Hip > Acetabular Tear

What is the Acetabular Labrum?

Your acetabulum is the round socket on the side of your pelvis that forms the hip joint along with the head of the thighbone (femur). The acetabular labrum is a horseshoe-shaped fibrocartilage lip that attaches to the rim of the acetabulum and extends the depth of the acetabular socket. The labrum stabilizes the top of your thighbone in the hip joint and seals off the fluids that lubricate the cartilage inside the hip socket.

Labral tears are rare ruptures anywhere in the fibrocartilage around the rim of your pelvis' acetabulum (socket). As a result, your thighbone (femur) may lose stability in the socket. The tear also can lead to friction in your hip joint as the fluid that normally lubricates hip cartilage can more easily escape from the joint. Labral tears more commonly occur in the front and top portions of the labrum. Acetabular labral tears often accompany other injuries or conditions in the hip. For example, hip fractures can tear your labrum and the majority of patients with osteoarthritic hips also have labral tears. Patients with acetabular dysplasia (an abnormality during development that results in a misshapen hip socket) often develop labral tears and osteoarthritis of the hip.

Acetabular tears are most often caused by sports that require excessive hip rotation, such as hockey, ice skating, and golf. Activities that palce severe, repetitivr strain on your hip joint, such as jumping, can also lead to acetabular labral tears. Some less stressful activities that involve bending your body forward, like horseback riding, also may strain your acetabular labrum. Traumatic hip injuries, like falls or collisions, which may pop your thighbone out of the acetabular socket, tend to put added strain on the acetabular labrum. Osteoarthritis may weaken your labrum, making you more vulnerable to suffer tears during less stressful activities. Patients with a shallow pelvis socket, a condition called hip dysplasia, may have less bony support holding their thighbone in the hip joint. Their thighbone may be more likely to strain the acetabular labrum tissue and lead to tears.

If left untreated, acetabular labral tears may become a mechanical irritant to the hip joint, which can increase friction in the joint and speed the progress of osteoarthritis in your hip. Physicians generally recommend conservative treatment with medication, activity modification, and physical therapy for about six months before surgery is considered. Surgery typically is only offered after a reasonable course of non-operative care is given. Without surgery, symptoms may subside in younger patients with minor labral tears. Patients who have suffered labral tears in conjunction with other injuries, who have other medical conditions contributing to tissue degeneration in their hip, or who are over age 65 may have surgery prescribed earlier. The use of an arthroscope to treat a torn acetabular labrum is a relatively new procedure, but is becoming more widely used. Because your hip joint is deep within your body and surrounded by many muscles and ligaments, it is less accessible with an arthroscope than other body areas, like the knee and elbow. The most common labral surgery requires a larger incision to access your labrum.

There are three parts to an orthopedic evaluation: medical history, a physical exam, and tests that your physician may order.

Your doctor will likely ask you when you noticed your hip pain, how it has been feeling since the pain began, and if your hip has been previously injured. Physicians also typically ask about other conditions, such as diabetes and allergies, and medications currently being taken. You may also be asked about your physical and athletic goals – information that will help the doctor decide what treatment might be best for you in achieving those goals. You should let your doctor know about any family history of arthritis, as it is often associated with acetabular labral tears.

Your physician usually performs a number of physical tests to check for pain while your hip is in various positions:

   Standing – Your posture, stride, hip alignment, muscle tone, and ability to move from a standing to sitting position will be observed for abnormalities.

   Lying on your back – Your abdomen, lower back, pelvis, and hip joint may be put through range of motion tests where your physician moves your hips and legs in different directions. A snapping sound may be heard when your physician rotates your hip towards your body.

   Lying on your side – Your physician may press on your ITB (iliotibial band) to check for any damage.

   Sitting – your physician may test your muscle strength, reflexes, and sensitivity to touch. Your physician may also check your pulse in your hip.

The physical symptoms are sometimes inconclusive and your physician may need to take a closer look at your hip joint. MRI (magnetic resonance imaging) usually provides the best images of your labrum. Small labral tears may not be visible on MRI scans. Physicians may also order an arthrogram, where dye is injected into the bloodstream so physicians can inspect images for dye uptake in your hip. The final diagnosis may require the use of an arthroscope, a tiny camera about three to four millimeters in diameter, which can be inserted into your hip through a small incision.

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