Snapping Hip Syndrome

Snapping hip is exactly what it sounds like — a snap, click, or pop you can hear or feel at the hip when you move it a certain way. There are three flavors. External is when the thick band of tissue running down the outside of your thigh (the IT band) flips over the bony bump on the side of your hip. Internal is when one of the deep hip-flexor tendons in your groin (the iliopsoas) catches on a bony ridge inside the front of the hip. Intra-articular is when something loose inside the joint itself — a piece of cartilage, a tear in the rim of the socket — is what's snapping.

External and internal snapping are common in dancers and gymnasts and often don't hurt at all — they can be more entertaining than worrying. When the snap is painful, or when we suspect something is loose inside the joint, that's when it's worth a workup.

Snapping hip is a recognized complication after total hip replacement (THA), most often caused by the iliopsoas tendon — the deep hip flexor that crosses the front of the joint — catching on a prominent edge of the acetabular cup or, less commonly, on the femoral component or a fixation screw. Published series put the prevalence at roughly 4 to 7 percent of patients after THA, though it is likely under-reported because many cases settle without specific treatment.

The classic presentation is anterior groin pain that comes on with hip flexion against resistance: getting up from a low chair, climbing stairs, putting on socks or shoes, or getting in and out of a car. Patients often describe an audible or palpable snap or click in the front of the hip, with tenderness right where the iliopsoas tendon crosses the front of the joint. Pain at rest is unusual; pain with motion that loads the hip flexor is the rule.

Imaging starts with standing X-rays to look for cup overhang or component malposition. CT gives a more precise read on the geometry — how much of the cup edge is uncovered by bone in front, and whether the femoral component or fixation screws sit prominently in the path of the tendon. The most useful diagnostic test is an image-guided iliopsoas tendon sheath injection: if temporarily numbing the tendon substantially relieves the pain, the iliopsoas is confirmed as the source.

Treatment progresses through a typical conservative ladder before any operative consideration. Activity modification (avoiding the specific positions and loads that flare the pain) is the first move. Targeted physical therapy works on lengthening the hip flexor and retraining gait and movement patterns. An image-guided iliopsoas injection serves both diagnostic and therapeutic purposes — many patients get durable relief from one or two well-placed injections. When non-operative care does not settle the pain, the surgical options are an arthroscopic or open iliopsoas tenotomy (release of the tendon) or revision of the acetabular component if cup malposition is clearly the mechanical cause.

OSI evaluates post-THA hip pain and coordinates the workup. Image-guided iliopsoas injections and revision arthroplasty are referred to a trusted partner when those steps become the right call.

• An audible or palpable snap, click, or pop at the hip — typically with a specific reproducible movement
• External type: snapping on the outside of the hip when you walk, run, or swing your leg forward
• Internal type: a deep snap or click in the groin when you bring your hip from a bent to a straight position
• Pain may or may not accompany the snap — many cases are painless and just noticeable
• Aching at the side of the hip or in the groin after repetitive activity (dance, running, cycling)
• A sensation of the hip "giving way" or catching during certain movements

Your provider can usually reproduce the snap on exam. External snapping you can both see and feel at the side of the hip; internal snapping is felt in the groin and is often audible. The most useful imaging is a live ultrasound (the technician moves your hip while watching the screen) — it lets us actually see the tendon flicking over bone. If we suspect a problem inside the joint, an MRI with contrast injected into the joint (MRI arthrography) shows the labrum and any loose bodies.

1. Corticosteroid injection

   An image-guided steroid injection placed into the inflamed bursa next to the snapping tendon takes the edge off when stretching alone hasn't quieted the pain.

Surgery is rarely needed for snapping hip. When the snap is painful and hasn't quieted with six months or more of stretching, therapy, and injection, we can lengthen or release the offending tendon through small incisions (an endoscopic procedure).

External patient-education references and related OSI pages for additional background:

• Britannica — Hip (anatomy)
• AAOS OrthoInfo — patient education library
• OSI glossary — orthopedic terminology in plain language