Difference between revisions of "Joints Degenerative - Pathology"

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#redirect[[:Category:Joints - Degenerative Pathology]]
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|linkpage =Musculoskeletal System - Pathology
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|linktext =Musculoskeletal System
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|maplink = Musculoskeletal System (Content Map) - Pathology
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|pagetype =Pathology
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|sublink1=Joints - Pathology
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|subtext1=JOINTS
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<br>
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===Degenerative joint disease (DJD)===
 +
[[Image:DJD horse.jpg|right|thumb|100px|<small><center>DJD in a horse (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
 +
*'''Osteoarthritis, osteoarthrosis'''
 +
*Due to acceleration of normal ageing process - wear and tear
 +
*Destructive disease leading to:
 +
**Loss of weight-bearing [[Joints - Anatomy & Physiology#Articular cartilage|articular cartilage]]
 +
**Erosion, fibrillation of cartilage
 +
***Clefts in the cartilage, perpendicular to the surface
 +
**Complete exposure of underlying bone
 +
***Bone appears polishes, dense - [[Musculoskeletal Terminology - Pathology|eburnation]]
 +
***Radiographically - joint space reduction due to loss of cartilage
 +
**[[Musculoskeletal Terminology - Pathology|Osteophyte]] formation at joint margins
 +
**Remodelling of adjacent bone
 +
**Brown/yellow discolouration
 +
**Synovial hypertrophy
 +
**Capsular fibrosis
 +
*May affect one or multiple joints
 +
*May or may not be symptomatic
 +
*Pathogenesis:
 +
**Not entirely clear but linked to loss of [[Joints - Anatomy & Physiology#Articular cartilage|proteoglycans]] and subsequent lubrication
 +
**Increased water content due to improper binding -> softening of cartilage = chondromalacia
 +
 
 +
*Predisposing factors:
 +
**Persistent trauma
 +
**Joint instability / dysplasia
 +
***[[Joints Degenerative - Pathology#Luxations and subluxations|Luxations and subluxations]]
 +
***[[Joints Developmental - Pathology#Hip dysplasia|Hip dysplasia]]
 +
***[[Joints Developmental - Pathology#Elbow dysplasia|Elbow dysplasia]]
 +
**Conformational abnormalities / congenital malformations
 +
**[[Joints Developmental - Pathology#Osteochondrosis|Osteochondrosis dissecans]]
 +
**Intra-articular fractures
 +
**[[Joints Degenerative - Pathology#Calve Legg-Perthe's disease|Calve Legg-Perthe's disease]]
 +
 
 +
 
 +
===Luxations and subluxations===
 +
 
 +
====Patellar====
 +
 
 +
*In stifle joints of dogs and horses
 +
*Possibly inherited
 +
*'''Small''' dog breeds:
 +
**'''Medial''' luxation
 +
**Due to underdevelopment of medial femoral condyle
 +
*'''Large''' dog breeds and '''horses''':
 +
**'''Lateral''' luxation
 +
 
 +
 
 +
====Atlantoaxial====
 +
 
 +
*In dogs, calves, horses and goats
 +
*Miniature dog breeds:
 +
**Failure of fusion of odontoid process to rest of axis
 +
*Calves:
 +
**Aplasia or hypoplasia of odontoid process
 +
 
 +
 
 +
====Temporomandibular====
 +
 
 +
*In dogs, particularly Basset Hounds, Irish Setters
 +
*Normal movement of mandibular coronoid process is interfered with by zygomatic arch
 +
*Happens on one side -> open jaw locking
 +
 
 +
 
 +
===Calve Legg-Perthe's disease===
 +
 
 +
*Almost exlusively in small dogs, particularly terriers and poodles
 +
*Clinical signs appear at age of 4-11 months
 +
*Grossly:
 +
**[[Osteosis|Aseptic ischaemic necrosis]] in central parts of femoral head
 +
***Possibly due to occlusion of blood vessels
 +
**Fragmentation of [[Bones - Anatomy & Physiology|trabecular bone]]
 +
**Collapse of femoral head
 +
**Revascularisation of femoral head
 +
**Formation of new bone and [[Musculoskeletal Terminology - Pathology|osteophyte]] formation around femoral head and acetabular rim prior to old bone reabsorption
 +
**-> severe degenerative arthropathy
 +
 
 +
 
 +
===Degenerative arthropathy===
 +
 
 +
*In older dogs (8+ years)
 +
*Occurs bilaterally
 +
*In shoulders
 +
*?Due to gradual atrophy of muscles with age -> joint laxity
 +
 
