Chapter 6. Osteoporosis

Formulating a diagnosis

Components of the diagnosis: form; presence or absence of bone fractures; 10-year probability of fractures according to the FRAX calculator; reduction of bone mineral density by the T-score; dynamics of the disease

Osteoporosis is defined as a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture.

Due to the increasing osteoporosis prevalence with age, the worldwide aging of the population and the changing lifestyle habits, the prevalence of osteoporosis has risen significantly and will continue to in the future. In fact, it is estimated that worldwide, 1 in 3 women and 1 in 5 men, over age 50, will experience osteoporosis fractures in their remaining lifetimes.

The continual resorption and re-deposition of bone mineral, or bone remodeling, is intimately tied to the pathophysiology of osteoporosis.

Form

There are primary and secondary osteoporosis. Primary osteoporosis develops as an independent disease and its share in postmenopausal women accounts for about 95%, in men aged 50 years and older — about 80% of all osteoporosis cases.

Secondary osteoporosis refers to osteoporosis caused by certain medical conditions or medications that can cause bone loss, increase fracture risk, directly or indirectly affect bone remodeling or interfere with the attainment of peak bone mass in younger individuals. Treatment of secondary osteo­porosis is often more complex than treatment of primary osteoporosis, as it depends on the underlying disease.

• Primary osteoporosis:
  • postmenopausal osteoporosis;
  • senile osteoporosis;
  • juvenile osteoporosis;
  • idiopathic osteoporosis.
• Secondary osteoporosis:
  • diseases of the endocrine system: Cushing’s disease or syndrome. Thyrotoxicosis. Hypogonadism. Hyperparathyroidism. Diabetes mellitus. Hypopituitarism, polyglandular endocrine insufficiency;
  • rheumatic diseases: rheumatoid arthritis. Systemic lupus erythematosus. Ankylosing spondylitis;
  • diseases of the digestive system: condition after gastric resection. Mal­ab­sorption. Chronic liver diseases;
  • kidney diseases: chronic renal failure. Renal tubular acidosis. Fanconi syndrome;
  • blood diseases: myeloma, thalassemia, leukemias and lymphomas;
  • other diseases and conditions: immobilization, ovariectomy, chronic obstructive pulmonary diseases, alcoholism, anorexia nervosa, eating disorders, organ transplantation;
  • genetic disorders: osteogenesis imperfecta, Marfan syndrome, Ehlers–Danlos syndrome, Homocystinuria.

Osteoporosis induced by following classes of agents:

• androgen deprivation therapy;
• aromatase inhibitors;
• glucocorticoids;
• selective serotonin reuptake inhibitors;
• thiazolidinediones;
• proton pump inhibitors;
• certain immunosuppressants;
• hormone deprivation therapy;
• certain steroid hormones;
• certain anticonvulsants, antiepileptic drugs;
• anti-coagulants;
• chemotherapy agents (methotrexate).

Presence of fragility fractures

Fragility fractures, which result from low energy trauma, such as a fall from standing height or less, are a sign of underlying osteoporosis. A patient who has sustained one fragility fracture, is at high risk of experiencing secondary fractures, especially in the first two years following the initial fracture.

Common sites for osteoporotic fracture are the spine, hip, distal forearm and proximal humerus. This, however, does not exclude other sites, in­cluding fracture of the humerus, ribs, tibia (excluding the ankle), pelvis and other fe­mo­ral fractures, where osteoporosis fractures can occur partly due to low BMD, especially after the age of 50 years.

Quick tips

Fractures of hand bones, phalanges, skull, foot and ankle are not con­si­dered osteoporotic fractures.

Back pain is a non-specific sign, so it is possible to suspect an osteoporotic compression fracture of the vertebra in combination with at least one of the following signs:

• pain onset at the age over 50 years;
• an indication of a fall from the height equivalent to a man’s height or weight lifting;
• association with an injury;
• previous fractures;
• long-term use of GCS.

Fractures occurring in a setting of low-level or low-energy trauma, defined as falling from standing height or less, are usually considered as osteoporotic [low-energy (“fragile”) fractures].

Fragility fractures are associated with pain, loss of bone mineral density (BMD) and muscle mass, disability, reduced quality of life, increased risk of subsequent fracture, and death.

Advancing age is associated with impaired balance, poorer mobility, vision and cognition, each of which can increase the risk of falls.

Quick tips

A fall is an event which results in a person coming to rest inadvertently on the ground or floor or other lower level falls, trips and slips can occur on one level or from a height.

Falls are an independent risk factor for fractures, including low-energy ones.

Falls in old age are a multifactorial syndrome that consists of a complex interaction of internal (physical, sensory and cognitive changes associated with aging, other medical problems) and external causes, including the environment, which is not accommodated for aging population.