What is the role of x-ray of the cervical or lumbar spine in patients presenting with radicular symptoms?

I agree that X-rays are useless the vast majority of the time.

You can of course pick up lytic lesions from metastasis or plasmacytoma, or other bone-based cancers. Sometimes flexion/extension films are helpful, since MRIs are almost always static and supine (until dynamic MRIs obtain more widespread use). Occasionally MRIs underestimate the issue since the instability is not captured. X-rays can also be helpful for hardware evaluations after surgery.

MRIs are far superior for evaluating the central canal and neuroforamina, as well as associated structures such as muscles, bone, discs, etc, and are the diagnostic tool of choice.

Of course, it should be remembered that there is often poor correlation between the imaging and symptoms. So, do...

I routinely obtain anterior, lateral, and oblique views to gauge the extent of spondylitis. Findings such as spondylolysis, disc space narrowing, and even unsuspected fracture can be identified. Recently, I diagnosed unsuspected concomitant DISH as well as a cause of cervicalgia. Second, insurance companies usually deny MRI without an initial set of X-rays to demonstrate the likely diagnosis of spondylosis as the etiology of radiculopathy.

Insurance companies require X-ray to start authorization for MRI.

One exception would be in trauma patients where there is the need to rule out fracture and instability.