Instead let me discuss in general terms the condition that you are describing. You describe pain the upper neck and numbness that extends throughout your whole body. There are no known tests specific to these symptoms. Neurosurgeons are trained to evaluate such problems and you should seek an evaluation from a board certified specialist in neurosurgery to assist you in your efforts to find an answer. Usually one notices only a small degree of loss of mobility in the neck after anterior cervical discectomy.
Many neurosurgeons do place a bone graft in the space where the disc is removed.
Depending on your age and symptoms, however, this fusion may not be required. My wife lives with chronic pain as a result of a car accident almost two years ago. There was damage to the cyatic and peroneal nerves and we are looking for information on what treatments are available. Nerve injury pain is called neuropathic pain. This pain is difficult to describe, often burning in quality.