The knee

Question 1

Bones of the Knee

Answer 1

1. Femur: The thigh bone, which has two condyles (medial and lateral) that articulate with the tibia.
2. Tibia: The shin bone, which has medial and lateral condyles that receive the femoral condyles.
3. Fibula: Although not directly involved in the knee joint, it is situated laterally and provides muscle attachment points.
4. Patella: Also known as the kneecap, it sits in front of the knee joint and protects it, while also improving the leverage of the quadriceps muscle.

Question 2

Joints of the Knee

Answer 2

The knee joint is classified as a hinge joint (trochoginglymus), allowing primarily flexion and extension, with some degree of rotation when the knee is flexed. It consists of:
- Patellofemoral Joint: The articulation between the patella and the femur.
- Tibiofemoral Joint: The main joint between the femur and tibia, allowing for flexion and extension.

Question 3

Ligaments of the Knee

Answer 3

The stability of the knee joint is maintained by several ligaments:
1. Extrinsic Ligaments:
- Medial Collateral Ligament (MCL): Stabilizes the inner side of the knee.
- Lateral Collateral Ligament (LCL): Stabilizes the outer side of the knee.
- Patellar Ligament: Connects the patella to the tibia, helping to stabilize the knee.

2. Intrinsic Ligaments:
   - Anterior Cruciate Ligament (ACL): Prevents forward movement of the tibia relative to the femur.
   - Posterior Cruciate Ligament (PCL): Prevents backward movement of the tibia relative to the femur.
   - Transverse Ligament: Connects the two menisci anteriorly

Question 4

Muscles of the Knee

Answer 4

The muscles surrounding the knee joint are crucial for its movement:
1. Quadriceps Femoris: The primary extensor of the knee, located in the anterior thigh.
- Composed of four muscles: rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius.

2. Hamstrings: The primary flexors of the knee, located in the posterior thigh.
   - Composed of three muscles: biceps femoris, semitendinosus, and semimembranosus.
3. Gastrocnemius: A calf muscle that also assists in knee flexion

Question 5

Blood Vessels of the Knee

Answer 5

The blood supply to the knee is primarily through branches of the femoral artery:
1. Popliteal Artery: A continuation of the femoral artery that branches into:
- Anterior Tibial Artery: Supplies the anterior compartment of the leg.
- Posterior Tibial Artery: Supplies the posterior compartment of the leg.
- Fibular Artery: Supplies the lateral compartment of the leg.

2. Genicular Arteries: Branches of the popliteal artery that supply the knee joint

Question 6

Nerves of the Knee

Answer 6

The knee joint is innervated by several nerves:
1. Femoral Nerve: Supplies the quadriceps and provides sensory innervation to the anterior thigh and medial leg via the saphenous nerve.
2. Sciatic Nerve: Gives rise to the tibial nerve and common peroneal nerve, which innervate the muscles of the posterior thigh and lower leg.
3. Obturator Nerve: Supplies the adductor muscles of the thigh.
4. Sural Nerve: Provides sensory innervation to the posterior aspect of the leg.