Difference between revisions of "Bones Degenerative - Pathology"

Revision as of 11:57, 3 March 2011

Bone cysts (Image sourced from Bristol Biomed Image Archive with permission)

May be seen radiographically
Must be distinguished from neoplasia
Expansile lytic masses
Do not appear aggressive
Subchondral cysts
- Common in horses and pigs
- Usually manifestations of osteochondrosis and DJD
Simple cysts
- May contain clear colourless fluid, or serosanguinous
- Wall of dense fibrous tissue, woven or lamellar bone
Aneurysmal bone cysts
- Expansie lesions
- Arise from disturbance of vascular tissue of bone marrow
- Grossly:
  - Appear as blood filled sponge
  - Spaces separated by fibrous trabeculae
- Histologically:
  - Proliferation of undifferentiated mesenchymal cell with multinucleated osteoclast-like cells
  - Haemorrhage and haemosiderosis
Radiography is essential to help differentiate with cavity of a neoplasm

Gt Dane puppies with paraplegia
Calcium phosphate depositon has been reported in multiple diarthrodial joints of the axial and appendicular skeleton
More about Calcium hydroxylapatite deposition disease

Slipped capital femoral epiphysis seen in dogs, foals and calves
Associated with severe trauma
Pigs – manifestation of osteochondrosis with only minimal trauma required
Most common type of physeal fracture in small animals and the proximal femur is the most common site
In horses, physeal dysplasia is synonymus with physitis
More about Physeal dysplasia

@@ Line 8: / Line 8: @@
 ===[[Osteoporosis]] (Atrophy)===
-===Osteosis===
+===[[Osteosis]]===
-*Also called '''Aseptic necrosis''' or '''Ischaemic necrosis'''
-*Degeneration and necrosis of osseous tissue
-*Due to bone marrow pressure and ischaemia resulting from
-**[[Bones Fractures - Pathology|Fractures]]
-**Excessive heat e.g. horn disbudding
-**Neoplasia ([[Bones Hyperplastic and Neoplastic - Pathology#Osteosarcoma|osteosarcoma]] and [[Bones Hyperplastic and Neoplastic - Pathology#Lymphosarcoma|lymphosarcoma]])
-*Grossly:
-**Necrotic bone difficult to recognise
-**Sometimes, periosteum becomes dry, dull and detaches easily
-**On longitudinal section
-***Yellow-white necrotic bone
-***Scattered cancellous and endosteal bone
-*Histologically:
-**Empty [[Bones - Anatomy & Physiology|lacunae or contain dead osteocytes]]
-**Matrix remains mineralised
-*Necrotic bone is slowly resorbed, sequstered or covered by new woven bone
-*Persists
-*May not be detected radiographically
-*Associated with [[Joints Degenerative - Pathology#Calve Legg-Perthe's disease|Calve-Legg Perthe's disease]]
-[[Category:Bones - Degenerative Pathology]]
 ===Bone cysts===
 [[Image:Bone cysts dog.jpg|right|thumb|100px|<small><center>Bone cysts (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]