 +
 
 +
===Traumatic injuries===
 +
 
 +
*Sudden
 +
*Varying severity
 +
*Acute injuries:
 +
**Sprains
 +
***Minor - resolved without any consequences
 +
***More severe may result in persistent capsular and ligament laxity -> degenerative arthrosis -> impaired function
 +
**Subluxations
 +
**Luxations
 +
**Intra-articular fractures
 +
***[[Bones Fractures - Pathology#Fracture repair|Fracture healing]] may cause discontinuity of the articular surfaces
 +
**Puncture wounds to foot may allow infection to travel to [[Joints Inflammatory - Pathology|joints]], bursae and tendon sheaths
 +
**Haemorrhage into joint
 +
***May occur in animals with clotting defects without special trauma
 +
****Usually polyaricular
 +
****Recurrent
 +
****May cause pitting of articular surfaces -> degenerative arthrosis
 +
 
 +
 
 +
===Nutritional diseases===
 +
 
 +
====Hypervitaminosis A====
 +
 
 +
*See [[Hypervitaminosis A|metabolic diseases of bones]]
 +
*May cause spondylosis of cervical vertebrae
 +
*Mainly on dorsolateral surface
 +
*Also in elbow and shoulder joints -> fixation of joint
 +
*May resolve with changes of diet
 +
 
 +
 
 +
===Disc protrusion===
 +
[[Image:Intervertebral disc degeneration.jpg|right|thumb|100px|<small><center>Intervertebral disc degeneration (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
 +
*Occurs mainly in dogs
 +
*Almost always '''dorsal''' protrusion due to eccentric position of [[Joints - Anatomy & Physiology#Fibrocartilagenous joints|''nucleus pulposus'']]
 +
*Main sites are '''cervical and lumbar''' regions
 +
**Thoracic vertebrae have [[Joints - Anatomy & Physiology#Fibrocartilagenous joints|conjugal ligaments]]
 +
*Degeneration precedes protrusion (two patterns):
 +
**'''Chondroid'''
 +
***In chondrodystrophic breeds
 +
***Concurrent calcification of [[Intervertebral disc degeneration|degenerated ''nucleus pulposus'']]
 +
***Progressive loosening and fragmentation of overlying ''annulus fibrosis'' fibres
 +
****Damaged by both compressive and rotational forces
 +
***Predisposing degeneration of the discs occurs by one year of age in most of the dogs
 +
***Protrusion usually occurs in males, 3-6 years of age
 +
***'''Sudden complete protrusion''' -> severe damage to spinal cord in the area
 +
***Widespread necrosis and haemorrhage
 +
***Extruded material is gritty, hemorrhagic or “cheesy”
 +
**'''Fibroid'''
 +
***In non-chondrodystrophic breeds, horses, pigs
 +
***Usually occurs later in life
 +
***Pathogenesis:
 +
****Progressive dehydration and collagenisation of ''nucleus pulposus''
 +
****Fraying and fragmentation of lamellar ''annulus fibrosis'' fibres
 +
**** -> Attempts to repair by fibrosis
 +
**** -> Weak area in the annulus
 +
**** -> '''Partial protrusion''' (rarely may calcify) of nucleus into spinal canal
 +
*****May be dorsal or lateral
 +
**** -> Pressure on spinal cord
 +
**** -> Demyelination of white matter
 +
**** -> Progressive weakness of structures innervated distally to the lesion
 +
***Disk material may enter blood vessels causing fibrocartilagenous embolism
 +
****May present without any disk symptoms
 +
 
 +
 
 +
*'''Sudden protrusion''' can occur in any breed due to traumatic compression of spinal cord
 +
 
 +
 
 +
 
 +
===Cervical spinal stenosis===
 +
 
 +
*Usually funnel-shaped
 +
*Stenosis in dorso-ventral plane
 +
*May occur at more than one site
 +
*Predisposed in some breeds: Great Dane, Doberman, Basset Hound, Irish Wolfhound, Old English Sheepdog
 +
*Clinical signs: cervical pain -> ataxia -> quadriplegia
 +
 
 +
 
 +
===Cervicospinal arthropathy===
 +
 
 +
* = "'''Wobbler'''" in horses
 +
*Usually presents in first two years of life
 +
*Mainly in fast growing thouroughbreds
 +
*Most common site is C3-C4, can occur anywhere
 +
*Abnormal laxity between the vertebrae + cervical vertebral malformation may be evident
 +
*[[Musculoskeletal Terminology - Pathology|Osteophyte formation]] at edges of synovial components of joint
 +
*Some due to stenosis of neural canal later in life (1-4 years of age)
 +
*Clinical signs:
 +
**Ataxia - hindlimbs more affected
 +
*Presumed cause is rapid growth
 +
 
