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19 Cards in this Set
- Front
- Back
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What is Osteochondrosis (OC)?
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Focal or multifocal areas of defective endochondral differentiation and ossification leading to a retained cartilaginous core
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What is OCD?
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A dissecting cartilage lesion or flap formation secondary to OC
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What is a subchondral bone cyst?
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A cyst in the bone underlying a defect in articular cartilage that acts as a one-way valve-- trapping fluid in joint and leading to necrosis
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What is the epidemiology of OC?
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Young, Fast growing horses (6mo-2y)
Warmbloods, QH, STB, TB, Belgians |
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What are common sites for OC? (general anatomic)
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*1. Hock
*2. Stifle 3. Shoulder 4. Fetlock 5. Elbow 6. Growth plate (cyst) 7. Articular facets of cervical vertebrae (wobbler's) |
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What are the most common sites for OC on the Hock?
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***1. Distal intermediate ridge of the tibia
2. Lateral trochlear ridge of talus 3. Medial malleolus of tibia 4. Medial trochlear ridge of talus |
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What are the most common sites for OC on the stifle?
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****1. Lateral trochlear ridge of the distal femur
2. Patella 3. Medial femoral condyle (Subchondral bone cyst) 4. Medial trochlear ridge of femur |
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What is the most common site for shoulder OC?
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1. Caudal humeral head
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What is the most common site for OC on the fetlock?
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1. Distal condyle of MC3/MT3 (subchondral bone cyst)
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What is the Etiology of OC?
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MULTIFACTORIAL!
Genetic Nutritional Environmental Biomechanical Molecular |
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What is the most important etiology of OC?
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Rapid growth!!
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What are the nutritional factors leading to OC?
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1. High planes of nutrition coupled with a high growth rate
2. High glucose/ Insulin--response to grain 3. Low copper levels (broodmares, no supplements) 4. High phosphorus, zinc, Molybdenum |
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What are the biomechanical factors leading to OC?
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Exercise and site predilection lead to separation of the chondro-osseous junction through weakened matrix
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What are molecular factors leading to OC?
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Changes in collagen type (Increased type I (fibrous) and decreased type 2 (hyaline cartilage))
Decreased proteoglycans Changes in Growth factors Paracrine factors (PTHrp, Ihh) |
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What are clinical signs of OC?
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1. Joint effusion
2. Lameness in affected limb (mild to severe) 3. History of increased exercise leading to clinical signs |
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How do you medically treat OC?
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1. Decreased plane of nutrition (no grain/alfalfa)
2. Decreased exercise level 3. HA Joint injections |
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How do you surgically treat OCD?
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1. Arthroscopy to remove flap/debride bone
2. PDS pins: Reattach large flaps, debride necrotic bone 3. Chondrocyte/fibrin grafting (subchondral bone cysts/articular defects) 4. Micropick subchondral bone |
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What are the Post-Op instructions for an OCD?
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1. Suture removal in 2weeks, bandage for 3 weeks
2. Stall rest with increasing handwalking 3. Minimum 6 week recovery 4. HA joint injection (Adequan (PsGAG), or Legend (HA)) |
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What are prognosis for OC lesions?
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Mild to moderate: favorable return to function
Moderate to severe: Guarded for return to soundness, stifle/shoulder OC has worse prognosis |
