What is the next step in evaluating hip pain with a negative X-ray result?

Next Evaluation for Hip Pain with Negative X-ray Results

After a negative X-ray for hip pain, MRI without contrast is the recommended next imaging study due to its superior sensitivity (99-100%) for detecting occult fractures and soft tissue pathology. 1

Diagnostic Algorithm Based on Clinical Presentation

Step 1: Determine Pain Location

• Anterior hip/groin pain: Consider intra-articular pathology (labral tears, femoroacetabular impingement, osteoarthritis)
• Lateral hip pain: Consider extra-articular soft tissue abnormalities (greater trochanteric pain syndrome, gluteus medius tendinopathy)
• Posterior hip pain: Consider deep gluteal syndrome, ischiofemoral impingement, or referred pain from lumbar spine 2, 3

Step 2: Select Appropriate Advanced Imaging

Primary Recommendation: MRI Hip Without Contrast

• Highest sensitivity (99-100%) for detecting:
  • Occult fractures
  • Soft tissue injuries
  • Osteonecrosis
  • Tendinopathy
  • Labral tears (though less sensitive than MR arthrography)
  • Bone marrow edema 4, 1

Alternative Options Based on Specific Clinical Suspicion:

• For suspected labral tears or femoroacetabular impingement: MR arthrography (rated 9/9 by ACR) 4
• For extra-articular soft tissue abnormalities (tendinitis, bursitis): Ultrasound (rated 7/9 by ACR) 4
• When MRI is contraindicated: CT without contrast (sensitivity 79-94%, less than MRI) 1

Important Clinical Considerations

Benefits of Early Advanced Imaging

• Prevents delayed diagnosis which can increase:
  • Complications
  • Hospital stays
  • Mortality rates
  • Risk of osteonecrosis 1

Common Pitfalls to Avoid

1. Relying solely on negative X-rays when clinical suspicion remains high
2. Failing to include the pelvis in hip imaging evaluation (38% of patients with negative X-rays have pelvic fractures) 1
3. Using bone scan as next step - not recommended due to insufficient evidence 1
4. Delaying MRI when symptoms persist despite negative X-rays
5. Missing extra-articular causes of hip pain by focusing only on the joint 3

Special Considerations

• If CT is performed and negative but clinical suspicion remains high, proceed to MRI 1
• Ultrasound-guided anesthetic injections can help differentiate intra-articular from extra-articular causes of pain 2
• For suspected tumors or tumor-like lesions, MRI provides essential information for diagnosis and staging 5

By following this evidence-based approach to evaluating hip pain with negative X-rays, clinicians can ensure timely diagnosis and appropriate treatment, reducing morbidity and improving patient outcomes.