The posterior arch of C1 is removed together with the epidural tumor.
The intervening ligamentum flavum is excised.
Based on preoperative planning, the amount of posterior arch to be removed to achieve enough decompression can be determined beforehand.
The nerve root should be decompressed as well in order to avoid occipital neuralgia.
The spinal cord, dura and tumor should otherwise be manipulated as little as possible.