What Imaging Technique Correlates Best with Surgical Findings in Gluteus Medius Tendon Tears?

Background/Objectives: Gluteal medius tendon tears (GTT) are a common cause of greater trochanteric pain and functional impairment. Accurate preoperative imaging is critical for diagnosis and surgical decision-making. This study aimed to evaluate and compare the diagnostic accuracy of four imaging modalities-X-ray, ultrasound (US), magnetic resonance imaging (MRI), and bone scan (BS)/SPECT/CT-in detecting and grading GTT, using perioperative findings as the reference standard. Methods: In this prospective study, a cohort of 45 patients (41 women, 4 men; mean age 62.9) with suspected GTT and failed conservative treatment had open surgical treatment by augmentation of the gluteus medius tendon. All patients underwent preoperative imaging with X-ray, US, MRI, and BS. Imaging results were compared with intraoperative findings. Results: MRI demonstrated the highest sensitivity (98%) and strong PPV (91.1%), correctly identifying nearly all true positives. Ultrasound showed similar sensitivity (95%) but yielded more false positives. X-ray and BS exhibited perfect specificity and PPV (100%) but poor sensitivity (21% and 38%, respectively), limiting their utility in ruling out GTT. Conclusions: MRI is the most sensitive and reliable single modality for diagnosing GTT, though false positives remain a concern in surgical decision-making. Ultrasound, while sensitive, lacks specificity and should not be used in isolation for surgical decision-making. A multimodal imaging approach, particularly combining MRI with X-ray and BS, may offer high diagnostic certainty and help prevent unnecessary surgical interventions.