I would get a second opinion. In humans, if a cervical disk ruptures and pinches the nerves, the options are to wait and see, or do surgery (pretty much the same surgery you are contemplating). Many people recover fully without surgery, though it often takes several months before any weakness fully recovers. If the fusion fully heals, the dog should be pretty fuctional, though really rough play is probably not a good idea, but running, walks, swimming etc should be fine. Whether or not surgery is indicated depends on pain, neurologic dysfunction, and the anatomy of the involved disk. If the spinal cord is in danger, surgery is usually indicated. If the spinal cord is involved, the dog would have back leg weakness as well as front leg weakness, and bowel/bladder dysfunction.

The other option that worked very well for me (herniated disk, myself) was accupuncture. It helped tremendously with the pain, not so sure it helped the weakness as that took quite a bit longer, but it takes the nerves time to heal.

Good luck!

Jake's mom