Fig. 3From: Ultrasound-guided arthroscopic communication enlargement surgery may be an ideal treatment option for popliteal cysts – indications and techniqueA contrast dye (indigo carmine, broad white arrow) is injected into the popliteal cyst (star) percutaneously using ultrasonography. The 23-gauge needle (narrow white arrow) is clearly visible on the ultrasound screenBack to article page