Where is iliopsoas (muscle in the lower back) pain typically located after hip replacement surgery?

Iliopsoas Pain After Hip Replacement: Location and Management

Iliopsoas pain after hip arthroplasty typically presents as groin pain that radiates ventromedially along the leg and is exacerbated by hip flexion activities such as climbing stairs or rising from a seated position. 1, 2, 3, 4

Pain Location and Clinical Presentation

• Primary location: Anterior groin region
• Radiation pattern: Ventromedial aspect of the thigh
• Pain triggers:
  • Hip flexion activities (especially forced or resisted)
  • Ascending stairs
  • Rising from seated position
  • Hyperextension of the hip

Diagnostic Approach

Imaging

1. Radiographs should be the first imaging test to evaluate:

   • Acetabular component position and prominence (especially on lateral views)
   • Component loosening or malposition 5

2. MRI without contrast is recommended when radiographs are negative or equivocal:

   • Can detect iliopsoas tendinopathy
   • May identify fluid collections or cysts near the iliopsoas 5, 6

3. Bone SPECT/CT can be useful when other imaging is inconclusive:

   • Can identify iliopsoas tendinopathy that may be missed on other imaging modalities 5

Diagnostic Confirmation

• Fluoroscopy-guided iliopsoas tendon sheath injection with local anesthetic:
  • Pain relief after injection confirms the diagnosis
  • Serves both diagnostic and therapeutic purposes 3

Management Algorithm

1. Conservative Management (First-line)

• Success rate: Approximately 50% of patients achieve pain resolution 1
• Interventions:
  • Physical therapy focusing on iliopsoas stretching
  • Anti-inflammatory medications
  • Activity modification
  • Corticosteroid injection into the iliopsoas tendon sheath (ultrasound or fluoroscopy-guided) 6, 1

2. Surgical Management (For persistent symptoms after 3-6 months of conservative treatment)

Decision based on acetabular component prominence:

• <8 mm acetabular component prominence:

  • Recommended procedure: Iliopsoas tenotomy
  • Success rate: 100% pain resolution in appropriate candidates
  • Mean Harris Hip Score post-procedure: 89 points 1

• ≥8 mm acetabular component prominence:

  • Recommended procedure: Acetabular component revision
  • Success rate: 92% pain resolution
  • Tenotomy success rate in this group: Only 33% 1

Outcomes and Prognosis

• Overall surgical success rate: 76-82% pain resolution 1, 7
• Iliopsoas tenotomy provides comparable functional outcomes to acetabular revision with fewer complications 7
• Younger patients and those with previous spine fusion have higher risk of developing iliopsoas tendinopathy after hip replacement 3

Common Pitfalls

• Iliopsoas impingement is often underdiagnosed as a cause of persistent groin pain after hip replacement 2, 4
• Patients with iliopsoas tendinopathy may also report low back pain and greater trochanteric pain, which can confuse the diagnosis 3
• In patients with metal-on-metal hip implants, extracapsular disease associated with adverse reactions to metal debris could be misinterpreted as iliopsoas tendinopathy 6
• Iliopsoas cysts can develop and cause similar symptoms, requiring specific identification and management 2

By understanding the typical location and presentation of iliopsoas pain after hip replacement, clinicians can provide targeted diagnostic workup and effective management to improve outcomes and quality of life for these patients.