Which joint is primarily affected by a rupture of the cranial cruciate ligament?

Which joint is primarily affected by a rupture of the cranial cruciate ligament?

• A. Hip joint
• B. Stifle joint
• C. Elbow joint
• D. Shoulder joint

Answer: (B)

The cranial cruciate ligament sits inside the knee joint (the stifle in quadrupeds) and prevents the tibia from sliding forward under the femur when the leg bears weight. If it ruptures, the knee becomes unstable, especially during weight-bearing, leading to tibial thrust and lameness. This injury is specific to the stifle; the hip, elbow, and shoulder joints aren’t primarily involved because their stability depends on ligaments and structures within those joints, not the cruciate ligaments inside the knee. So the stifle joint is the one primarily affected.

The cranial cruciate ligament sits inside the knee joint (the stifle in quadrupeds) and prevents the tibia from sliding forward under the femur when the leg bears weight. If it ruptures, the knee becomes unstable, especially during weight-bearing, leading to tibial thrust and lameness. This injury is specific to the stifle; the hip, elbow, and shoulder joints aren’t primarily involved because their stability depends on ligaments and structures within those joints, not the cruciate ligaments inside the knee. So the stifle joint is the one primarily affected.