MRI as the Initial Advanced Imaging Modality for Suspected Gluteus Medius/Minimus Tears

Imaging Algorithm

Plain radiographs should be obtained first to exclude fractures or other bony pathology before any advanced imaging is performed in patients with suspected gluteus medius or minimus injuries. 1
Non‑contrast MRI of the hip is recommended as the next imaging study rather than ultrasound for evaluating suspected tendon, muscle, or ligament injury of the gluteal region. The American College of Radiology notes insufficient evidence to support ultrasound in this role. 1

Sensitivity of non‑contrast MRI for gluteus medius/minimus tendon tears ranges from 33 % to 100 %, with specificity between 92 % and 100 %. These values reflect the ability of MRI to correctly identify both partial and complete tears. 1
In pooled analyses, MRI achieved an overall accuracy of 91 %, with 73 % sensitivity and 95 % specificity for detecting gluteus medius/minimus tears. 1

In head‑to‑head studies, MRI identified 100 % of proximal muscle‑tendon injuries, whereas ultrasound detected only 58.3 % of the same lesions. 1
For patients presenting with chronic greater trochanteric pain syndrome, ultrasound demonstrated a sensitivity of 79 % for gluteus medius/minimus tears, indicating lower detection capability compared with MRI. 1

MRI provides a complete evaluation of peritrochanteric structures, including the gluteus medius and minimus muscles, abductor tendons, and the trochanteric bursa. This comprehensive view aids in accurate diagnosis and treatment planning. 1
MRI can classify tear location, extent (partial vs. complete), degree of retraction, and chronicity, information that is essential for surgical decision‑making. 1
MRI also identifies associated pathologies such as ilio‑femoral ligament or ligamentum teres injuries, which may contribute to hip pain and influence management. 1

MRI findings of tear size, retraction, and fatty degeneration help determine whether early surgical repair (within 3 weeks to 3 months) is indicated, guiding timing of intervention. 1
While MRI has limited utility for return‑to‑play decisions in athletes, it remains more informative than ultrasound for this purpose. 1

Do not skip plain radiographs; failure to obtain initial films may miss obvious bony abnormalities that could alter imaging strategy. 1
Avoid using ultrasound as the primary diagnostic tool for gluteus medius/minimus tears; its limited ability to differentiate tendinosis from bursitis reduces diagnostic accuracy. 1
Do not delay MRI in acute full‑thickness tears; early diagnosis enables surgical repair within 3 weeks, which is associated with superior outcomes compared with delayed repair. 1

In patients with hip prostheses, MRI is superior to other modalities for detecting extracapsular disease related to adverse reactions to metal debris, which might otherwise be misinterpreted as bursitis on ultrasound. 1

Ultrasound should be reserved for image‑guided therapeutic injections (e.g., corticosteroid delivery) rather than primary diagnosis of gluteal tendon pathology. 1
It may be used to detect trochanteric bursitis when that is the primary clinical suspicion, though differentiation from tendinosis remains challenging. 1

MRI remains the mainstay for evaluating gluteus minimus/medius tendinopathy with meta-analyses reporting sensitivity ranges of 33-100% and specificity ranges of 92-100% for detecting gluteus minimus/medius tendon tears 2
Ultrasound has shown lower sensitivity (79%) for detecting gluteus minimus/medius tendon tears in patients with chronic greater trochanteric pain syndrome 2
When directly comparing imaging modalities for proximal hamstring avulsion injuries, MRI detected 100% of injuries while ultrasound detected only 58.3% 2

MRI provides comprehensive assessment of all peritrochanteric structures including the gluteus minimus and medius muscles, abductor tendons, and the trochanteric bursa 3, 4
MRI can better classify the location, extent, degree (partial versus complete), and chronicity of tendon injuries 2
MRI is particularly valuable for evaluating associated conditions like iliofemoral ligament and ligamentum teres injuries that may contribute to hip pain 2
The American College of Radiology explicitly states that MRI without contrast is "usually appropriate when evaluating for clinically suspected tendon, muscle, or ligament injury as the source of hip pain" 4

There is insufficient evidence to support ultrasound as the next imaging study for suspected tendon, muscle, or ligament injury according to the American College of Radiology 2
Ultrasound has limited use in return-to-play decisions for athletes with hip injuries 2

Initial radiographs should be obtained first to rule out other causes of hip pain before proceeding to advanced imaging 3, 4
While ultrasound can detect trochanteric bursitis and some tendon pathology, it is difficult to distinguish between gluteus medius tendinosis and bursitis on ultrasound 3, 4
Differentiation between trochanteric bursitis and gluteus medius/minimus tendinosis is clinically important but challenging, as these conditions frequently coexist 3, 4
In patients with hip prostheses, MRI is superior for identifying extracapsular disease associated with adverse reactions to metal debris that could be misinterpreted as trochanteric bursitis 3

Begin with standard hip radiographs to rule out obvious bony abnormalities 5
Proceed with non-contrast MRI of the hip as the definitive imaging study for suspected gluteus medius tendon pathology 2, 6, 5
Consider ultrasound primarily for guided interventions rather than as a primary diagnostic tool 3