Difference between revisions of "Bones Inflammatory - Pathology"

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[[Osteitis]]
 
[[Osteitis]]
  
===Osteomyelitis===
+
===[[Osteomyelitis]]===
[[Image:Cattle localised osteomyelitis with sequestrum.jpg|right|thumb|100px|<small><center>Localised osteomyelitis plus sequestrum (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
 
  
*Mainly due to haematogenous spread in young animals
 
*Often as an extension from [[Joints Inflammatory - Pathology#Arthritis|suppurative arthritis]]
 
*Usually isolated: ''[[Actinomyces pyogenes]]'', [[Salmonella|''Salmonella'']], [[Escherichia coli|''E.coli'']], [[Klebsiella|''Klebsiella'']], [[:Category:Streptococcus species|''Streptococci'']]
 
*Metaphyses and epiphyses mostly affected
 
*Most infections are exacerbated by host response
 
*Pathogenesis:
 
**Prostaglandin and cytokines stimulate [[Bones - Anatomy & Physiology|osteoclastic]] bone resorption
 
**Blood vessel occlusion and tissue necrosis -> lack of removal of agent and cartilage -> cartilage thickening + persistance of infection
 
*Affected area may be surrounded by fibrous inflammatory tissue
 
*Metaphyseal abscesses may develop
 
*Sequestra may also develop -> surrounded by [[Granulation Tissue|granulation tissue]]
 
**Isolated from osteoclastic resorption
 
**May persist for long time
 
**Obstruct repair
 
 
 
*'''Vertebral osteomyelitis'''
 
**Lesions may affect the spinal cord
 
**Usually due to ''[[Actinomyces pyogenes]]''
 
**Suppurative inflammation may cause fracture of vertebral body -> dorsal displacement -> damage to spinal cord
 
**May form encapsulated abscess protruding into spinal canal -> spinal cord compression
 
 
*'''''Actinomycosis'''''
 
**= '''Lumpy jaw''' in cattle
 
**Caused by ''[[Actinomyces bovis]]''
 
***Gram positive, branching, filamentous
 
***Obligatory parasite of mucous membranes of [[Oropharynx - Anatomy & Physiology|oropharynx]]
 
***Surface tissue is usually injured for infection to occur
 
***[[Mandibular Osteomyelitis|Osteomyelitis of mandible]] -> destruction of bone -> replacement by fibrous tissue with pyogranulomatous nodules cotaining 'club colonies' of bacteria
 
***Suppurative osteomyelitis
 
***Fistulous tracts may discharge onto skin and into [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]]
 
***Excessive periosteal bone formation
 
***Greatly enlarged mandible
 
 
[[Category:Bones - Inflammatory Pathology]]
 
  
 
===Periostitis===
 
===Periostitis===
  
*Chronic periostitis - pockets of exudate and irregular new bone fomation
+
*Chronic periostitis - pockets of exudate and irregular new bone formation
  
 
[[Category:Bones - Inflammatory Pathology]]
 
[[Category:Bones - Inflammatory Pathology]]

Revision as of 12:09, 3 March 2011

Osteitis

Osteomyelitis

Periostitis

  • Chronic periostitis - pockets of exudate and irregular new bone formation

Panosteitis

Panosteitis (Image sourced from Bristol Biomed Image Archive with permission)
  • Typically young large or giant breeds
  • 75% of cases in German shepherd dogs, 5-12 months old
  • Clinical signs:
    • Shifting lameness
    • Often eosinophilia in peripheral blood
  • Usually self-limiting in one to several months
  • Grossly:
    • Foreleg long bone diaphyses affected (multiple bones in 50% of cases)
    • Increased bone formation in the medullary cavity and often in the periosteum
  • Contast with hypertrophic osteodystrophy