What could be the cause of groin pain in a patient?

Groin Pain: Differential Diagnosis and Evaluation

Most Common Causes in Young and Middle-Aged Active Adults

Groin pain most commonly arises from musculoskeletal conditions affecting the hip, adductor muscles, pubic symphysis, abdominal wall, or inguinal region, though urological and intra-abdominal pathology must be systematically excluded. 1, 2

The primary musculoskeletal causes include:

• Hip-related pain (femoroacetabular impingement syndrome, acetabular dysplasia/instability, or labral/chondral lesions without distinct osseous morphology) - these are the most common hip conditions in young and middle-aged active adults presenting with groin pain 1
• Adductor-related groin pain from tendon enthesitis of the adductor longus muscle, particularly common in athletes (6.24% prevalence in soccer players) 3, 2
• Inguinal-related groin pain from posterior abdominal wall weakness ("sportsman's hernia") without a true hernia 2
• Pubic-related groin pain from pubic symphysis pathology or degenerative arthropathy 3, 2
• Iliopsoas-related groin pain from iliopsoas muscle pathology 2

Critical Red Flags Requiring Urgent Evaluation

Immediately exclude urological emergencies and serious pathology before attributing symptoms to musculoskeletal causes:

• Testicular torsion - urological emergency requiring prompt surgical intervention 4
• Renal colic from nephrolithiasis - presents with colicky pain radiating from flank to groin, intensifying with ureteral peristalsis 5, 4
• Epididymitis - infectious/inflammatory process requiring urgent treatment 4
• Stress/insufficiency fractures of the sacrum or pelvis - can radiate hip/groin pain and require cross-sectional imaging when radiographs are negative 1
• Intra-abdominal pathology (appendicitis, abscess) - fever with elevated WBC mandates immediate CT imaging 6

Systematic Physical Examination Approach

Perform targeted physical examination to localize the pain source anatomically: 2

• Adductor testing: Patient supine with hips abducted and flexed at 80 degrees; positive test produces sharp groin pain when patient attempts to adduct legs against resistance 3, 2
• Inguinal palpation: Direct palpation over inguinal canal to assess for hernia or posterior wall weakness 2
• Hip examination: Flexion-adduction-internal rotation (FADIR) test helps rule out hip-related pain when negative, though clinical utility is limited due to poor specificity 1
• Pubic symphysis palpation: Direct tenderness over pubic symphysis suggests pubic-related pathology 2
• Iliopsoas testing: Resisted hip flexion reproduces pain in iliopsoas-related conditions 2

Diagnostic Imaging Algorithm

The choice of imaging depends on clinical suspicion and duration of symptoms:

For Suspected Hip-Related Pain:

• MRI of the hip/pelvis without IV contrast is the primary imaging modality, as clinical examination and plain radiographs have limited diagnostic utility 1
• A comprehensive approach combining history, examination, and imaging is essential because no single test is definitive 1

For Suspected Adductor or Pubic-Related Pain:

• MRI pelvis should be performed if diagnosis is unclear or symptoms persist despite initial conservative management 2
• Plain radiographs have low sensitivity due to overlying soft tissue and are often initially negative 1

For Suspected Inguinal-Related Pain:

• Dynamic ultrasonography should be performed to rule out true hernia and evaluate posterior abdominal wall weakness 2

For Suspected Iliopsoas-Related Pain:

• Hip radiography and MRI are preferred because concomitant hip pathology is often present 2

For Suspected Urological Causes:

• Urinalysis is essential to rule out urinary tract infection 7
• CT abdomen/pelvis WITHOUT contrast is the gold standard for nephrolithiasis with near 100% sensitivity and specificity 5

For Suspected Stress Fractures:

• MRI or CT should supersede bone scintigraphy as first-line cross-sectional imaging when radiographs are negative, as bone scintigraphy lacks specificity and is time-consuming 1
• Cross-sectional imaging for hip fractures should include the sacrum, as sacral stress fractures commonly radiate hip/groin pain 1

Initial Management Based on Etiology

Musculoskeletal Causes:

• Active, supervised physical therapy is the initial treatment for adductor-related and pubic-related groin pain 2
• Core strengthening and neuromuscular rehabilitation for inguinal-related groin pain without hernia 2
• Stretching and strengthening program for adductors, abdominal wall, iliopsoas, quadriceps, and hamstrings combined with NSAIDs and muscle relaxants 3
• Gradual return to activity with adequate healing time - precipitate return to sport risks recurrence 8

Surgical Intervention:

• Reserved for cases where conservative management fails after adequate trial 3, 8
• Nerve-related groin pain may require neurolysis or nerve resection with 68% achieving excellent pain relief 9

Common Pitfalls to Avoid

• Do not assume hemorrhoids cause groin pain - hemorrhoids cause anorectal symptoms (bleeding, anal pain, itching) but not groin pain 1
• Do not attribute all groin symptoms to musculoskeletal causes - systematic exclusion of urological emergencies and intra-abdominal pathology is mandatory 2, 4
• Do not rely solely on clinical examination for hip-related pain - examination tests have good sensitivity but poor specificity, requiring imaging confirmation 1
• Do not overlook neural causes - ilioinguinal, iliohypogastric, genitofemoral, and lateral femoral cutaneous nerve entrapment can cause chronic groin pain 9