Can you explain the surgery for herniated disks in their neck where it had to be fused?

Remove disc: Remove disc, take pressure of nerve and stabilize spine.

Yes: Standard approach for cervical disc surgery is to remove it through the front of neck excavating it from the spinal cord allowing for safe approach & excellent decompression but now you have to stabilize the spine by fusing it. An alternative to a fusion is an artificial disc. Occasionally, disc herniation can be fixed from posterior approach without fusion if it is very lateral or to the side.