Which knee structure acts as a cartilage disc to absorb shock and cushion the joint?

Which knee structure acts as a cartilage disc to absorb shock and cushion the joint?

• A. Meniscus
• B. ACL
• C. MCL
• D. Patella

Answer: (A)

The main idea is that knee shock absorption comes from the menisci, two fibrocartilaginous discs that sit between the femur and tibia. Their wedge-shaped, cartilage composition lets them compress and spread out the load as you stand, walk, and run. This distribution increases the contact area, converts some of the joint’s compressive force into hoop stresses, and smooths the interaction between the rounded femoral condyles and the relatively flat tibial surfaces. All of this cushions the joint and protects the underlying cartilage from damage during movement. The other structures serve different roles. Ligaments like the ACL and MCL stabilize the joint by guiding and limiting movement, not by acting as cushions between the bones. The patella, or kneecap, is a small bone that protects the front of the knee and improves the mechanical advantage of the quadriceps tendon, rather than serving as the cartilage cushion between femur and tibia.

The main idea is that knee shock absorption comes from the menisci, two fibrocartilaginous discs that sit between the femur and tibia. Their wedge-shaped, cartilage composition lets them compress and spread out the load as you stand, walk, and run. This distribution increases the contact area, converts some of the joint’s compressive force into hoop stresses, and smooths the interaction between the rounded femoral condyles and the relatively flat tibial surfaces. All of this cushions the joint and protects the underlying cartilage from damage during movement.

The other structures serve different roles. Ligaments like the ACL and MCL stabilize the joint by guiding and limiting movement, not by acting as cushions between the bones. The patella, or kneecap, is a small bone that protects the front of the knee and improves the mechanical advantage of the quadriceps tendon, rather than serving as the cartilage cushion between femur and tibia.