Difference between revisions of "Joints Developmental - Pathology"
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**-> Thickening of femoral head + degeneration of [[Joints - normal#Articular cartilage|articular cartilage]] | **-> Thickening of femoral head + degeneration of [[Joints - normal#Articular cartilage|articular cartilage]] | ||
**[[Musculoskeletal terminology|Eburnation]] | **[[Musculoskeletal terminology|Eburnation]] | ||
| − | *Predisposes to [[Joints - | + | *Predisposes to [[Joints Degenerative - Pathology#Degenerative joint disease (DJD)|DJD]] |
*Round ligament of femoral head may rupture -> luxation | *Round ligament of femoral head may rupture -> luxation | ||
| Line 36: | Line 36: | ||
**Normally, they unite between 4-6 months of life | **Normally, they unite between 4-6 months of life | ||
*May partially or totally separate from each other | *May partially or totally separate from each other | ||
| − | *Intra-articular irritation -> [[Joints - | + | *Intra-articular irritation -> [[Joints Degenerative - Pathology#Degenerative joint disease (DJD)|DJD]] with [[Musculoskeletal terminology|osteophyte]] formation within the joint |
| Line 66: | Line 66: | ||
**Lysis → bone cysts | **Lysis → bone cysts | ||
**Focal disruption of [[Bones - normal#Bone development|endochondral ossification]] | **Focal disruption of [[Bones - normal#Bone development|endochondral ossification]] | ||
| − | **-> Angular limb deformities and [[Joints - | + | **-> Angular limb deformities and [[Joints Degenerative - Pathology#Degenerative joint disease (DJD)|degenerative joint disease]] |
**May be present together with '''synovitis''' | **May be present together with '''synovitis''' | ||
**Predilection sites: | **Predilection sites: | ||
Revision as of 19:45, 18 August 2008
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Hip dysplasia
- Mainly large and giant dog breeds, especially with stocky conformations
- Seen in cattle - Herefords
- Subluxation of hip joint due to maldevelopment
- Not present at bith
- Inherited + environmental factor involvement (nutrition, exercise)
- Pelvic muscles are behind the bone development in rapidly growing dogs -> lack of restraint of the joint -> excess movement before acetabulum is fully mature
- Usually develops within first 6 months of life
- Varying degrees of severity
- Pathogenesis:
- Joint laxity / acetabular dysplasia
- -> Flattened femoral head +/- mild or severe periarticular osteophyte formation
- -> Thickening of femoral head + degeneration of articular cartilage
- Eburnation
- Predisposes to DJD
- Round ligament of femoral head may rupture -> luxation
Elbow dysplasia
- = Ununited anconeal process
- In dogs, especially German Shepherd Dogs, St. Bernards, Labradors
- Occurs during first few years of life
- Failure of anconeal centre of ossification to unite with the ulna
- Normally, they unite between 4-6 months of life
- May partially or totally separate from each other
- Intra-articular irritation -> DJD with osteophyte formation within the joint
Osteochondrosis
- Defect in cartilage growth (i.e. dyschondroplasia)
- In growing animals: large breeds of dogs (4-8 months), pigs (5-7 months) and horses (weeks - 2 years)
- Involves both the growth plate and the immature joint cartilage
- Multifactorial:
- Trauma
- Genetic
- Rapid growth
- Ischaemia
- Nutritional
- Essentially idiopathic
- Failure of endochondral ossification
- Lesions bilateral in 70% of cases but lameness often unilateral, sometimes no clinical signs
- Some authors consider this condition more generalised, in which case e.g. ununited anconeal process would be part of osteochondrosis syndrome
Different manifestations include:
- 1. Osteochondrosis dissecans (OCD):
- Retained cartilage cores
- White, wedge-shaped areas of retained cartilage in the metaphysis
- Clefts -> separation of cartilage from bone -> flaps or free joint mice
- May interfere with joint function
- Lysis → bone cysts
- Focal disruption of endochondral ossification
- -> Angular limb deformities and degenerative joint disease
- May be present together with synovitis
- Predilection sites:
- In dogs:
- Proximal humerus
- Lateral femoral condyle
- Coronoid process of ulna
- In pigs:
- Humeral and medial femoral condyles
- Anconeal process of elbow
- In horses:
- Medial femoral condyle
- Distal tibia
- In dogs:
- Osteochondrosis dissecans in dogs:
- Grossly:
- Lesion in central part of the caudal aspect of developing ossification centre in humeral head
- Histologcally:
- Lesion filled with granulation tissue (fibroplasia)
- Surrounding thickened bone spicules
- Cap of thickened articular cartilage over the defect
- -> May fragment - joint mice
- Calcified cartilage fragments may be in the posterior pocket of joint capsule
- May grow through synovial fluid nourishment
- Grossly:
- Retained cartilage cores
- 2. Epiphysiolysis
- Not associated with retention of cartilage
- Separation of epiphysis from the metaphysis
- Likely to be due to trauma to degenerated growth plate
- Possibly the basis of ununited anconeal process and ununited coronoid process in dogs
Arthrogryposis
- Persistent congenital flexure of a joint in conjunction with muscle contraction
- Caused by:
- Inactivity or paralysis in utero
- Spinal dysraphism
- Intrauterine viral infections
- Toxic plants (poison hemlock, lupine)
- Cause persitent contraction of uterus -> fetal compression
- Arthrogryposis and palatoschisis in Charolais cattle