📝 STANDARD DESCRIPTION:
Most COMPLEX joint of the body.
Type: Synovial — actually 3 joints in one (compound):
1. Femoro-tibial joint (medial & lateral compartments).
2. Femoro-patellar joint.
3. (No tibiofibular in ox because fibula is reduced.)
Special structures:
- 2 MENISCI (medial & lateral) — C-shaped fibrocartilage cushions between femur & tibia.
- 2 CRUCIATE LIGAMENTS (Cranial & Caudal) — cross inside the joint (X-shape); prevent forward/backward sliding of tibia.
- 2 COLLATERAL LIGAMENTS (medial & lateral) — outside the joint; prevent side-to-side movement.
- 3 PATELLAR LIGAMENTS (in horse/ox) — anchor patella to tibial tuberosity.
Movement: Mainly flexion-extension (hinge). Some rotation when flexed.
📚 DETAILED DESCRIPTION:
STIFLE — the 'knee' of animals
The stifle is the largest, most complex joint of the body. Anatomically it is 3 joints sharing one capsule.
3 SUB-JOINTS:
1. Femoro-tibial (medial + lateral parts) — main weight-bearing.
2. Femoro-patellar — front of stifle, where patella slides over the trochlea.
3. (Proximal tibio-fibular — present in dog only; reduced in ox/horse.)
MENISCI (Cartilage 'cushions'):
Two C-shaped pads of fibrocartilage between the femur and tibia (medial + lateral). They:
• Deepen the tibial articular surface.
• Absorb shock and distribute weight.
• Anchored at front and back to the tibia by short ligaments.
(In dogs the medial meniscus often tears with cruciate rupture.)
CRUCIATE LIGAMENTS (inside the joint):
Two strong bands crossing each other inside the joint cavity:
• Cranial Cruciate Ligament (CrCL): Prevents tibia sliding forward.
• Caudal Cruciate Ligament (CdCL): Prevents tibia sliding backward.
COLLATERAL LIGAMENTS (outside):
• Medial Collateral — prevents inward bending.
• Lateral Collateral — prevents outward bending.
PATELLAR LIGAMENTS (in front, in horse/ox):
3 strong bands from the patella to the tibial tuberosity (medial, middle, lateral). The medial one is the focus of the equine stay apparatus and the desmotomy operation.
JOINT POUCHES: The stifle has 3 large synovial pouches (one for each sub-joint) — the lateral femoro-tibial pouch is a common site of joint disease in cattle and is the entry point for arthrocentesis.
// COMPARATIVE ANALYSIS
| HORSE |
Has the medial patellar ligament and parapatellar fibrocartilage that lock the stifle in extension (stay apparatus). |
| DOG |
Has only ONE patellar ligament. Cranial Cruciate Ligament rupture (CCL rupture) is the most common stifle injury. |
CLINICAL RELEVANCE
Cranial Cruciate Ligament Rupture (Dog): Sudden weight-bearing twist tears the CCL → tibia slides forward (positive 'cranial drawer test'). Common in obese mid-aged dogs.
Upward Fixation of Patella → Medial Patellar Desmotomy (HORSE): Operation in which the medial patellar ligament is cut to relieve the stuck ligament locking the stifle.
Meniscal Tear: Audible 'click' on stifle flexion; often accompanies CCL rupture in dogs.
