What is the next step in the workup for a patient with radicular symptoms of the upper extremities and an x-ray showing left-sided facet (facetal) arthropathy at C4-5?

Next Step in Workup for Upper Extremity Radicular Symptoms with C4-5 Facet Arthropathy

The next step in the workup for a patient with upper extremity radicular symptoms and an X-ray showing left-sided facet arthropathy at C4-5 should be an MRI of the cervical spine to evaluate for nerve root compression and rule out space-occupying lesions. 1

Rationale for MRI as Next Step

MRI is the preferred advanced imaging modality for several important reasons:

1. Evaluation of soft tissue structures: MRI provides superior visualization of:

   • Nerve roots and potential compression
   • Disc herniations
   • Spinal cord compression or signal changes
   • Ligamentous structures
   • Soft tissue inflammation

2. Clinical necessity: For patients with radicular symptoms, the American College of Radiology guidelines emphasize the importance of ruling out space-occupying lesions before proceeding with any interventional treatments 1

3. Diagnostic accuracy: While X-rays can identify bony abnormalities like facet arthropathy, they cannot adequately visualize neural elements or soft tissue pathology that may be causing the radicular symptoms

Important MRI Protocol Considerations

When ordering the MRI, ensure the following:

• Include fluid-sensitive sequences: STIR or T2-weighted fat-saturated sequences are essential for identifying inflammatory changes 2
• Specify "evaluation for cervical radiculopathy" in the order to ensure appropriate protocols are used
• Consider contrast: Gadolinium enhancement may improve visualization of inflammatory changes in discs, facet joints, and entheses, though it is not always required 2

Clinical Context

It's important to recognize that facet arthropathy on X-ray may not be the actual cause of the patient's radicular symptoms:

• Facet joint syndrome typically presents with axial neck pain rather than radicular symptoms 3
• Radicular symptoms more commonly result from disc herniation, foraminal stenosis, or other space-occupying lesions
• Studies have shown poor correlation between imaging findings and clinical symptoms 4, making advanced imaging crucial for accurate diagnosis

Alternative Considerations

If MRI is contraindicated (e.g., pacemaker, certain implants, severe claustrophobia):

1. CT scan: Provides better bone detail but less soft tissue information 1
2. CT myelography: Considered when MRI is contraindicated or for surgical planning 1

Common Pitfalls to Avoid

1. Proceeding directly to interventional procedures: Diagnostic facet blocks or epidural injections should not be performed without first ruling out space-occupying lesions 1

2. Attributing radicular symptoms solely to facet arthropathy: Facet arthropathy on X-ray is common, even in asymptomatic individuals, and may not be the source of radicular pain 4

3. Delaying appropriate imaging: Patients with progressive neurological deficits require prompt imaging evaluation 1

By obtaining an MRI as the next step, you will be able to accurately identify the source of the patient's radicular symptoms and develop an appropriate treatment plan based on specific pathology identified.