Knee Anatomy

Knee Joint• The most poorly constructed joint in

the body. Femur has rounded distal epiphysis while proximal epiphysis of Tibia is flat. Creates a very unstable design.

• Comprised of four separate bones.– Femur– Tibia– Fibula– Patella

Femur and Tibia• Articular cartilage

covers the ends of both the femur and the tibia.

• Medial and Lateral Condyles- found at the distal end of the Femur.

• Medial and lateral Condyles found at the proximal end of the Tibia.

Patella

• Patella tendon- attaches onto the anterior of the Tibia.

• Provides protection of Knee Joint, Patella also lifts tendons to increase leverage.

• Quadriceps tendon-attaches the Quadriceps to the patella.

Cruciate Ligaments• Major stabilizing

ligaments in the knee.• Anterior Cruciate

Ligament (ACL)-prevents the tibia from sliding out in front of the femur.

• Posterior Cruciate Ligament (PCL) prevents knee from hyperextending

• Injuries are most often caused by hyperflexion and hyperextension of the knee or rotation at the knee.

Cruciate Ligaments• Posterior Cruciate

Ligament (PCL)-It prevents the tibia from sliding backwards under the femur.

• Injuries usually caused by Hyperextension

• These cruciate ligaments get their name for their cross over (crucifix) arrangement.

Collateral Ligament• Medial Collateral

Ligament (MCL)- connect the tibia and the femur on the medial side of the knee joint.

• A force from the lateral side could cause a tear to MCL.

• Very common injury in many contact sports.

Collateral Ligament

• Lateral Collateral Ligament (LCL)- connect the fibula to the femur on the lateral side of knee.

• A force from the medial side (rare) can cause a tear of the LCL.

Cartilage

• Articulate Cartilage-covers the moving parts of the knee.

• Very smooth and slippery.

• Chronic damage to articulate cartilage leads to osteoarthritis.

Cartilage • Meniscus- half moon shaped cartilage (Fibrocartilage) lying between the knee joint.

• These Menisces (Lateral/Medial) act as shock absorbers to handle pounding in the joint.

• Often prone to tearing, which may require surgery to remove fragment.

Meniscus Tear

Knee Injuries• ACL Replacement surgery.• Often requires harvesting

1/3rd of Patellar tendon or from cadaver.

• Animation• Animation 2

KNEE SURGERYArthroscopic Surgery for Torn Meniscus

http://www.youtube.com/watch?v=pguNCtOwzEc

http://www.youtube.com/watch?v=i8EpT3uCVWU

Checkout Animation on Arthroscopic Surgery