Left knee MRI of a healthy 21-year-old man. Proton density with fat saturation sequences axial view1. Medial collateral ligament; 2. Great saphenous vein; 3. Sartorius and gracilis muscle; 4. Lateral collateral ligament; 5. Biceps femoris tendon and muscle; 6. Common peroneal nerve. Yellow arrow: PM approach; Green arrow: DP approach; Blue arrow: PL approach. MGN: Gastrocnemius muscle medial head; NVB: Neurovascular bundle; LGN: Gastrocnemius muscle lateral head.