OCD in horses Flashcards
OCD/OC =
OSTEOCHONDRITIS DISSECANS
what is the pathophysiology behind OCd?
There is a disturbance of cellular differentiantion in the growing cartilage.
- Persistent hypertrophic stage
- Improper vascular supply of the young cartilage.
What are the different types of weaknesses in the cartilages?
- Flattening of the joint surface
- Cartilage flap without rad. changes
- Cartilage flaps free in joint
- Cartilage with subchondral bone changes
- OCD fragments free in joint
What can be a result of OCD?
- Resorption
- Incorporation in joint capsule,
- Stays in joint -> Ossification, OCD fragments
- Riss in joint cartilage –> resorption -> SBC
What are the causes of OCD?
- Genetic predisposition (large breeds?) not in pony
- Environmental influences
- Nutrition - Imbalance in feeding / tak. imbalance
- Endocrine factors
- Biomechanic forces, Trauma
What are the predilection sites of OCD? (in general)
Neck facet joints, shoulder, fetlock, femoropatellar joint, hock .
What are the clinical forms?
- Osteochondrosis (OC)
- Osteochondritis dissecans (OCD)
- Subchondral Bone Cysts
typical predielction sites of the hock joint:
DIRT / dist. Tibia cran. Intermed.
Lateral Talus Trochlea distal aspect
Medial Malleolus
typical predielction sites of the stifle:
Lateral femoral trochlea
typical predielction sites of the
Facet joints cervical region
typical predielction sites of the fetlock joint:
Dorsal MCIII/MTIII Crista sagittalis
typical predielction sites of the shoulder:
Caudal part of humerus head
Cavitas Glenoidalis, + caudodistal ridge of Scapula
typical predielction sites of the shoulder:
Caudal part of humerus head
Cavitas Glenoidalis, + caudodistal ridge of Scapula
Treatement of OCD?
- Wait if the foal are younger than 1 year.
- Conservative treatment
- Surgery
Subchondral Bone Cysts , how does the cyst develop?
Different ways :
- Juvenile form similar to OCD.
- Tear in the weight-bearing cartilage.
- Pressure, enzymes develop a cyst.
- Mostly adult horses, but you can see it in fowls because of disturbance in bone formation.
What can you find inside the cyst lining?
Fibrous tissue
Fibrocartilage
Necrotic bone
Sclerotic border around the cyst will develop which you can see on the Xray, more minerals around it.
Cloaca communication with the joint.
What are the predilaction sites of the cysts?
- Medial Femoral Condyle
- Distal MCIII/MTIII (med. or lat. condylus or crista sagittalis)
- Medial proximal Radius epiphysis
- Distal phalanx
- Scapula cavum glenoidale
- White color on the X-rays
What are the clinical signs of Subchondral Bone Cysts?
- Lame after work, better with rest
- More frequent: 6 M – 2 Y, But: you will find it also in older horses
- Lameness intermittent if not acute
- Receive if starts training again
- Sometimes acutely lame
- medial Femur condylus
- Distal MCIII
- Joint effusion not always present
What are the treatment of Subchondral Bone Cysts?
Different surgical treatment regimens:
- Steroid inj. Into the cyst – comes from human medicine in children
- Extra-articular approach (drilling) and Parathormon Hydrogel (PTH)
- Enucleation of the cyst inside lining
- Defect filled out with TGF-1+ Ca activated thrombin +fibrinogen
- Autologous Osteochondral Transplantation (Mosaicplasty)
- Position screw through the cyst
