A 47-year-old male patient with posterior ankle pain on the right side. Sometimes a snap and there locking occurs. Rotational movements are painful. During physical examination there is a recognizable pain over the posterior ankle joint and the posterior impingement test is positive.

Picture 1 & 2: MRI shows a ganglion cyst (red encircled).

Picture 3: During posterior arthroscopy the ganglion cyst (red) was identified and resected.

Picture 4: Endoscopic view after removal of the ganglion cyst: flexor hallucis longus (1), talus (2), subtalar joint (3), intermalleolar ligament (4).

Picture 5: Endoscopic view after removal of the intermalleolar ligament.