Examination of Hip : Trendelenburg test or sign

Normal: When the body weight is supported on one limb, the abductors (gluteus medius and minimus) of the supported side contract and raise the opposite unsupported side of the pelvis.

Abnormal: If the abductor mechanism is defective, the unsupported side of pelvis drops and this is known as positive trendelenburg’s test.

Use: To assess the integrity of abductor mechanism of hip

Causes of positive trendelenburg sign or test:

This test is positive in conditions in which any of the three – fulcrum (femoral head), lever arm (femoral neck length) or power (muscles/nerves) are affected.

Note: The primary abductors of hip are gluteus medius and minimus while tensor fascia lata and sartorius are accessory abductors of hip.

1. Power paralysis of abductor muscles:

• Superior gluteal nerve palsy
• Polio
• Iliotibial tract palsy

2. Decreased lever arm:

• Fracture neck of femur

3. Absence of stable fulcrum:

• Dislocation of hip
• Destruction of femoral head: Perthe’s disease, Avascular necrosis of head of femur, Late stages of TB hip, Septic arthritis