What is the initial workup for a patient with chronic mid-thoracic back pain and a normal x-ray?

Workup for Chronic Mid-Thoracic Back Pain with Normal X-Ray

In adults with chronic thoracic back pain and a normal x-ray, further imaging is generally not indicated unless red flags, myelopathy, or radiculopathy are present. 1

Clinical Assessment Priority

The critical first step is determining whether red flags or neurologic symptoms exist, as this fundamentally changes the workup approach:

Screen for Red Flags 2

• Malignancy indicators: History of cancer, unexplained weight loss, age >50, failure to improve with conservative therapy
• Infection signs: Fever, immunosuppression, IV drug use, recent infection
• Fracture risk factors: Age >65, osteoporosis, chronic steroid use, even minor trauma
• Neurologic compromise: Motor/sensory deficits, spasticity, hyperreflexia, positive Babinski sign, bladder dysfunction 2

Imaging Algorithm Based on Clinical Presentation

Without Red Flags or Neurologic Symptoms

No additional imaging is typically warranted. 1 The 2024 ACR Appropriateness Criteria explicitly states that imaging is not typically indicated for chronic thoracic back pain without myelopathy, radiculopathy, or red flags. 1 This mirrors the evidence-based approach used for low back pain, where imaging provides no clinical benefit in uncomplicated cases. 1

Common pitfall to avoid: Over-imaging uncomplicated thoracic back pain provides no clinical benefit, and thoracic disc abnormalities and facet arthropathy are common in asymptomatic individuals, making attribution of pain to imaging findings potentially misleading. 2

With Myelopathy or Radiculopathy

MRI thoracic spine without IV contrast is the appropriate next imaging study. 1 This modality evaluates:

• Compressive etiologies affecting the spinal cord (myelopathy) 1
• Nerve root compression (radiculopathy) 1
• Disc herniations, which are often calcified (20-65%) in the thoracic spine 1
• Spinal stenosis from facet arthropathy or ligamentum flavum ossification 1

With Red Flags Present

For suspected malignancy or infection: MRI thoracic spine without and with IV contrast is the appropriate initial study. 1 This enhanced protocol is superior for:

• Identifying marrow-replacing lesions 1
• Detecting infection and its complications 1
• Assessing small lesions and intradural disease 1

For fracture risk factors (age >65, osteoporosis, chronic steroids, minor trauma): Either thoracic spine radiography, MRI, or CT without IV contrast is appropriate. 1 MRI is particularly useful for:

• Identifying compression fractures even when radiographs are negative 1
• Determining fracture acuity through marrow edema patterns 1

Conservative Management Considerations

Since imaging is not indicated in your scenario (normal x-ray, no red flags implied), the focus should be on therapeutic interventions:

• Thoracic facet joints are pain generators in 34-42% of chronic thoracic pain cases 3, 4
• Therapeutic medial branch blocks show 79-84% of patients achieving significant pain relief at 12 months 3, 4
• Thoracic epidural injections demonstrate 71-80% improvement at 2 years for non-facet joint thoracic pain 5

Key Clinical Nuances

The thoracic spine differs from lumbar and cervical regions in several important ways:

• Symptomatic thoracic disc herniations are rare, accounting for only 1-2% of all discectomies 1
• Thoracic radiculopathy most commonly occurs below T7 2
• The degree of disability from thoracic pain is similar to other spinal regions despite lower prevalence 5

Critical caveat: If the patient's clinical picture changes or they develop new neurologic symptoms, immediate reassessment with MRI is warranted regardless of the normal x-ray. 1