Osteoporosis – brittle bone disease

Osteoporosis is a chronic, progressive disease characterized by reduced bone mineral density and weakened microstructure of bone tissue.This makes the skeleton more susceptible to low-energy fractures, also known as fragility fractures. The condition has a multifactorial etiology and develops gradually with age.

World Health Organization (WHO) definition

In 2004, the World Health Organization (WHO) defined osteoporosis as a bone mineral density (BMD) 2.5 standard deviations or more below the average value for young, healthy women (T-score < –2.5 SD)¹. This definition applies to postmenopausal women and men over 50 years of age. For younger adults and children, the classification is not diagnostically relevant².

Despite the need for standardized thresholds, it is recommended that BMD values should not be the sole basis for treatment decisions.

From BMD to risk-based assessment

Over the past 15 years, clinical practice has shifted from a narrow focus on T-score to a broader assessment of future fracture risk³. Many patients who sustain fragility fractures do not, in fact, have T-scores that meet the osteoporosis definition³. This highlights the importance of evaluating both bone mass and other risk factors.

Consequences of osteoporotic fractures

Osteoporotic fractures significantly reduce quality of life and often lead to permanent functional impairment, increased morbidity, and higher mortality. More than half of white postmenopausal women will experience an osteoporosis-related fracture. Only one-third of elderly women with hip fractures regain independence.

In white men, the risk of osteoporotic fractures is around 20%, but mortality after hip fracture is twice as high as in women. African American men and women have a lower prevalence of osteoporosis, but those affected face a similarly high fracture risk⁴.

Related terms

• Osteopenia: A milder reduction in bone mineral density compared with osteoporosis.

• Sarcopenia: A condition characterized by progressive loss of muscle mass and function, increasing the risk of disability and death⁵.

Causes and types of osteoporosis

Physiology and normal bone metabolism

Bone tissue is continuously renewed throughout life. When bone resorption occurs faster than bone formation, bone mass decreases. This imbalance arises particularly with increasing age. Peak bone mass is reached in the 20s, and low peak bone mass increases the risk of osteoporosis later in life⁶.

Primary osteoporosis

Has no single cause, but several factors contribute:

• Negative calcium balance

• Estrogen deficiency

• Inactivity

• Reduced endocrine function

Subtypes:

• Postmenopausal osteoporosis: Caused by reduced estrogen levels⁷. Women may lose up to 1% of bone mass annually for up to eight years after menopause⁸.

• Senile osteoporosis: Age-related bone loss that increases with advancing age⁷.

• Idiopathic juvenile osteoporosis: A rare form occurring in children and adolescents without known cause.

Secondary osteoporosis

Caused by underlying disease or medication interfering with bone metabolism⁷. Examples include:

• Low calcium intake or poor absorption

• Alcohol abuse – reduces calcium absorption⁹

• Immobilization – bone tissue requires loading to be maintained⁹

• Endocrine disease – hormonal disturbances in gonads, thyroid, adrenal, or parathyroid glands⁹

Common causes of secondary osteoporosis:

• Endocrine: hypogonadism, Cushing’s, hyperthyroidism, hyperparathyroidism, diabetes mellitus

• GI: inflammatory bowel disease, malabsorption, primary biliary cirrhosis, lactose intolerance

• Rheumatologic: inflammatory connective tissue disorders

• Hematologic: myeloma, leukemia

• Medications: glucocorticoids, cytostatics, antiepileptics

• Other: immobilization, alcoholism, organ transplantation, genetic disorders such as Marfan syndrome, osteogenesis imperfecta, glycogen storage diseases¹⁰,¹¹

Risk factors and epidemiology

Risk factors for osteoporosis include¹²:

• Age ≥50 years

• Female sex

• White or Asian ethnicity

• Genetic predisposition (familial osteoporosis)

• Low body weight (<58 kg), small frame

• Amenorrhea, late menarche, early menopause

• Physical inactivity or immobility

• Medication use (corticosteroids, thyroxine, heparin, insulin)

• Alcohol and tobacco use

• Hormone deficiency (androgen/estrogen)

• Vitamin D and calcium deficiency

• Dowager’s hump (kyphotic posture in the thoracic spine)

Prevalence:

• Over 200 million people worldwide have osteoporosis

• 70% of individuals over 80 years are affected

• More common in women than men¹³

• In the developed world, 2–8% of men and 9–38% of women are diagnosed

• 9 million fractures per year globally are caused by osteoporosis

• 1 in 3 women and 1 in 5 men over 50 will sustain an osteoporotic fracture

• Sunlight and latitude play a role: lower vitamin D exposure increases fracture rates⁴

• In the US, over 10 million already have the diagnosis, and an additional 34 million are at risk. Altogether, 55% of the population over 50 is affected¹⁴

Diagnosis and clinical assessment of osteoporosis

How is the diagnosis made?

