Just Received Word From My PA Who Told Me He

Just received word from my PA who told me he wants an MRI done on my back after reviewing my X-ray for a muscle spasm. I was advise that I have arthritis in or around my lumbar region, and a weak spot in my C-spine are. Arthritis I know, however a weak spot in my C-spine I don't. Could you please advise. Respectfully.
Todd