What is the appropriate workup for a patient presenting with groin pain?

Workup for Groin Pain

The appropriate workup for groin pain should begin with radiographs of the hip and pelvis, followed by MRI of the hip without contrast if radiographs are negative or inconclusive. 1

Initial Assessment

History

• Onset: Acute vs chronic, traumatic vs non-traumatic
• Location: Groin, lateral hip, buttock, or referred pain
• Quality: Sharp, dull, catching/locking sensation
• Exacerbating/alleviating factors: Worse with activity, better with rest
• Associated symptoms: Fever, weight loss, urinary symptoms

Physical Examination

• Focused tests:
  • Adductor test: Patient supine with hips abducted and flexed at 80°; positive if pain with resistance 2
  • FADIR test (Flexion-Adduction-Internal Rotation): Screens for femoroacetabular impingement (FAI) syndrome 1
  • Palpation of pubic symphysis, adductor origin, iliopsoas
  • Assessment for inguinal hernia

Diagnostic Algorithm

1. Plain Radiographs (First-line)

   • AP pelvis and lateral hip views
   • Rated as "usually appropriate" (9/9) by ACR 1
   • Evaluates for:
     • Osteoarthritis
     • Femoroacetabular impingement morphology
     • Fractures
     • Dysplasia
     • Tumors

2. MRI Hip Without IV Contrast (Second-line)

   • Rated as "usually appropriate" (8/9) by ACR 1
   • Indicated when radiographs are negative or inconclusive
   • Evaluates for:
     • Labral tears
     • Chondral injuries
     • Stress fractures
     • Tendinopathies
     • Muscle strains
     • Osteonecrosis

3. CT Hip Without IV Contrast

   • Rated as "may be appropriate" (5/9) by ACR 1
   • Consider when:
     • MRI is contraindicated
     • Better bony detail is needed (e.g., suspected fracture)
     • Preoperative planning for FAI

4. Ultrasound Hip

   • Rated as "may be appropriate" (4/9) by ACR 1
   • Useful for:
     • Evaluating soft tissue pathology
     • Guiding injections
     • Assessing for hernia

Common Causes and Specific Workup

Hip-Related Pain

• Most common in young and middle-aged active adults 1
• Three main categories:
  1. Femoroacetabular impingement (FAI) syndrome
  2. Acetabular dysplasia/hip instability
  3. Conditions without distinct osseous morphology (labral, chondral, ligamentum teres)

Musculoskeletal Causes

• Adductor strain: MRI pelvis if diagnosis unclear or symptoms persist after conservative management 3
• Osteitis pubis: Radiographs may show sclerosis of pubic symphysis
• Athletic pubalgia ("sports hernia"): MRI pelvis with athletic pubalgia protocol

Non-Musculoskeletal Causes

• Inguinal hernia: Dynamic ultrasonography 3
• Nerve entrapment (ilioinguinal, iliohypogastric, genitofemoral): Consider diagnostic nerve blocks 4
• Intra-abdominal pathology: Consider CT abdomen/pelvis if suspected

Special Considerations

Acute Severe Pain

• Rule out emergent conditions:
  • Testicular torsion: Ultrasound with Doppler 1
  • Septic arthritis: Joint aspiration
  • Fracture: Radiographs, possibly CT or MRI

Chronic Pain

• Consider more extensive workup:
  • MR arthrography: For suspected labral tears when standard MRI is negative
  • Diagnostic injections: Can help localize pain source
  • Laboratory tests: CBC, ESR/CRP if infection or inflammatory condition suspected

Pitfalls to Avoid

1. Failing to recognize hip pathology as a source of groin pain
2. Overlooking non-musculoskeletal causes of groin pain
3. Relying solely on imaging without correlation to clinical findings
4. Missing stress fractures (especially femoral neck) which may not be visible on radiographs
5. Not considering referred pain from lumbar spine or sacroiliac joints

Treatment Considerations

Based on diagnosis:

• Adductor-related pain: Active supervised physical therapy 3
• FAI syndrome: Activity modification, physical therapy; consider surgery if conservative treatment fails
• Hernia: Surgical repair if symptomatic
• Neural causes: Consider nerve blocks or surgical management in refractory cases 4

Remember that groin pain often has multiple coexisting pathologies 5, requiring a thorough systematic approach to diagnosis and management.