How should I evaluate and manage a patient presenting with right groin pain?

Evaluation and Management of Right Groin Pain

Initial Diagnostic Approach

Begin with plain radiographs (AP pelvis and lateral hip) as your essential first-line imaging study, as they identify hip osteoarthritis, fractures, and other bony pathology that commonly cause groin pain. 1

Critical Physical Examination Maneuvers

• Hip internal rotation test: Pain with internal rotation of the hip strongly suggests intra-articular hip pathology such as osteoarthritis, labral tears, or femoral neck fractures 1
• Adductor squeeze test: With the patient supine, hips abducted and flexed at 80 degrees, resistance against adduction that reproduces sharp groin pain indicates adductor-related pathology 2, 3
• Gait assessment: Antalgic gait with assistive device use suggests significant hip pathology requiring urgent evaluation 1
• Direct palpation: Systematically palpate for adductor, pubic, inguinal, and iliopsoas tenderness to narrow the differential 3

When to Obtain CT Abdomen and Pelvis

Order CT abdomen and pelvis if the clinical presentation suggests non-musculoskeletal pathology (fever, nausea, vomiting, abdominal tenderness beyond the groin), as it has 95% sensitivity and 94% specificity for appendicitis and identifies alternative diagnoses in 23-45% of cases 4, 5. CT frequently alters management, with 41% of patients hospitalized and 22% requiring surgical or image-guided intervention when non-appendiceal diagnoses are found 4.

Advanced Imaging Algorithm

• MRI of the hip: Obtain when initial radiographs are negative but clinical suspicion for hip pathology remains high, particularly for occult fractures, labral tears, or early avascular necrosis 1, 3
• MRI of the pelvis: Perform if adductor-related groin pain diagnosis is unclear or symptoms have not improved after 6-8 weeks of conservative management 3
• Dynamic ultrasonography: Use specifically for inguinal-related groin pain to rule out true hernia and evaluate posterior abdominal wall weakness 3

Essential Laboratory Testing

• Pregnancy test: Mandatory for all women of reproductive age before any imaging or treatment 1
• Complete blood count and inflammatory markers (ESR, CRP): Only if systemic illness, infection (septic arthritis, osteomyelitis), or inflammatory arthropathy is suspected 1
• Urinalysis: If urinary symptoms are present or nephrolithiasis is suspected 6

Differential Diagnosis by Clinical Pattern

Musculoskeletal Causes (Most Common)

• Hip osteoarthritis (most common in adults >50 years): Groin pain with internal rotation, activity-related pain, radiographic joint space narrowing 1
• Occult hip fracture: Acute onset after fall, pain with weight-bearing, negative initial radiographs mandate MRI within 48-72 hours 1
• Adductor-related groin pain: Positive adductor squeeze test, tenderness over adductor longus insertion, common in athletes 2, 3
• Inguinal-related groin pain ("sports hernia"): Pain with Valsalva, coughing, or sit-ups; may have posterior abdominal wall weakness without true hernia 3, 7
• Iliopsoas-related groin pain: Pain with hip flexion against resistance, often with concomitant hip pathology 3

Non-Musculoskeletal Causes Requiring Urgent Evaluation

• Appendicitis: Fever and leukocytosis are absent in 50% of confirmed cases; clinical assessment alone misclassifies appendicitis in 34-68% of patients 5
• Nephrolithiasis: Colicky pain radiating from flank to groin, intensifies with urination; unenhanced CT has near 100% sensitivity and specificity 6
• Testicular torsion, epididymitis: Urological emergencies requiring prompt action 8
• Inguinal hernia: May present with groin pain without palpable bulge; dynamic ultrasound is diagnostic 3

Treatment Algorithm Based on Diagnosis

Musculoskeletal Groin Pain (Adductor, Pubic, or Inguinal-Related)

Initiate active, supervised physical therapy as first-line treatment, focusing on stretching and strengthening of adductor muscles, abdominal wall muscles, iliopsoas, quadriceps, and hamstrings. 2, 3

• Combine with NSAIDs and muscle relaxants for symptom control 2
• Physical therapy should be gradual and individualized based on pain severity and irritability 2
• If symptoms persist after 3 months of conservative management, consider surgical consultation 3, 7

Inguinal-Related Groin Pain Without Hernia

• Core strengthening and neuromuscular rehabilitation through physical therapy 3
• If conservative management fails after 3 months, herniorrhaphy can return athletes to sport within 3 months 7

Iliopsoas-Related Groin Pain

• Obtain hip radiography and MRI first, as concomitant hip pathology is common 3
• Treatment depends on underlying hip pathology identified

Suspected Appendicitis

• CT confirms appendicitis (appendix >8.2 mm with peri-appendiceal inflammation): Immediate surgical consultation 5
• Borderline CT findings (appendix 7-8 mm without clear inflammation): Admit for 24-hour observation with serial abdominal examinations every 6-12 hours 5
• Negative CT: Safe discharge only if scan is normal, no peritoneal signs, patient tolerates oral intake, with mandatory 24-hour follow-up 5

Suspected Nephrolithiasis

• Unenhanced CT abdomen and pelvis is the gold standard with near 100% sensitivity and specificity 6
• Management depends on stone size and location; urology consultation for stones >5mm or with obstruction 6

Critical Pitfalls to Avoid

• Failing to obtain plain radiographs first: Plain films must precede advanced imaging, as they identify most significant hip pathology and guide further work-up 1
• Missing occult fractures: If radiographs are negative but clinical suspicion remains high (especially post-fall with persistent pain), MRI is mandatory within 48-72 hours 1
• Using absence of fever to exclude appendicitis: Fever is missing in approximately 50% of true appendicitis cases 5
• Relying on normal white blood cell count: Normal WBC has limited diagnostic value with positive likelihood ratio of only 2.47 for appendicitis 5
• Delaying CT beyond 12 hours: When symptoms persist or worsen, delayed imaging increases perforation risk 5
• Neglecting pregnancy testing: Always obtain pregnancy test in women of reproductive age before imaging or treatment 1
• Discharging patients after negative CT without follow-up: Mandatory 24-hour follow-up is required to capture the measurable false-negative rate 5