the synovial membrane/joint
Tenosynovitis
Inflammation of the tendon sheath
Bursitis
Inflammation of the bursa
Possible (broad) causes of inflammatory joint disease
- Developmental e.g. OCD
- Degenerative e.g. OA
- Iatrogenic e.g. surgery/injection introduced infection
If inflammation occurs as a result of a joint injection, how long after said procedure would you expect to see the inflammation?
24-48hrs
What first line options are there for use as part of a lameness workup/joint investigation?
- Lameness exam
- Palpation, trot up, flexion tests
- Perineural anaesthesia
- Intrasynovial anaesthesia
- Synovial fluid sample
- Radiography
- Occasionally ultrasound
When might you use scintigraphy in cases with suspected joint disease?
- Often used in cases with poor performance history
- Often used in cases hard to diagnose initially
- Can identify the source of bone remodelling, then take radiographs to view this specifically
What does MRI allow you to visualise in the joint that other imaging modalities do not permit?
Cartilage
What immediate course of action is suitable for:
A horse with acute joint inflammation due to a fracture with an intra-articular component?
Arthroscopy and removal of the fragment
Surgical stabilisation of the remainder of the fracture if necessary
What immediate course of action would you suggest for the following:
A horse has sustained a penetrating wound to the metacarpo-phalangeal joint. The wound penetrates the joint synovium and is greatly contaminated.
- Arthroscopy
- Lavage to remove contamination
What is the gold standard treatment for joint sepsis?
Joint lavage
Arthroscopy to remove contamination
What main methods of delivery can we used for therapeutics for joint disease?
- Systemic - potentially easier to deliver but can come with profound side effects
- Intra-articular route
- Common in equine, not licensed in small animals but drugs used under cascade
- Can circumvent some undesirable effects of systemic medication
What is this cell? It was found in synovial fluid in an animal with non-inflammatory joint disease (i.e. pathology was due to trauma or DJD)
Osteoclast
This is a cytological smear from equine synovial fluid. What can you see that might be relevant?
Presence of bacteria indicating infection
Sepsis and joint infection used interchangeably in equine
This is a cytological slide from a synovial fluid sample from a cat with polyarthritis. Which cells are present?
Ragocytes (large nuclei and pink cytoplasm)
LE cells
What is an LE cell?
LE cell: a neutrophil or macrophage that has phagocytized the denatured nuclear material of another cell.
They are seen in lupus erythematosis (LE)
What are ragocytes? When and where are they seen?
- Neutrophils containing purple to dark blue particulate material in their cytoplasm/cytoplasmic inclusions.
- These inclusions might be nuclear fragments or nuclear antigen-antibody complexes
- They are found in inflammatory synovial fluid
- They are associated with arthritis
What cells are visible in this synovial fluid sample from a joint with DJD?
Mononuclear cells (non-reactive macrophages, M, and some lymphocytes, L)
What cells are present in this synovial fluid sample from a dog with villonodular synovitis? Are they activated and how can you tell?
- Predominant cell type: macrophages
- they have distended, “foamy” looking lightly vacuolated cytoplasm so are activated
- There are also a small number of lymphocytes
