The more than 200 bones of the adult are not only a miracle of stability at the same time quite low weight, but do amazing work in the course of life. In order to maintain their function, they are constantly being set up, rebuilt and rebuilt. With increasing age, however, the degradation often prevails - it comes to osteoporosis.
Whether this danger exists can be determined with the bone density measurement. Osteodensitometry - for those familiar with foreign languages, it quickly becomes apparent that it refers to the measurement ("metric") of the density ("densus") of the bone ("osteo"). Bone density is a measure of how stable the bone is. It is measured on the basis of the calcium salt content, ie the minerals that give the bone its strength. These are mainly calcium phosphate and calcium carbonate. Are these diminished, z. B. after menopause, it comes to bone loss (osteoporosis), ie a reduction in mass and stability of the bone.
If osteoporosis is detected in time, it can be prevented or treated accordingly, thus reducing the increased risk of bone fractures.
How does the bone density measurement work?
Various methods and devices are available for the investigation. Common to all is the principle that rays penetrate the bone and - depending on the density, ie mineral salt content - are attenuated to different degrees. This is true for X-rays (eg in computer tomography) as well as for ultrasonic waves. In the latter case, in addition to the attenuation of the rays, the velocity of the sound waves is also measured on their way through the bone tissue. They have the advantage that they do not pose a radiation burden on the patient; their informative value has been controversial for years. Since it is known for each method how strong the attenuation of the rays is in healthy persons, newly measured values can be compared with this standard value.
When is the bone density measurement performed?
- The main indication is osteoporosis. Significant symptoms, such as bone pain, increased hunchbacks and spontaneous fractures, especially in postmenopausal women, may be grounds for investigation.
- In men, the risk of bone loss is increased, especially in chronic alcohol and nicotine abuse. Many years of diabetes, malnutrition or increased occurrence of osteoporosis in the family can increase the probability.
- By means of the bone density measurement also a - less - bone softening (osteomalacia) due to disturbed installation of minerals in the bones can be recognized.
A first-time bone density measurement is currently paid by the statutory health insurance only if the doctor has a reasonable suspicion of these diseases and at least one bone fracture is present.