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Anatomical Structure🐕 Dogs🐈 Catsmusculoskeletal

Stifle Joint (Knee)

🗣️ Pronounced:STY-ful JOYNT
In One Sentence (Plain English)

The complex synovial joint connecting the femur, tibia, and patella, equivalent to the human knee joint.

Editorial Status: Verified from peer-reviewed veterinary sources (v1.0)
Updated: 2026-01-15

💬 In Plain English

The stifle is the veterinary anatomical name for your pet’s knee. It is the large hinge joint located on the rear leg between the thigh bone (femur) and the shin bone (tibia). It contains the kneecap (patella), two shock-absorbing cartilage crescents (menisci), and two crossing internal ligaments (the cranial and caudal cruciate ligaments). Because dogs walk with their stifles permanently bent at a forward-sloping angle, immense force is constantly concentrated across this joint, making it the most frequently injured joint in dogs.

🔬 Clinical & Technical Depth

For Vets & Technicians

Formal Clinical Definition

Compound condylar synovial joint comprising the femorotibial joint and the femoropatellar joint. Stabilized by cranial and caudal cruciate ligaments, medial and lateral collateral ligaments, and the patellar tendon.

Why Veterinarians Use It

Veterinarians palpate the stifle joint during orthopedic exams to check for cranial cruciate tears, patellar luxation, joint effusion, and osteoarthritis crepitus.

Clinical Context Encountered

Discussed whenever a dog is limping on a hind leg, holding a rear leg up, or diagnosed with a torn ACL/CCL.

Clinical Reference Guide (Anatomical Structure)

Anatomical Location

Mid-region of the hind limb, joining the distal femur, proximal tibia, and patella.

Normal Physiological Function

Hinge-like flexion and extension of the pelvic limb with slight internal rotation during flexion, supporting weight-bearing propulsion.

🐕 vs 🐈 Species Differences

Dogs walk with their stifle in a permanent state of partial flexion (roughly 135° angle), which generates continuous cranial shear force along the sloping tibial plateau during weight bearing.

🚨 Red Flag Warnings (When to Contact an Emergency Vet)
  • •Sudden severe non-weight-bearing lameness on a hind leg usually indicates acute cranial cruciate ligament rupture or patellar lockup requiring orthopedic examination.

❓ Questions to Ask Your Veterinarian

Take these actionable questions with you to your next clinic visit or appointment:

  • 1Is there swelling (effusion) or thickening (medial buttress) felt inside the stifle joint?
  • 2Does the patella (kneecap) stay securely in its groove, or does it pop out (luxating patella)?

Academic & Clinical References