What causes hip pain radiating into the groin when walking or sitting?

Hip Pain Radiating to Groin: Differential Diagnosis and Evaluation

Hip pain radiating into the groin when walking or sitting is most commonly caused by intra-articular hip pathology, particularly femoroacetabular impingement (FAI) syndrome, acetabular labral tears, or hip osteoarthritis in older adults, though extra-articular causes like iliopsoas tendinopathy and referred pain from the lumbar spine must be systematically excluded. 1, 2

Immediate Red Flags to Exclude First

Before considering common causes, you must rule out serious pathology that requires urgent intervention:

• Stress fractures (femoral neck or pubic ramus): insidious onset, night pain, inability to bear weight, focal bone tenderness 2
• Tumors: night pain, constitutional symptoms, progressive worsening 2
• Septic arthritis/osteomyelitis: acute onset, fever, inability to bear weight, severe rest pain 2
• Slipped capital femoral epiphysis (SCFE): relevant in adolescents/young adults, presents as medial thigh or knee pain with external rotation deformity 2, 3

Primary Causes of Hip-to-Groin Pain

Intra-Articular Hip Pathology

Femoroacetabular Impingement (FAI) Syndrome is the leading cause in young to middle-aged active adults:

• Groin pain worsened by hip flexion, adduction, and internal rotation 1, 2
• Positive FADIR (flexion-adduction-internal rotation) test, though a negative test helps rule out hip-related pain 1
• Cam or pincer morphology visible on radiographs 2

Acetabular Labral Tears frequently coexist with FAI or dysplasia:

• Sharp, catching pain in groin/medial hip with mechanical symptoms (clicking, locking) 2
• Often requires MRI or MR arthrography for definitive diagnosis 1, 2

Hip Osteoarthritis is the predominant cause in older adults:

• Medial groin and thigh aching discomfort, worse with activity, relieved by rest 2
• Pain on internal rotation with limited range of motion 2
• Physical examination and radiography may be sufficient without MRI 1

Acetabular Dysplasia/Hip Instability:

• Medial groin pain with sensation of instability 2
• Misalignment between femoral head and acetabulum on imaging 2
• Apprehension with provocative maneuvers 2

Extra-Articular Causes

Iliopsoas Tendinopathy presents with:

• Anterior/medial groin pain 1, 2
• Pain with resisted hip flexion 2
• May cause internal snapping (coxa saltans) 1, 4

Lumbar Spine Pathology is a critical competing diagnosis:

• Sharp lancinating pain referred to medial thigh 2
• Induced or worsened by sitting, standing, or walking 2
• Must be screened in all hip pain evaluations 1, 2

Sacroiliac Joint Dysfunction:

• Refers pain to groin/medial hip 2
• Tenderness over SI joint with positive provocative tests 2

Diagnostic Algorithm

Step 1: Clinical Assessment

• Determine if pain is activity-related or present at rest 2
• Assess pain location: anterior/groin (intra-articular), lateral (trochanteric), or posterior (referred) 5, 6
• Identify aggravating positions: sitting and walking suggest intra-articular or referred spine pathology 2

Step 2: Physical Examination

Essential maneuvers:

• FADIR test: most useful for intra-articular pathology 1, 2
• Hip range of motion: particularly internal rotation (limited in osteoarthritis) 2
• Mandatory lumbar spine screening in all cases to exclude referred pain 1, 2
• Resisted hip flexion to assess iliopsoas involvement 2

Step 3: Imaging Protocol

First-line imaging:

• AP pelvis and lateral femoral head-neck radiographs should be obtained first in most cases 1, 2
• Radiographs may be sufficient for osteoarthritis diagnosis 1
• Specialized views (false profile, Dunn view) can evaluate dysplasia or FAI 1

Advanced imaging when radiographs are negative, equivocal, or nondiagnostic:

• MRI hip without contrast is the next appropriate study for suspected intra-articular pathology 1, 2
• MRI is highly sensitive and specific for labral tears, cartilage damage, and soft tissue abnormalities 1
• MR arthrography is the diagnostic test of choice for labral tears when surgery is being considered 2, 6
• Ultrasound can evaluate iliopsoas tendinopathy, bursitis, and guide diagnostic injections 1, 2

Diagnostic injections:

• Ultrasound-guided anesthetic injection into the hip joint can differentiate intra-articular from extra-articular sources 5, 4
• Iliopsoas bursa injection helps distinguish tendinopathy from joint pathology 4

Critical Clinical Pitfalls

Coexisting pathology is common:

• Labral tears frequently coexist with FAI or dysplasia 2
• Multiple pain generators may be present simultaneously 1, 4

Referred pain patterns:

• Hip pathology can present as knee pain 1, 2
• Spine pathology commonly presents as hip/groin pain 1, 2
• Intra-abdominal and pelvic pathology can refer to the groin 5

Imaging interpretation requires clinical correlation:

• Incidental findings are common in asymptomatic individuals 2
• Cam and pincer morphology may be present without symptoms 1
• Never diagnose based on imaging alone without matching clinical findings 1, 2

Age-specific considerations:

• SCFE must be considered in adolescents and young adults with hip/groin pain 2, 3
• Osteoarthritis becomes increasingly likely in middle-aged and older adults 7, 5