What could be causing deep pelvic pain on the right side, exacerbated by hip flexion, with point tenderness and weakness?

Deep Right Pelvic Pain with Hip Flexion Aggravation: Diagnostic Approach

Begin with plain radiographs of the pelvis and right hip, followed by MRI if radiographs are negative or nondiagnostic, as this presentation most likely represents iliopsoas pathology (bursitis, tendinosis, or muscle strain) or hip joint pathology requiring soft tissue evaluation. 1

Initial Imaging Strategy

• Obtain plain radiographs first (pelvis and proximal femur views) to screen for osseous abnormalities, arthritis, fractures, or tumors that could explain the symptoms 1
• Radiographs serve as an excellent screening tool and guide selection of additional imaging, even when normal 1
• Pain with hip flexion and difficulty donning pants strongly suggests iliopsoas involvement or anterior hip pathology 1

When Radiographs Are Negative or Nondiagnostic

Proceed directly to MRI without contrast as the next step, which is both highly sensitive and specific for detecting soft tissue abnormalities around the hip and pelvis 1

MRI Will Identify:

• Iliopsoas bursitis or tendinosis - the most likely diagnosis given pain with hip flexion and point tenderness 1
• Subiliacus bursitis 1
• Athletic pubalgia 1
• Abductor tendinosis or tears 1
• Hamstring injuries 1
• Labral tears (though these typically present with mechanical symptoms) 1
• Occult fractures or stress injuries 1
• Soft tissue masses or tumors 1

Alternative: Ultrasound

• Consider ultrasound if MRI is unavailable or for targeted evaluation of suspected iliopsoas pathology 1
• Ultrasound can evaluate soft tissues but is operator-dependent and less comprehensive than MRI 1
• Useful for guiding diagnostic/therapeutic injections once a diagnosis is suspected 1

Critical Differential Diagnoses to Consider

Musculoskeletal (Most Likely):

• Iliopsoas bursitis/tendinosis - classic presentation with hip flexion pain and anterior/medial hip tenderness 1
• Hip joint pathology (labral tear, early arthritis, femoroacetabular impingement) 1
• Abductor tendon pathology 1
• Pelvic floor myofascial pain with referred symptoms 1, 2

Intra-pelvic (Less Likely Without Additional Symptoms):

• Pelvic congestion syndrome - would typically show engorged pelvic veins on Doppler ultrasound 1
• Adhesive disease - difficult to diagnose nonoperatively and causality with pain is unclear 1
• Chronic inflammatory disease or hydrosalpinx - would show specific findings on ultrasound 1

Urological:

• Interstitial cystitis/bladder pain syndrome - but typically presents with urinary frequency/urgency, not isolated hip flexion pain 1, 3

Physical Examination Findings to Document

• Exact location of point tenderness - anterior groin suggests iliopsoas, lateral suggests abductor pathology 1
• Hip range of motion, particularly internal rotation (reproduces pain in intra-articular pathology) 1
• FABER test (Flexion, ABduction, External Rotation) - positive suggests hip joint pathology 1
• Resisted hip flexion - reproduces pain in iliopsoas pathology 1
• Pelvic floor tenderness on examination - suggests myofascial component 1, 2
• Gait pattern and need for assistive device 1

Common Pitfalls to Avoid

• Do not skip radiographs - they are essential screening and may reveal unexpected findings like tumors or fractures 1
• Do not assume gynecologic origin without specific gynecologic symptoms - 80% of chronic pelvic pain is non-gynecologic 2
• Do not order CT for this presentation - it is less sensitive for soft tissue evaluation than MRI 1
• Avoid premature diagnostic injections until imaging localizes the pathology 1
• Do not overlook referred pain from the lumbar spine, though hip flexion aggravation makes this less likely 1

Treatment Considerations After Diagnosis

If Iliopsoas Pathology Confirmed:

• Manual physical therapy targeting pelvic floor and hip musculature if myofascial component present 1
• NSAIDs when not contraindicated 1
• Avoid pelvic floor strengthening exercises (Kegels) if pelvic floor hypertonicity present 1
• Consider ultrasound-guided diagnostic/therapeutic injection for confirmation and temporary relief 1

If Hip Joint Pathology:

• Physical therapy for mild-to-moderate disease 1
• NSAIDs and acetaminophen for symptom management 1
• Surgical consultation if conservative measures fail 1

The key distinguishing feature is that pain with hip flexion and difficulty with functional activities like dressing points strongly toward iliopsoas or anterior hip pathology rather than deep pelvic visceral causes, making musculoskeletal imaging the priority. 1