In a patient with a recent lumbar compression fracture and worsening back pain, would a plain X‑ray be helpful to assess for fracture progression, new fracture, or epidural involvement?

Yes, a plain X-ray is helpful as an initial imaging study in this scenario.

In a patient with a recent lumbar compression fracture and worsening back pain, plain radiography of the lumbar spine is useful as the initial evaluation to assess for fracture progression, new fractures, and spinal alignment 1. However, you should recognize upfront that X-rays have significant limitations and will likely need to be followed by MRI for definitive assessment.

Why X-ray is Helpful

Plain radiographs serve several practical purposes in this clinical scenario:

• Assess fracture progression: Upright anteroposterior and lateral views provide functional information about axial loading and can demonstrate changes in vertebral body height or new collapse 1
• Detect new fractures: Particularly important in patients with osteoporosis or steroid use, where multiple compression fractures are common 1
• Evaluate alignment and stability: Flexion and extension views can assess for abnormal motion or instability 1
• Guide further imaging: Helps determine the specific levels that need detailed evaluation with advanced imaging 2

Critical Limitations You Must Understand

X-rays cannot assess epidural involvement or spinal canal compromise 1. This is a major limitation given your concern about epidural pathology. Additionally:

• X-rays are insensitive for determining fracture acuity—they cannot reliably distinguish between acute and chronic fractures (sensitivity only 52% compared to MRI) 3
• Evaluation of vertebral body comminution is limited, particularly in osteoporotic patients 1
• At least 50% of bone must be eroded before changes are visible on radiographs 1
• X-rays miss 27% of thoracolumbar fractures that are visible on CT 4

The Algorithmic Approach

Step 1: Order plain lumbar spine radiographs (AP and lateral) immediately as they are:

• Readily available
• Low cost
• Provide baseline structural information 1

Step 2: Based on X-ray findings, proceed as follows:

If X-rays show new or progressive collapse, or any concerning features → proceed directly to MRI lumbar spine without IV contrast 1

If X-rays are normal or unchanged but pain is worsening → still obtain MRI lumbar spine without IV contrast because:

• Bone marrow edema indicating acute fracture is only visible on MRI 1
• Spinal canal compromise from retropulsed fragments requires MRI 1
• Epidural involvement cannot be assessed without MRI 1

Step 3: Consider adding IV contrast to the MRI if there is clinical suspicion of:

• Underlying malignancy (to distinguish pathologic from osteoporotic fracture) 1
• Infection (epidural abscess) 1
• Inflammation 1

Why MRI is Ultimately Necessary

MRI without IV contrast is the definitive study for your clinical concerns 1. It provides:

• Fracture acuity determination: Bone marrow edema confirms acute fracture 1
• Spinal canal assessment: Demonstrates any compromise from displaced or retropulsed fracture fragments 1
• Epidural evaluation: Can identify epidural hematoma or other epidural pathology 1
• Differentiation of benign vs. malignant: Convex posterior vertebral body border, extension into posterior elements, and abnormal marrow signal suggest pathologic fracture 1

Common Pitfalls to Avoid

1. Don't rely solely on X-rays to rule out progression or complications—normal X-rays do not exclude acute fracture or epidural involvement 3, 5

2. Don't delay MRI if there are any red flags: neurologic symptoms, severe or progressive pain, history of malignancy, fever, or immunosuppression warrant immediate MRI 1, 2

3. Don't order CT as the next step unless MRI is contraindicated—while CT provides excellent bony detail and can detect fractures missed on X-ray 1, it is inferior to MRI for assessing fracture acuity, marrow pathology, and epidural involvement 1

4. Don't assume radiographic findings correlate with symptoms—studies show that X-ray findings often do not correlate with clinical presentation in primary care settings 6

Bottom Line

Start with plain X-rays for practical reasons, but plan for MRI as the definitive study. The X-ray provides quick, accessible structural information and may reveal obvious progression, but worsening pain in a patient with a recent compression fracture warrants MRI evaluation regardless of X-ray findings to assess for fracture acuity, canal compromise, and epidural pathology that X-rays simply cannot detect 1.