A fracture is a broken bone. Occult means hidden. An occult fracture is one that does not appear well on an X-ray. A possible occult fracture is a suspected fracture that needs to be confirmed with other imaging tests.
Occult fractures can occur because of a fall or other type of sudden (acute) injury. They can also occur because of repetitive injuries or normal stresses on weak bones. Fractures caused by repetitive injuries are fatigue fractures. Those that result from normal stresses on weak bones are insufficiency fractures. Another name for these fractures is stress fractures.
Common sites for occult fractures include the hip, shin, upper arm, and the bones of the ankle, foot, wrist, and spine. Stress fractures are more common in the lower part of the body than in the upper part. They are also more common in women than in men. They often occur in athletes and military recruits.
Accidents such as falls cause some occult fractures. The rest are caused by repetitive activities or weakened bones.
Repetitive activities such as running, marching, and throwing can cause fatigue fractures. These injuries often occur in people who suddenly increase their activity level. Their actions cause tiny cracks in the bone. Normally, the bone is able to repair these small fractures. But that requires time. When the activity continues or happens again before the repairs are complete, these small fractures can add up to form a stress fracture. In extreme cases, ongoing activities can cause sudden larger fractures.
Insufficiency fractures occur in weak bones. Bones can weaken enough that they can't withstand normal stresses caused by walking, twisting, or other low-impact activities. Causes of weak bones include:
Bone loss (osteoporosis)
Genetic disorders such as osteogenesis imperfecta
Exposure to radiation or chemotherapy
Long-term steroid use
You may have an increased risk for occult fractures if you:
Have a condition that weakens bones
Are not physically fit
Are a military recruit
Engage in certain athletic activities
Sports that raise the risk for leg, ankle, and foot fatigue fractures include long-distance running, track and field, basketball, football, soccer, and dance. Fatigue fractures of the spine are more common in gymnasts, volleyball players, football players, dancers, and cheerleaders. Shoulder and arm fatigue fractures can occur in pitchers, cheerleaders, and gymnasts.
Other things that can raise your risk include:
Abnormal or absent periods (in women)
Poor nutrition or eating disorders
High arches or flat feet
Previous stress fractures
Having more than 10 alcoholic beverages a week
The most common symptom of an occult fracture is pain. You may notice that the pain gets worse with activities and improves with rest. Even walking, or just putting weight on your leg may cause pain. If you have an occult fracture of your hip, you may not be able to walk. Occult fractures typically cause pain in a specific area, rather than pain that is widespread. You may feel a sudden increase in your pain if you develop a larger fracture after continuing to put stress on the bone.
Your healthcare provider will ask about your recent symptoms and your past health. On exam, he or she may note a specific area of tenderness, pain with certain movements, and swelling.
Your healthcare provider will send you for X-rays. The X-rays can show any sign of a broken bone. If they look normal despite a suspected fracture, you may need repeat X-rays in about 2 weeks or other imaging tests. These may include:
Bone scan (bone scintigraphy)
Occult fractures often show up on MRI scans. But MRIs are expensive. They may also take longer than other imaging tests and are not available everywhere. You may not be able to t have an MRI if you have a pacemaker.
Newer CT scans are an alternative to MRI scans. They are often a good choice when you can't have an MRI scan. Before the newer CT scans, healthcare providers often used bone scans. Although occult fractures often show up on bone scans, it's hard to find their exact location. Ultrasound is another option. The provider can quickly do a scan with ultrasound.
The treatment of an occult fracture depends on where it is. Sometimes the combination of rest with splinting or casting is enough. If you have an occult fracture of your leg, ankle, or foot, you may need to use crutches to keep all of your weight off your injury. Or you can use crutches to limit the amount of weight you put on it. You may also need to wear a walking cast or boot as it heals.
Your healthcare provider may refer you to a sports medicine doctor or an orthopedist for treatment. That’s especially the case if you have an occult fracture of the spine, hip, lower leg, ankle, or foot. Sometimes occult fractures need to be treated with surgery. The bone can then be fixed with pins, screws, or metal plates.
Bones heal through a process of knitting. Cells within the bone lay down new bone building blocks and remodel them until the bones become reconnected and strengthened. This healing process may take several weeks to several months. Even after the bones have started to heal, it may still be some time before they can handle the stresses they used to.
When you have your cast or splint removed, you will probably find that your muscles are weaker than they used to be. Once it's OK to resume activities, your healthcare provider may send you to rehabilitation specialists. They can help you learn exercises to rebuild your strength and flexibility and to prevent future fractures.
If your fracture is not diagnosed promptly and treated, the bone may not heal properly. Sometimes complications occur even after proper treatment. Possible complications of an occult fracture include:
Death of bone because of decreased blood supply (avascular necrosis)
Accidents happen, but you can take certain precautions to lower your risk for accidents and of injuries from accidents. You can also take precautions to reduce your risk for stress fractures. Here are some things you can do to lower your risk:
Eat a healthy diet that is rich in calcium and vitamin D.
Wear properly fitting shoes with cushioned insoles. Replace them every 3 to 6 months.
Increase your activity level slowly and take rest breaks.
Cross-train and do strengthening exercises.
If you have a risk of falling, install safety bars in your home.
Remove tripping hazards.
If you have a condition that weakens bones, talk with your healthcare provider about ways to strengthen them.
Call your healthcare provider if you:
Have pain with activity that doesn't go away
Have ongoing pain after an injury
Have a sudden increase in your pain
A possible occult fracture is a suspected broken bone that doesn't show up on X-rays.
Accidents, repetitive injuries, and normal stresses on weak bones can all cause occult fractures.
The pain from occult fractures gets worse with activity.
MRI is one of the best tools for diagnosing occult fractures. But it is not always an option.
Rest can help prevent and treat occult fractures.
Tips to help you get the most from a visit to your healthcare provider:
Know the reason for your visit and what you want to happen.
Before your visit, write down questions you want answered.
Bring someone with you to help you ask questions and remember what your provider tells you.
At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
Know what to expect if you do not take the medicine or have the test or procedure.
If you have a follow-up appointment, write down the date, time, and purpose for that visit.
Know how you can contact your provider if you have questions.