From the Guidelines
The hip abductor sign, also known as Trendelenburg's sign, is a crucial clinical test that evaluates the function of the hip abductor muscles, primarily the gluteus medius and minimus, and its significance lies in indicating various conditions that may affect morbidity, mortality, and quality of life, such as gluteal tendinopathy, hip osteoarthritis, and greater trochanteric pain syndrome 1.
Clinical Evaluation
The hip abductor sign is positive when a patient stands on one leg and the pelvis drops on the non-weight-bearing side, indicating weakness or dysfunction of the hip abductor muscles on the weight-bearing side. To perform this test, ask the patient to stand on one leg for about 30 seconds while observing the position of the pelvis. In a normal response, the pelvis should remain level or slightly elevate on the non-weight-bearing side.
Diagnostic Implications
A positive sign is significant because it can indicate various conditions including:
- Gluteal tendinopathy
- Hip osteoarthritis
- Greater trochanteric pain syndrome
- Neurological conditions affecting the superior gluteal nerve This sign is particularly important in evaluating patients with hip pain, gait abnormalities, or after hip surgery. According to recent guidelines, MRI hip without IV contrast is usually appropriate for suspected abductor injury, or trochanteric bursitis, or other soft tissue abnormality 1.
Treatment and Management
Treatment depends on the underlying cause but often includes:
- Strengthening exercises for the hip abductors
- Physical therapy
- Addressing any primary pathology The biomechanical basis for this sign relates to the crucial role of hip abductors in maintaining pelvic stability during single-leg stance, which is essential for normal gait mechanics.
From the Research
Clinical Significance of the Hip Abductor Sign
The hip abductor sign, also known as the Trendelenburg sign, is a significant indicator in clinical evaluation, particularly in assessing hip abductor damage and related conditions.
- The sign is associated with tears of the gluteus medius and/or gluteus minimus tendons, which can cause persistent trochanteric pain and weakness of hip abduction 2.
- A positive Trendelenburg sign can point to the possibility of hip abductor ruptures, especially in patients who do not respond to conservative treatment 2.
- The Hip Lag Sign, a new clinical parameter, has been introduced and validated to determine hip abductor damage, with a sensitivity of 89.47% and a specificity of 96.55% 3.
Diagnostic and Therapeutic Implications
- The hip abductor sign is an important clinical indicator of sarcoglycanopathies, with a sensitivity of 76.2% and specificity of 98% 4.
- Hip abductor tears have recently gained recognition as a more prevalent injury than previously thought, and proper diagnosis and treatment are crucial to prevent further complications 5.
- Abductor insufficiency can cause abnormal gait, lateral hip pain, and abduction weakness in both native and prosthetic hips, and surgical reconstruction of the abductor complex may be indicated for patients with chronic tears 6.
Key Findings
- MRI is the most useful examination technique for diagnosing hip abductor tears and related conditions 2, 3.
- The Hip Lag Sign is a reliable and easy-to-perform clinical parameter that can be used to assess hip abductor damage, especially in resource-limited settings 3.
- Early recognition and treatment of hip abductor tears and related conditions are essential to prevent long-term complications and improve patient outcomes 2, 5, 6.