What are the next steps for managing ongoing left hip pain with numbness when an x-ray shows no dislocation, fracture, or soft tissue abnormalities?

Management of Ongoing Left Hip Pain with Numbness and Normal X-rays

MRI of the hip without IV contrast is the next appropriate imaging study for ongoing hip pain with numbness when radiographs are negative. 1

Immediate Next Steps

Advanced Imaging Selection

MRI hip without IV contrast (rated 9/9 "usually appropriate") should be obtained as the primary next diagnostic test. 1 This modality is highly sensitive and specific for detecting:

• Soft tissue abnormalities including tendonitis, bursitis, muscle/tendon tears, and nerve compression that could explain the numbness 1, 2
• Occult fractures not visible on plain radiographs, particularly stress fractures or basicervical femoral neck fractures 1, 3
• Avascular necrosis of the femoral head, which appears as well-defined modifications with characteristic low signal intensity lines 4
• Labral tears (though MR arthrography is superior if this is specifically suspected) 1
• Bone marrow edema suggesting early pathology like transient osteoporosis or algodystrophy 4
• Referred pain sources from lumbar spine pathology that may explain the radiating numbness 1, 5

The Numbness Component Requires Special Attention

The presence of numbness suggests potential nerve involvement that warrants specific evaluation:

• Consider lumbar spine imaging if clinical examination suggests radiculopathy or referred pain from spine pathology 5, 2
• Evaluate for deep gluteal syndrome with sciatic nerve entrapment if pain is posterior 2
• Assess for obturator nerve involvement if numbness follows specific dermatomal patterns 2

Diagnostic Injection Strategy

Image-guided anesthetic injection into the hip joint (rated 8/9 "usually appropriate") can be performed concurrently to determine if pain originates from the hip joint itself versus surrounding structures or referred sources. 1, 5 This is particularly valuable when:

• Multiple pain sources are suspected (hip, spine, pelvis) 1, 5
• MRI findings are equivocal 1
• Therapeutic benefit is desired alongside diagnostic information 5

Alternative Imaging Considerations

Ultrasound (rated 7/9 "may be appropriate") can be used as an adjunct for:

• Evaluating specific soft tissue structures like trochanteric bursitis or iliopsoas tendinopathy 1
• Guiding diagnostic/therapeutic injections 1
• Real-time dynamic assessment of snapping hip syndrome 1

However, ultrasound is inferior to MRI for comprehensive evaluation of intra-articular pathology and occult fractures. 1, 3

What NOT to Do

Nuclear medicine bone scan, PET imaging, and CT without contrast are NOT appropriate (all rated 1/9 "usually not appropriate") for this clinical scenario. 1 These modalities:

• Do not adequately evaluate soft tissue pathology causing numbness 1
• Expose patients to unnecessary radiation 1
• Provide less diagnostic information than MRI 1

Critical Pitfalls to Avoid

Do not assume normal radiographs exclude significant pathology. The American Academy of Orthopaedic Surgeons case series demonstrates that occult femoral neck fractures can present with normal initial radiographs, requiring MRI for diagnosis. 1 In one documented case, a patient with normal radiographs and persistent groin pain returned 2 days later, and MRI revealed a mildly displaced basicervical femoral neck fracture. 1

Do not delay MRI if pain worsens or persists beyond 2-3 days, as this may indicate an occult fracture requiring urgent surgical intervention. 1

Do not proceed directly to MR arthrography unless there is specific clinical suspicion for labral tear or femoroacetabular impingement (positive impingement signs on examination). 1 Standard MRI without contrast is the appropriate initial advanced imaging. 1

Clinical Examination Priorities

While obtaining imaging, assess for:

• Location specificity: Anterior/groin pain suggests intra-articular pathology; lateral pain suggests greater trochanteric pain syndrome; posterior pain suggests referred spine pathology or deep gluteal syndrome 2, 3
• Numbness distribution: Dermatomal pattern suggests radiculopathy; non-dermatomal suggests local nerve compression 2
• Range of motion: Pain with internal/external rotation suggests intra-articular pathology 1, 3
• Log-roll test: Loss of external rotation recoil may indicate microinstability 6

Evidence Quality Note

The American College of Radiology Appropriateness Criteria (2017) represent high-quality guideline evidence with systematic review of diagnostic imaging literature, providing the strongest framework for imaging decisions in chronic hip pain. 1 The AAOS Hip Fracture Guidelines (2022) provide complementary evidence specifically highlighting the importance of MRI for occult fractures when radiographs are negative. 1