 +
 
 +
===Spondylosis===
 +
[[Image:Spondylosis.jpg|right|thumb|100px|<small><center>Spondylosis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
 +
 
 +
*Often in bulls and dogs, occurs also in horses, cats and pigs
 +
*[[Musculoskeletal Terminology - Pathology|Osteophyte]] formation on ventral aspect of vertebrae
 +
**Often around lumbar region
 +
**Adjacent to intervertebral spaces
 +
**Varies in size - small spurs -> 'bridges' between vertebrae
 +
**May extend over few vertebrae
 +
*Pathogenesis:
 +
**Repeated abnormal movement between joints -> stress
 +
** -> Degeneration of [[Joints - Anatomy & Physiology#Fibrocartilagenous joints|''annulus fibrosis'']]
 +
** -> [[Musculoskeletal Terminology - Pathology|Osteophyte]] formation
 +
*In dogs usually no symptoms
 +
*In bulls may cause inability to mount
 +
*In severe cases repeated damage may progress to recurrent posterior weakness and ataxia in conjuction with fractures of spondylitic and vertebral bone
 +
 
 +
 
 +
===Cranial cruciate ligament rupture===
 +
 
 +
*Autoantibodies against collagens seen in the joint fluid – no relationship to the disease (ie: not an autoimmune disease) – can be seen in any joint disease
 +
 
 +
 
 +
===Steroid arthropathy===
 +
 
 +
*From glucocorticoids injected into joint as antiinflammatories
 +
*Injection sometimes causes rapid progression of degeneration
 +
*Glucocortyicois suppress anabolic effect of chondrocytes -> reduction of cartilage matrix syhthesis -> proteoglycan depletion -> slower repair

Revision as of 12:21, 3 March 2011


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()Map MUSCULOSKELETAL SYSTEM (Map)
JOINTS



Degenerative joint disease (DJD)

DJD in a horse (Image sourced from Bristol Biomed Image Archive with permission)
  • Osteoarthritis, osteoarthrosis
  • Due to acceleration of normal ageing process - wear and tear
  • Destructive disease leading to:
    • Loss of weight-bearing articular cartilage
    • Erosion, fibrillation of cartilage
      • Clefts in the cartilage, perpendicular to the surface
    • Complete exposure of underlying bone
      • Bone appears polishes, dense - eburnation
      • Radiographically - joint space reduction due to loss of cartilage
    • Osteophyte formation at joint margins
    • Remodelling of adjacent bone
    • Brown/yellow discolouration
    • Synovial hypertrophy
    • Capsular fibrosis
  • May affect one or multiple joints
  • May or may not be symptomatic
  • Pathogenesis:
    • Not entirely clear but linked to loss of proteoglycans and subsequent lubrication
    • Increased water content due to improper binding -> softening of cartilage = chondromalacia


Luxations and subluxations

Patellar

  • In stifle joints of dogs and horses
  • Possibly inherited
  • Small dog breeds:
    • Medial luxation
    • Due to underdevelopment of medial femoral condyle
  • Large dog breeds and horses:
    • Lateral luxation


Atlantoaxial

  • In dogs, calves, horses and goats
  • Miniature dog breeds:
    • Failure of fusion of odontoid process to rest of axis
  • Calves:
    • Aplasia or hypoplasia of odontoid process


Temporomandibular

  • In dogs, particularly Basset Hounds, Irish Setters
  • Normal movement of mandibular coronoid process is interfered with by zygomatic arch
  • Happens on one side -> open jaw locking


Calve Legg-Perthe's disease

  • Almost exlusively in small dogs, particularly terriers and poodles
  • Clinical signs appear at age of 4-11 months
  • Grossly:
    • Aseptic ischaemic necrosis in central parts of femoral head
      • Possibly due to occlusion of blood vessels
    • Fragmentation of trabecular bone
    • Collapse of femoral head
    • Revascularisation of femoral head
    • Formation of new bone and osteophyte formation around femoral head and acetabular rim prior to old bone reabsorption
    • -> severe degenerative arthropathy


Degenerative arthropathy

  • In older dogs (8+ years)
  • Occurs bilaterally
  • In shoulders
  • ?Due to gradual atrophy of muscles with age -> joint laxity


