What diagnostic tests should be ordered for gluteal (gluteus) tendinopathy?

Diagnostic Tests for Gluteal Tendinopathy

MRI without contrast is the preferred diagnostic imaging test for gluteal tendinopathy, offering superior sensitivity and specificity for detecting tendon pathology compared to other modalities. 1

Primary Diagnostic Options

MRI Hip Without IV Contrast

• First-line imaging for suspected gluteal tendinopathy
• Provides excellent visualization of:
  • Tendon defects (partial or complete tears)
  • Tendon avulsions
  • Fatty atrophy of gluteal muscles
  • Peritrochanteric structures (gluteus minimus/medius muscles)
  • Trochanteric bursa 1
• Sensitivity ranges from 33-100% with specificity of 92-100% for detecting gluteal tendon tears 1
• Can distinguish between acute and chronic changes
• Allows assessment of surrounding soft tissue structures

Ultrasound

• Alternative diagnostic option when MRI is contraindicated or unavailable
• Benefits:
  • Can identify tendinopathy, partial tears, and complete tears/avulsion 1
  • Dynamic assessment capability
  • Lower cost than MRI
  • No contraindications related to metal implants
• Limitations:
  • Operator-dependent
  • Lower sensitivity (79%) compared to MRI for gluteal tendon tears 1
  • Difficulty differentiating between trochanteric bursitis and gluteus medius tendinosis 1

Diagnostic Algorithm

1. Initial Assessment: Plain radiographs of the hip to rule out bony abnormalities
2. Primary Diagnostic Test: MRI without contrast of the hip
3. Alternative: Ultrasound if MRI is contraindicated or unavailable

Clinical Diagnostic Tests

When imaging is not immediately available, certain clinical tests can help diagnose gluteal tendinopathy:

• Single-leg standing test: Pain reported within 30 seconds of standing on the affected limb has 100% specificity for MRI-confirmed gluteal tendinopathy 2
• Palpation: Tenderness over the greater trochanter has 80% sensitivity 2
• Provocative tests: Combination of compressive and tensile loading tests provides best diagnostic utility

Important Considerations

• Both trochanteric bursitis and gluteal tendinopathy may coexist, making clinical differentiation difficult 1
• Approximately 31% of patients with MRI-confirmed gluteal tendinopathy may have negative clinical tests 2
• Early diagnosis and appropriate management can prevent progression to chronic pain and disability
• In post-arthroplasty patients, metal artifact reduction sequence (MARS) MRI techniques may be necessary 1

Common Pitfalls

• Misdiagnosing gluteal tendinopathy as trochanteric bursitis, leading to inappropriate management
• Relying solely on clinical examination without confirmatory imaging
• Using ultrasound as the only diagnostic tool when MRI is available and not contraindicated
• Failing to consider coexisting pathologies (labral tears, hip osteoarthritis)

By using MRI as the primary diagnostic tool for gluteal tendinopathy, clinicians can accurately identify the pathology and implement appropriate treatment strategies to improve patient outcomes.