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Bones Degenerative - Pathology (view source)
Revision as of 19:12, 18 August 2008
, 19:12, 18 August 2008New page: {{toplink |backcolour =CDE472 |linkpage =Musculoskeletal System - Pathology |linktext =Musculoskeletal System |maplink = Musculoskeletal System (Content Map) - Pathology |pagetype =Patholo...
{{toplink
|backcolour =CDE472
|linkpage =Musculoskeletal System - Pathology
|linktext =Musculoskeletal System
|maplink = Musculoskeletal System (Content Map) - Pathology
|pagetype =Pathology
|sublink1=Bones - Pathology
|subtext1=BONES
}}
<br>
<big>
[[Bones - metabolic|'''Bones and Cartilage - metabolic diseases''']]
[[Bones - fractures|'''Bones and Cartilage - fractures''']]
</big>
===Osteoporosis (Atrophy)===
*Lesion, not a disease
*Reduction in bone mass due to reduced osteoid (bone atrophy)
*Bone resorption exceeds formation -> pathological loss of bone
*Resorbed from:
**Trabeculae, preserving the weight bearing ones until last
**Endosteal surface of cortical bone
**Along vascular channels
*Longitudinal section
**Fewer thin trabeculae
**Enlarged medulla
**Thin, porous cortex
*Bone which remains is normally mineralised
*Can be localised or generalised*Caused by:
**Starvation - in farm animals due to protein and energy deficiency
**Nutritional deficiency (calcium) and hypocalcaemia -> bone resorption
**Senility
***Physiological loss of skeletal mass with age
***May be excessive in some individuals
***Histologically - dead [[Bones - normal#Normal stucture|osteocytes and empty lacunea]]
**Physical inactivity (disuse) - muscular inactivity and reduced weight bearing, e.g. during limb casting
**Glucocorticoids
**[[Intestine - Parasites|Intestinal parasitism]] - in ruminants, malabsorption due to severe infestation
**[[General Pathology - Congenital and Neonatal Disease#Copper Deficiency|Copper deficiency]] - in lambs, calves, foals, pigs and dogs -> brittle bones
*May be reversed in young growing animals
===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|Fractures]]
**Excessive heat e.g. horn disbudding
**Neoplasia ([[Bones - hyperplastic and neoplastic#Osteosarcoma|osteosarcoma]] and [[Bones - hyperplastic and neoplastic#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 - normal#Normal structure|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#Calve Legg-Perthe's disease|Calve-Legg Perthe's disease]]
===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>]]
*May be seen radiographically
*Must be distinguished from [[Bones - hyperplastic and neoplastic#Neoplastic|neoplasia]]
*Expansile lytic masses
*Do not appear aggressive
*'''Subchondral cysts'''
**Common in horses and pigs
**Usually manifestations of [[Joints - developmental#Osteochondrosis|osteochondrosis]] and [[Joints - degenerative#Degenerative joint disease (DJD)|DJD]]
*'''Simple cysts'''
**May contain clear colourless fluid, or serosanguinous
**Wall of dense fibrous tissue, [[Bones - normal#Bone organisation|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
===Calcium hydroxylapatite deposition disease===
*Gt Dane puppies with paraplegia
*Calcium phosphate depositon has been reported in multiple diarthrodial joints of the axial and appendicular skeleton
*[[More on Calcium hydroxylapatite deposition disease|More about Calcium hydroxylapatite deposition disease]]
===Physeal dysplasia with slipped capital femoral epiphysis===
*Slipped capital femoral epiphysis seen in dogs, foals and calves
*Associated with severe trauma
*Pigs – manifestation of [[Joints - developmental#Osteochondrosis|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 [[Bones Developmental - Pathology#Physitis|physitis]]
*[[More about Physeal dysplasia]]
|backcolour =CDE472
|linkpage =Musculoskeletal System - Pathology
|linktext =Musculoskeletal System
|maplink = Musculoskeletal System (Content Map) - Pathology
|pagetype =Pathology
|sublink1=Bones - Pathology
|subtext1=BONES
}}
<br>
<big>
[[Bones - metabolic|'''Bones and Cartilage - metabolic diseases''']]
[[Bones - fractures|'''Bones and Cartilage - fractures''']]
</big>
===Osteoporosis (Atrophy)===
*Lesion, not a disease
*Reduction in bone mass due to reduced osteoid (bone atrophy)
*Bone resorption exceeds formation -> pathological loss of bone
*Resorbed from:
**Trabeculae, preserving the weight bearing ones until last
**Endosteal surface of cortical bone
**Along vascular channels
*Longitudinal section
**Fewer thin trabeculae
**Enlarged medulla
**Thin, porous cortex
*Bone which remains is normally mineralised
*Can be localised or generalised*Caused by:
**Starvation - in farm animals due to protein and energy deficiency
**Nutritional deficiency (calcium) and hypocalcaemia -> bone resorption
**Senility
***Physiological loss of skeletal mass with age
***May be excessive in some individuals
***Histologically - dead [[Bones - normal#Normal stucture|osteocytes and empty lacunea]]
**Physical inactivity (disuse) - muscular inactivity and reduced weight bearing, e.g. during limb casting
**Glucocorticoids
**[[Intestine - Parasites|Intestinal parasitism]] - in ruminants, malabsorption due to severe infestation
**[[General Pathology - Congenital and Neonatal Disease#Copper Deficiency|Copper deficiency]] - in lambs, calves, foals, pigs and dogs -> brittle bones
*May be reversed in young growing animals
===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|Fractures]]
**Excessive heat e.g. horn disbudding
**Neoplasia ([[Bones - hyperplastic and neoplastic#Osteosarcoma|osteosarcoma]] and [[Bones - hyperplastic and neoplastic#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 - normal#Normal structure|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#Calve Legg-Perthe's disease|Calve-Legg Perthe's disease]]
===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>]]
*May be seen radiographically
*Must be distinguished from [[Bones - hyperplastic and neoplastic#Neoplastic|neoplasia]]
*Expansile lytic masses
*Do not appear aggressive
*'''Subchondral cysts'''
**Common in horses and pigs
**Usually manifestations of [[Joints - developmental#Osteochondrosis|osteochondrosis]] and [[Joints - degenerative#Degenerative joint disease (DJD)|DJD]]
*'''Simple cysts'''
**May contain clear colourless fluid, or serosanguinous
**Wall of dense fibrous tissue, [[Bones - normal#Bone organisation|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
===Calcium hydroxylapatite deposition disease===
*Gt Dane puppies with paraplegia
*Calcium phosphate depositon has been reported in multiple diarthrodial joints of the axial and appendicular skeleton
*[[More on Calcium hydroxylapatite deposition disease|More about Calcium hydroxylapatite deposition disease]]
===Physeal dysplasia with slipped capital femoral epiphysis===
*Slipped capital femoral epiphysis seen in dogs, foals and calves
*Associated with severe trauma
*Pigs – manifestation of [[Joints - developmental#Osteochondrosis|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 [[Bones Developmental - Pathology#Physitis|physitis]]
*[[More about Physeal dysplasia]]