What is the recommended work‑up for hip pain?

Work-up for Hip Pain

Begin with anteroposterior (AP) pelvis and lateral femoral head-neck radiographs as the initial imaging study for all patients presenting with hip pain. 1, 2

Initial Clinical Assessment

Physical Examination

• Perform the FADIR (flexion-adduction-internal rotation) test – a negative test helps rule out hip disease in young and middle-aged active adults 2
• Assess pain location (anterior, lateral, or posterior) to guide differential diagnosis 3
• Screen for non-hip sources: lumbar spine pathology, intra-abdominal/pelvic causes, and other musculoskeletal conditions must be excluded 2, 4

Critical Caveat

Never make a diagnosis based on imaging alone – imaging must always be combined with clinical symptoms and physical examination findings 2

Imaging Algorithm

Step 1: Plain Radiographs (First-Line)

• AP pelvis view 1, 2
• Lateral femoral head-neck view (Dunn, frog-leg/Lauenstein, or cross-table view) 2
• These provide essential information about bony morphology and help identify fractures, dislocations, and structural abnormalities 1

Step 2: Advanced Imaging Based on Clinical Scenario

For Suspected Fracture with Negative/Indeterminate Radiographs:

• Non-contrast CT is the first-line advanced study 1
• If CT remains negative or equivocal but clinical suspicion persists, proceed to non-contrast MRI 1

For Suspected Soft Tissue Injury (Tendon, Muscle, Ligament):

• MRI without contrast is the preferred modality after negative or indeterminate radiographs 1
• MRI detects 100% of proximal hamstring avulsions versus only 58.3% for ultrasound 1
• Ultrasound has insufficient evidence for acute tendon/muscle/ligament evaluation and should not be used as the next imaging study 1

For Intra-articular Pathology Assessment:

• MRI/MRA (magnetic resonance arthrogram) or CT arthrogram when evaluating labrum, cartilage, or ligamentum teres 2
• Use when three-dimensional morphological assessment is indicated 2
• Important caveat: Labral, chondral, and ligamentum teres findings are common in asymptomatic individuals and should be interpreted with clinical correlation 2

For Post-Reduction Hip Dislocation:

• Repeat AP and lateral radiographs to confirm successful relocation 1
• Non-contrast CT if large posterior acetabular wall fracture present or difficulty achieving reduction 1

For Fracture Characterization Pre-Surgery:

• Non-contrast CT when further characterization of fracture alignment is needed for surgical planning 1
• Non-contrast MRI may be appropriate to identify incomplete intertrochanteric fracture extension 1

Diagnostic Categories After Imaging

Hip-related pain can be categorized into three main conditions 2:

1. Femoroacetabular impingement (FAI) syndrome
2. Acetabular dysplasia and/or hip instability
3. Other conditions including soft-tissue pathology (labrum, cartilage, ligamentum teres) without specific bony morphology

Key Pitfalls to Avoid

• Do not rely on ultrasound for acute tendon/muscle injuries – MRI is far superior with 100% vs 58.3% detection rates for hamstring avulsions 1
• Do not over-interpret incidental imaging findings – many intra-articular abnormalities appear on imaging in asymptomatic individuals 2
• Do not skip plain radiographs – they remain the essential first imaging study regardless of suspected pathology 1, 2
• Do not diagnose based solely on positive imaging – diagnostic imaging has limited ability to confirm a condition as the cause of pain, with only small to moderate post-test probability shifts 2

Special Considerations

For young and middle-aged active adults, consider early referral for conditions with good surgical outcomes including femoroacetabular impingement, labral tears, and gluteus medius tendon tears 3. Standard radiographs combined with thorough history and physical examination are usually sufficient for most hip complaints 5.