PRACTICAL: MSK pathology, imaging and diagnostics Flashcards
Appearance - normal joint fluid
- small volume
- clear straw coloured
- viscous b/w fingers d/t HA
- fluid shouldn’t clot but will form gel if left to settle
Why do you tend to see neutrophilic inflammation in the horse?
usually with infxn following a penetrating wound. If cell #s are very low, then acute local trauma may also be considered.
Tx- septic arthritis (EQ)
- BS AB 4-6 wks
- examine area for wound
- consider contrast rads. to determine if communication b/w wound and joint (remember joint sampling)
- infected joitns should be sx lavaged ASAP to facilitate good recovery and return to work
Can infectious diseases show PA?
Yes - test for tick bourne diseases (Ehrlichia, Borrelia)
If you suspect RA, what test do you run?
ANA titres
T/F: sometimes with degenerative arthropathies, no cytologic changes are seen
True
What are commonest sites for OSA?
“away from the elbow and close to the knee”
- proximal humerus and distal radius
- distal femur and proximal tibia
How is OSA an unusual sarcoma?
it doesn’t spread in bone from its original location, instead it spreads to the thorax (can and readily do metastasise here)
Microscopic appearance - OSA
- extreme cellularity
- pink osteoid b/w cells
- mitotic figures
Action for CCLR
- weight management
- exercise
- I/a steroids
- NSAIDs
- neutraceuticals
- sx stabilisation: intra-articular, extra-capsular or osteotomy techniques
Outline relationship b/w exercise and OCD
not thought that exercise causes OCD per se but once OCD starts, exercise does exacerbate it
Actions - OCD
- radiograph contralateral area
- Tx - arthroscopy and debridement of subchondral bone bed and remove cartilage flap (if present)
- conservative (exercise restriction and analgesics) although less successful than sx
Define AE complex
Articular- epiphyseal complex
T/F: cartilage thickness varies normally across a joint d/t different pressure gradients
True
List radiographic signs of laminitis
- gas showing separation of laminae
- P3 rotation
- foundering (P3 sinking)
- hoof wall separation
What may fill a space b/w detached epidermal laminae of inner hoof wall and dorsal surface of P3?
- proliferated epithelium
- necrotic tissue
- areas of inflammation
What happens to the outer hood in laminitis?
- shape of weight bearing surface of hoof changed
- external surface of horny sole altered
- turning up and irregular wear of toe region and thickening of the heel of the horny side
Radiographic signs - hypertrophic pulmonary osetopathy
- THORAX: nodular interstitial pattern consistent with pulmonary neoplasia
- BONE: irregular periosteal new bone formation along the diaphyses of the long bone
Another name - hypertrophic pulmonary osteopathy
Marie’s disease
If primary lesion of marie’s disease is removed, will the bone lesions regress
Yes lesions may regress
Describe marie’s disease
Periosteal new bone growth occurs on distal limb bones in association with a chronic, usually intrathoracic, inflammatory or neoplastic lesion.
- Pathogenesis unknown but theories include reflex vasomotor changes mediated by vagus increasing blood flow to extremities (periosteal oedema and hyperaemia then cause new bone growth)
Cause - White mm disease (WMD)
= a nutritional myopathy
- d/t Se and vitamin E deficiency
- usually FA/ruminants on deficient pasture
Dx - WMD
- mm biopsy (more expensive method): shows high # macrophages removing debris of degenerate mm fibres
- CK and AST blood levels (cheaper)
