Osteomalacia
| Classification according to ICD-10 | |
|---|---|
| E55.0 | Osteomalacia in adolescence Osteomalacia in childhood |
| M83 | Osteomalacia in adulthood |
| ICD-10 online (WHO version 2019) | |
The osteomalacia , or bone softening is a painful softening ( malacia ) of the bone (Ossa) by a disorder of bone metabolism (ossification disturbed at normal osteoid ), the adult usually by a vitamin D - triggered or calcium deficiency. In childhood, rickets is the most common clinical picture of osteomalacia. Inadequate mineralization of the basic bone substance in osteomalacia leads to increasing flexibility and deformation of the bones as well as dull pain and sometimes pathological fractures .
causes
Osteomalacia (older also osteomalacia ) is a secondary ossification disorder caused by a lack of chemical substances . Histologically , osteomalacia is characterized by an abnormally high ratio of the soft bone matrix to the mineralized bone. There are over 30 known causes and related diseases. The most important causes besides the vitamin D deficiency are:
- Vitamin D hormone - metabolic disorders
- (Chronic) kidney failure , renal tubular dysfunction, e.g. B. Phosphate diabetes in children
- Phosphatase deficiency ( hypophosphatasia )
- Bone matrix disorders
- Fluoride therapy
- Therapy with fumaric acid
Vitamin D deficiency
The vitamin D deficiency often results in muscle weakness and, in the context of osteomalacia, an increased risk of bone fractures, especially for femoral neck fractures . In addition, vitamin D deficiency also appears to increase the risk and severity of numerous chronic diseases, such as tumor diseases, autoimmune diseases, infectious diseases and cardiovascular diseases.
Osteoporosis is associated with osteomalacia, especially in older people . A vitamin D deficiency is particularly common in residents of old people's homes, but in principle also frequently in older people in general. Studies have shown a deficiency in 40–100% of men and women over 65 in Europe and the United States. In addition, adolescents and pregnant or breastfeeding women also have an increased risk of vitamin D deficiency.
diagnosis
The main symptom is generalized or localized bone pain that is dull and persistent. It is assumed that pain develops in the area of the periosteum , which is well innervated. The swelling of the gelatin matrix under the periosteum, which has not been mineralized due to the vitamin D deficiency, raises it and causes pain. An indication is a clear pain provocation with moderate pressure on the breastbone ( sternum ) or the edge of the shinbone, which is usually not painful. In an American study, a vitamin D deficiency was found in 93% of patients between the ages of 10 and 65 who presented because of unspecific muscle and bone pain.
Diagnosing osteomalacia by x-ray can be difficult. Some findings such as osteopenia or coarsening of the trabeculae are very unspecific and not very helpful for the diagnosis . Generally, all you see is diffuse osteopenia, which looks the same as it does in osteoporosis patients. In rare cases, a more specific formation of the unmineralized bone matrix can be seen on X-rays. Curved bones are occasionally seen in adult patients. In general, however, a bone biopsy is much more helpful than an X-ray in diagnosing osteomalacia. Creeping fatigue fractures (pseudofractures) can also be made visible by magnetic resonance imaging . On the other hand, a laboratory determination of the vitamin D level or 25-hydroxyvitamin D helps to identify a deficiency. Likewise, the determination of the known laboratory parameters for other bone metabolic disorders (such as alkaline phosphatase in hypophosphatasia ).
A specific manifestation of osteomalacia is a creeping pathological fracture, particularly on bone sites that are subject to bending stress. In this case, a so-called. Constitutes Looser zone , a fracture line in the bending stress cortical bone ( cortical bone ) with surrounding sclerosis (band-shaped lightening, blurred Spongiosazeichnung transverse to the bone axis), which may expand to a complete fracture and localized pain, early limp and Disabilities leads. Common points are the inner edge of the femoral neck ( Adam's arch ), the inner cortical bone of the thigh ( femur ) and the lower leg front edge, more rarely the shoulder blade or the upper arm bone ( humerus ). In addition to the basic therapy for vitamin D deficiency, relief and pain therapy are usually sufficient. If therapy with vitamin D and calcium is out of the question (e.g. for hypophosphatasia ), prophylactic treatment of the long bones with intramedullary nails is often advisable.
Treatment and prevention
The treatment involves the additional intake of calcium , phosphate and vitamin D. Sunbathing promotes the formation of vitamin D in the skin, cod liver oil contains a lot of vitamin D. As a prophylactic measure, children and adolescents and adults up to 50 years of age should take 200 IU of vitamin D daily , 51–70 year olds 400 IU daily, and over 70 year olds at least 600 IU of vitamin D. In addition to these official recommendations from the American Institute of Medicine , many experts recommend 800–1000 IU vitamin D per day if there is insufficient exposure to the sun.
Since osteomalacia is often accompanied by osteoporosis in older people , this too must be adequately treated.
Vitamin D intake recommendations
DA-CH reference values of the DGE, ÖGE, SGE / SVE
The German Nutrition Society increased the recommended intake for vitamin D in January 2012. She now gives these as “estimated values for an appropriate intake in the absence of endogenous synthesis”; the “intake recommendations” valid until 2012 were made without taking the self-synthesis into account and were on average four times lower. In 2012 the following values were published:
- Infants (0 to under 12 months): 10 µg / day (estimate)
- Children (1 year to under 15 years): 20 µg / day
- Adolescents and adults (15 years to under 65 years): 20 µg / day
- Adults aged 65 and over: 20 µg / day
- pregnant woman: 20 µg / day
- breastfeeding women: 20 µg / day
In summary: all persons 20 µg / day, infants up to 1 year old, half of this dose.
1 µg = 40 international units (IU); 1 IU = 0.025 µg
Between 2008 and 2010, the US health organization Institute of Medicine (IOM) examined the data available to date on vitamin D and its consequences for human health. The aim of the study was to provide specific recommendations regarding vitamin D based on scientific studies. The study found that health benefits beyond bone health for vitamin D levels higher than 20 μg / L are scientifically controversial. The daily requirement for vitamin D was thus set at no more than 600 IU, with the maximum daily dose being increased to 4,000 IU. The recommendation is based on the study of more than 1000 publications on vitamin D, making it the largest vitamin D study in the last decade.
See also
literature
- MF Holick: Vitamin D deficiency. In: N Engl J Med. 2007; 357 (3), p. 266 ff.
- Susan Ott: Pages about osteomalacia (English)
- Ludwig Weissbecker: D-avitaminosis (rickets, osteomalacia, English disease, rickets). In: Ludwig Heilmeyer (ed.): Textbook of internal medicine. Springer-Verlag, Berlin / Göttingen / Heidelberg 1955; 2nd edition ibid. 1961, pp. 1086-1088, and Die Osteomalacie. Ibid, pp. 1127-1129.
Individual evidence
- ↑ Vitamin D requirement in the absence of endogenous synthesis German Nutrition Society, January 2012; Retrieved July 19, 2012.
- ↑ Release from Nov 30. 2010 ( Memento of the original from August 23, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. The Institute of Medicine of the National Academy of Sciences.