Traumatic injuries

  • Sudden
  • Varying severity
  • Acute injuries:
    • Sprains
      • Minor - resolved without any consequences
      • More severe may result in persistent capsular and ligament laxity -> degenerative arthrosis -> impaired function
    • Subluxations
    • Luxations
    • Intra-articular fractures
    • Puncture wounds to foot may allow infection to travel to joints, bursae and tendon sheaths
    • Haemorrhage into joint
      • May occur in animals with clotting defects without special trauma
        • Usually polyaricular
        • Recurrent
        • May cause pitting of articular surfaces -> degenerative arthrosis


Nutritional diseases

Hypervitaminosis A

  • See metabolic diseases of bones
  • May cause spondylosis of cervical vertebrae
  • Mainly on dorsolateral surface
  • Also in elbow and shoulder joints -> fixation of joint
  • May resolve with changes of diet


Disc protrusion

Intervertebral disc degeneration (Image sourced from Bristol Biomed Image Archive with permission)
  • Occurs mainly in dogs
  • Almost always dorsal protrusion due to eccentric position of nucleus pulposus
  • Main sites are cervical and lumbar regions
  • Degeneration precedes protrusion (two patterns):
    • Chondroid
      • In chondrodystrophic breeds
      • Concurrent calcification of degenerated nucleus pulposus
      • Progressive loosening and fragmentation of overlying annulus fibrosis fibres
        • Damaged by both compressive and rotational forces
      • Predisposing degeneration of the discs occurs by one year of age in most of the dogs
      • Protrusion usually occurs in males, 3-6 years of age
      • Sudden complete protrusion -> severe damage to spinal cord in the area
      • Widespread necrosis and haemorrhage
      • Extruded material is gritty, hemorrhagic or “cheesy”
    • Fibroid
      • In non-chondrodystrophic breeds, horses, pigs
      • Usually occurs later in life
      • Pathogenesis:
        • Progressive dehydration and collagenisation of nucleus pulposus
        • Fraying and fragmentation of lamellar annulus fibrosis fibres
        • -> Attempts to repair by fibrosis
        • -> Weak area in the annulus
        • -> Partial protrusion (rarely may calcify) of nucleus into spinal canal
          • May be dorsal or lateral
        • -> Pressure on spinal cord
        • -> Demyelination of white matter
        • -> Progressive weakness of structures innervated distally to the lesion
      • Disk material may enter blood vessels causing fibrocartilagenous embolism
        • May present without any disk symptoms


  • Sudden protrusion can occur in any breed due to traumatic compression of spinal cord


Cervical spinal stenosis

  • Usually funnel-shaped
  • Stenosis in dorso-ventral plane
  • May occur at more than one site
  • Predisposed in some breeds: Great Dane, Doberman, Basset Hound, Irish Wolfhound, Old English Sheepdog
  • Clinical signs: cervical pain -> ataxia -> quadriplegia


Cervicospinal arthropathy

  • = "Wobbler" in horses
  • Usually presents in first two years of life
  • Mainly in fast growing thouroughbreds
  • Most common site is C3-C4, can occur anywhere
  • Abnormal laxity between the vertebrae + cervical vertebral malformation may be evident
  • Osteophyte formation at edges of synovial components of joint
  • Some due to stenosis of neural canal later in life (1-4 years of age)
  • Clinical signs:
    • Ataxia - hindlimbs more affected
  • Presumed cause is rapid growth


Spondylosis

Spondylosis (Image sourced from Bristol Biomed Image Archive with permission)
  • Often in bulls and dogs, occurs also in horses, cats and pigs
  • Osteophyte formation on ventral aspect of vertebrae
    • Often around lumbar region
    • Adjacent to intervertebral spaces
    • Varies in size - small spurs -> 'bridges' between vertebrae
    • May extend over few vertebrae
  • Pathogenesis:
  • In dogs usually no symptoms
  • In bulls may cause inability to mount
  • In severe cases repeated damage may progress to recurrent posterior weakness and ataxia in conjuction with fractures of spondylitic and vertebral bone


Cranial cruciate ligament rupture

  • Autoantibodies against collagens seen in the joint fluid – no relationship to the disease (ie: not an autoimmune disease) – can be seen in any joint disease


Steroid arthropathy

  • From glucocorticoids injected into joint as antiinflammatories
  • Injection sometimes causes rapid progression of degeneration
  • Glucocortyicois suppress anabolic effect of chondrocytes -> reduction of cartilage matrix syhthesis -> proteoglycan depletion -> slower repair