Hip > Stress Fractures

What are Stress Fractures?

A hip stress fracture is a disruption in the normal structure of your upper thighbone or hipbone. It differs from an acute fracture because it is due to repetitive stress from forces lower than the force necessary to produce an acute fracture. Stress fractures usually begin as small areas of damaged bone that gradually worsen as you continue to strain you hip joint. The severity of bone damage in your hip can vary. Your femoral neck, which is the shaft of bone that branches off at the top of your thighbone and connects to the hip joint, is the most common area affected by stress fractures in the hip. The front of the upper hipbone, called the iliac crest, less frequently suffers stress fractures.

Stress fractures are commonly caused by the cumulative effect of repeated minor stress on your hip joint. Stress fractures typically develop over a varying period of weeks or months, depending on factors like the strength of your bones and your level of activity. Sports that involve repetitive, stressful hip motions, like long distance running, or high speed changes of direction, such as ice hockey, put athletes at the highest risk of hip stress fractures. Hip stress fractures often occuer in long distance female runners who have amenorrhea or anorexia. Stress fractures often develop because of training errors. This means increasing the intensity or duration of your workouts faster than your body can handle. For example, people who are out of shape may be at particular risk of developing hip stress fractures when aggressively beginning a new running workout. Running on hard surfaces or uneven roads may also put abnormal strain on your hip joint that can lead to stress fractures. Losing bone strength can put some people are at risk of stress fractures during repetitive or stressful workouts. Your hipbones tend to weaken with age. Post–menopausal women seem particularly at risk of stress fractures. Low calcium intake may also be related to weaker hipbones. Abnormal biomechanics in your legs can increase the risk of hip stress fractures. Twisting or bending of your shinbone or thighbone may awkwardly transmit weight into your hip joint. High rigid arches or flat feet also may alter the mechanics of your running stride and put you at risk for hip stress fractures. Running in old, worn–out sneakers may accentuate any abnormalities in your foot or leg anatomy.

If stress fractures are left untreated in your hip, you may be at risk of suffering a debilitating acute fracture in the future. This is particularly true for patients over age 65. Untreated stress fractures may also lead to a dangerous condition called avascular necrosis. Another group at risk of suffering hip stress fractures are female runners who are misdiagnosed and told they have suffered groin pulls by trainers, coaches, or physicians. Conditions that lead to weaker bone structure, like osteoarthritis and osteoporosis, also increase the risk of stress fractures turning into acute fractures. Most hip stress fractures in younger patients can be treated in six to eight weeks without surgery by resting and using crutches until X–rays or bone scans show the bones in your hip joint have healed. When a femoral neck stress fracture is clearly visible on an X–ray, the bone usually has suffered significant damage and your physician may monitor your hip closely. You may need to have your femoral neck surgically aligned (open reduction) and reinforced (internal fixation) with pins or screws. If the stress fracture is located on the upper part of the femoral neck, it typically is a tension injury and requires surgery to stabilize the fracture. If the fracture is on the lower part of the femoral neck, it typically is a compression injury and surgery usually is not recommended. Patients over age 65 may have surgery prescribed earlier to stabilize their bones if the risk of acute fracture is high.

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

Your physician may ask you about the following information to help make the diagnosis:

   Your age and history of other medical conditions.

   The nature of your pain – when it began; how long it lasts; its location and severity; whether it radiates; and any factors, like running or climbing stairs, that relieve or increase the pain.

   Your physical and athletic goals – information that will help determine what treatment might be best for you in achieving those goals.

   Whether you have fever, chills, weight loss, or other symptoms of illness.

   Whether you have recently increased the duration or intensity of your workouts or training.

Your physician usually feels around your hip area, looking for painful spots, as your leg is moved in different directions. However, hip stress fractures may not cause any tenderness to the touch. You may be asked to take a "hop test" that requires you to hop on one leg so your physician can see how quickly the pain occurs.

To make the final diagnosis, your physician usually needs to take a closer look at your hipbone and thighbone. A bone scan, where a harmless radioactive dye is injected into your hip joint, typically is the clearest way to differentiate a stress fracture from soft tissue damage. You may also be given X–rays and MRI (magnetic resonance imaging) scans, but stress fractures are harder to see in these images, especially in the early stages when your bone has not been badly damaged.

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