Developmental Orthopaedic Disease Flashcards
What can cause developmental orthopaedic disease?
*Genetics
*Trauma
*Abnormal biomechanics
*Nutrition - mineral deficiency, excessive energy source
What can developmental orthopaedic disease lead to?
*Lameness issues
*Welfare concerns
*Reduced production
*Ethical questions around breeding
What are some equine developmental orthopaedic disease?
*Osteochondrosis
*Physitis
*Angular limb deformities
*Flexural deformities
What are some canine developmental orthopaedic disease?
*Osteochondrosis
*Angular limb deformities
*Hip / elbow dysplasia
*Legg calve perthes disease
*Hypertrophic osteodystrophy
What are developmental orthopaedic diseases of production animals?
*Osteochondrosis
*Angular limb deformities
*Flexural deformities
What can disturbance in one or more component of endochondral ossification lead to?
*Alter rates of growth
*Affect direction of growth leading to abnormal angulation (e.g. valgus/varus)
*Lead to dysfunction of cartilage (Abnormal cartilage development
What are possible factors of developmental orthopaedic disease?
*Rapid growth - large, fast-growing breeds
*Nutrition - high energy / protein intake
*Mineral imbalance - excessive calcium / phosphorus, Low copper diets
*Trauma / abnormal exercise loads
*Genetic predisposition
What is the pathogenesis of osteochondrosis?
- Premature interruption to vascular supply
- Abnormal chondrocyte maturation
- Defective matrix production
What does disruption to vascular supply to cartilage cause?
*Leads to islands of retained / necrotic cartilage - similar to OC-lesions
What does abnormal cartilage maturation cause?
*Chondrocytes from osteochondritic lesions show signs of up-regulation then loss of viability
*Abnormally elevated signalling pathways affect maturation+ ossification in cartilage and subchondral bone
How does defective extracellular matrix production occur?
- Increased ECM production around activated chondrocytes involved in early repair process in OC-lesions
- Alterations in collagen expression from chondrocytes in OC-lesions may lead to abnormal biomechanical properties
- Increased expression of proteases (cathepsins) in OC-lesions
What does osteochondrosis involve?
1.A vascular incident leading to cartilage island retention
2. A reparative phase which exhausts the chondrocytes and then failure to undergo hypertrophy and apoptosis as part of normal endochondral ossification
3. The reparative response results in abnormal extracellular matrix production and enzyme release which affects the biochemical and hence biomechanical properties of cartilage
4. Cartilage is then prone to separation/fragmentation (e.g. OCD) or infolding to form a cyst (e.g. OCLL)
What presentation of osteochondrosis is seen with shear forces across the cartilage?
Fragmentation / flaps are found
What presentation of osteochondrosis is seen with compressive forces?
Cysts are found = OCLL
How is osteochondrosis diagnosed?
*Signalment - young fast growing animals
*CLinical signs
*Diagnostic imaging