What Gluteal Tendinopathy with Partial Tearing of Gluteus Medius Means
Gluteal tendinopathy with partial tearing of the gluteus medius represents a degenerative condition of the hip's "rotator cuff" where the tendon that stabilizes and abducts the hip has sustained structural damage, causing lateral hip pain, weakness, and potential progression to complete tendon failure if left untreated. 1
Clinical Significance and Pathophysiology
The gluteus medius functions as the primary hip abductor and stabilizer, analogous to the rotator cuff of the shoulder. 2 The condition typically affects the thinner anterolateral portion of the tendon footprint where it attaches to the greater trochanter. 2
- Partial tears most commonly result from chronic degeneration rather than acute trauma, representing a continuum from simple tendinopathy to interstitial tears, then partial-thickness tears, and potentially progressing to full-thickness retracted tears. 2, 3
- The condition is frequently misdiagnosed as trochanteric bursitis, leading to delayed appropriate treatment. 3, 4
- Tears can occur on the articular (deep) side or bursal (superficial) side of the tendon, with undersurface tears being particularly common and challenging to diagnose. 4
Clinical Presentation
Patients typically present with lateral hip pain aggravated by weight-bearing activities and sleeping on the affected side, along with weakness during hip abduction. 2
- Morning stiffness lasting more than 30 minutes in patients under 45 years should raise suspicion for underlying axial spondyloarthropathy, requiring MRI of sacroiliac joints and rheumatology referral. 5
- Trendelenburg gait (hip drop on the contralateral side during single-leg stance) indicates significant tendon dysfunction and represents a poor prognostic sign that should prompt urgent surgical evaluation. 1, 3
Diagnostic Confirmation
MRI without contrast is the definitive diagnostic study, with sensitivity ranging from 33-100% and specificity of 92-100% for detecting gluteus medius tears. 6, 1
- Standard hip radiographs should be obtained first to exclude bony pathology before proceeding to MRI. 1
- MRI provides critical prognostic information including tear size, degree of retraction, and fatty degeneration of the muscle belly, all of which influence treatment decisions and outcomes. 1, 3
- Ultrasound has inferior sensitivity (79%) compared to MRI and should not be relied upon as the primary diagnostic modality for partial tears. 7
Prognostic Factors and Natural History
Tendon retraction and fatty degeneration are poor prognostic factors that worsen with time, making early intervention critical. 1, 3
- Delaying treatment beyond 6 months or waiting for Trendelenburg gait to develop significantly worsens functional outcomes and tendon healing potential. 1, 3
- The condition can progress from partial to full-thickness tears if conservative management fails, particularly with continued loading and inadequate rehabilitation. 3
Critical Pitfalls to Avoid
Do not repeatedly inject corticosteroids into or near the tendon, as this has deleterious effects on tendon substance and accelerates degeneration. 1, 7
- If corticosteroid injection is used, it must be ultrasound-guided into the peritendinous space (not intratendinous), and limited to a single injection as part of a comprehensive treatment plan. 5, 7
- Do not delay surgical referral in patients with full-thickness tears or significant functional deficits, as outcomes deteriorate rapidly after 3 months from injury. 1
- Avoid misinterpreting the condition as simple trochanteric bursitis, which leads to inadequate treatment and progression of tendon damage. 3, 4