Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA

Snapping Hip Syndrome

1. Basic Concept

A snapping hip is a clicking or snapping sensation that occurs during hip movement.

It may be:

• Painful
• Painless

There are three main types:

1. Internal
2. External
3. Intra-articular

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2. Internal Snapping Hip

Cause

The iliopsoas tendon snaps over bony structures around the anterior hip.

It may snap over:

• Iliopectineal eminence
• Pelvic brim

The lecture also associates it with inflammation of the iliopsoas bursa, which lies between the anterior hip joint and the iliopsoas muscle or tendon.

Diagnosis

Diagnosis can be difficult.

Ultrasound or MRI may be normal, although they may demonstrate:

• Fluid within the bursa anterior to the hip joint

An iliopsoas tendon injection can be diagnostic.

Clinical Test

The diagnosis can be supported by:

• Hip abduction
• External rotation

If this reproduces the snapping or clicking, it supports an internal snapping hip.

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3. External Snapping Hip

The external type is described as iliotibial band syndrome.

Cause

The iliotibial band becomes thickened and snaps over the:

Greater trochanter

Associated problems may include:

• Bursitis
• Adhesions
• Gluteus maximus inflammation
• Edema

Clinical Examination

Direct palpation over the greater trochanter may reproduce the snapping.

The patient can also be positioned on the side while the examiner places the hip into extension and rotation and feels for the pop.

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4. IT Band Tightness Test

The lecture describes a test for assessing iliotibial band tightness.

Position

• Patient lies on the side.
• Unaffected leg is positioned underneath.
• Examiner abducts the affected leg.
• Examiner extends the hip.
• The leg is then allowed to lower.

Positive Test

The leg cannot descend past anatomic neutral because of IT band tightness.

The lecture describes this as the knees being unable to come together.

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5. Intra-articular Snapping Hip

The intra-articular type originates from pathology within the hip joint.

Important causes include:

• Labral tear
• Loose body

Clinical Features of Labral Tear

A patient may have:

• Decreased range of motion
• Painful clicking
• Mechanical symptoms within the joint

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6. MRI Arthrogram for Labral Tear

The lecture describes the labrum as a black triangular structure on the MRI arthrogram.

The contrast relationship to the labrum is important.

Normal

Contrast may enter the lateral recess adjacent to the labrum.

This is described as normal and does not necessarily indicate a tear.

Labral Tear

Contrast extending medial to the black triangular labral structure indicates a tear according to the lecture.

Best Investigation

MRI arthrogram is described as the best study for diagnosing a labral tear.

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Quick Comparison

Feature	Internal	External	Intra-articular
Main structure	Iliopsoas tendon	Iliotibial band	Labrum / loose body
Location	Anterior hip	Greater trochanter	Within hip joint
Mechanism	Iliopsoas snapping	IT band snapping over greater trochanter	Intra-articular pathology
Key examination	Abduction + external rotation	Palpation over greater trochanter, IT band tightness test	Painful click + reduced ROM
Imaging	US/MRI may be normal	Mainly clinical	MRI arthrogram
Important associated pathology	Iliopsoas bursitis	Bursitis, soft-tissue inflammation	Labral tear, loose body

Exam Pearls

• Internal snapping – iliopsoas tendon
• External snapping – IT band over greater trochanter
• Intra-articular snapping – labral tear or loose body
• Anterior snapping – think iliopsoas
• Lateral snapping – think IT band
• Painful click + reduced ROM – think labral pathology
• Iliopsoas injection can be diagnostic
• MRI arthrogram is the best study for labral tear
• Contrast in the lateral recess can be normal
• Contrast medial to the labral structure indicates a tear according to the lecture.