The diagnosis of osteoporosis is based on both imaging and laboratory tests. All patients with suspected osteoporosis should be evaluated for:

• Kidney and thyroid function

• 25-hydroxyvitamin D and calcium levels

• DEXA scan – WHO considers dual energy X-ray absorptiometry (DEXA) of the central skeleton the gold standard for assessing bone mineral density.

Interpretation:

• T-score between –1 and –2.5 indicates osteopenia

• T-score below –2.5 confirms osteoporosis

In addition, the FRAX tool (Fracture Risk Assessment Tool) is used to estimate the 10-year risk of fragility fractures. FRAX considers both bone mineral density and lifestyle and health factors influencing bone quality⁷.

Other available tools include the Garvan Fracture Risk Calculator and conventional radiography for semiquantitative assessment of existing fractures.

In suspected secondary osteoporosis, the following should be considered:

• 24-hour urinary calcium

• Parathyroid hormone (PTH)

• Testosterone and gonadotropins (in younger men with low BMD)

• Biomarkers of bone resorption and bone formation

Clinical picture and examination

Physical examination usually reveals little in the early stages. In advanced disease, the following findings may occur:

• Reduced height

• Thoracic kyphosis due to compression fractures

• Marked postural change (Dowager’s hump)

Screening recommendations:

• Women: from age 65

• Men: from age 70

• Earlier evaluation is recommended if risk factors are present⁴

Symptoms, comorbidity, and treatment

Common symptoms in advanced osteoporosis:

• Episodic, acute back pain (especially thoracic and upper lumbar)

• Vertebral compression fractures

• Fractures of hip, wrist, or upper arm

• Reduced height

• Kyphosis and postural instability

• Reduced activity level

• Early satiety due to kyphosis and reduced abdominal space⁵

Common comorbidities include¹⁵:

• Eating disorders

• Cancer and cancer therapy

• Chronic kidney disease

• Osteogenesis imperfecta

• Rheumatic diseases

• COPD

• Cushing’s disease

• Hypogonadism in men

• Hypothyroidism / hyperparathyroidism

• Type 2 diabetes

• GI and liver diseases

Pharmacological treatment of osteoporosis

Even small increases in bone mineral density through pharmacological treatment can lead to significant reduction in fracture risk.

• Hip: BMD increase of 1–3%

• Spine: BMD increase of 4–8%

• Fracture reduction: 30–70% for spine, 30–50% for hipEffect is often seen already after 6–12 months of treatment.

Drug classes

• Bisphosphonates– Oral tablets daily, weekly, or monthly: Alendronate (Fosamax), Risedronate (Actonel)– Annual infusion: Zoledronic acid (Aclasta)

• Denosumab– Injection every 6 months: Prolia– Inhibits bone resorption and provides similar effect as bisphosphonates

• SERMs (Selective Estrogen Receptor Modulators)– Daily tablet: Raloxifene (Evista)– Acts like estrogen on bone tissue and reduces the risk of spinal fractures in postmenopausal women

• Hormone replacement therapy (HRT)– Estrogen, possibly combined with progestin– Effective for women under 60 years with both hormone needs and osteoporosis symptoms– Recommended in early menopause (<45 years)

• Teriparatide– Daily injection for 18 months: Forteo– Stimulates bone-forming cells. Used only in severe osteoporosis where other treatment has failed– Requires subsequent therapy to maintain new bone mass

• Romosozumab– Monthly injection: Evenity– Monoclonal antibody that both stimulates bone formation and inhibits bone resorption¹⁷,¹⁸

Lifestyle advice in osteoporosis

Medication is only one part of treatment. Important additional measures include¹⁹:

• Regular weight-bearing and strength-based exercise

• Proper nutrition: sufficient calcium and vitamin D intake

• Smoking cessation

• Limited alcohol consumption

Physiotherapy and exercise-based treatment in osteoporosis

Exercise as treatment

Physiotherapy plays a crucial role in the management of both osteoporosis and osteopenia. The aim is to strengthen the skeleton, improve balance, and reduce the risk of falls and fractures – particularly in older adults, where bone density naturally decreases with age²⁰.

An effective physiotherapy program should include:

• Weight-bearing exercises– Activities such as walking and light jumping can help maintain or increase bone density– The effect is greatest in directly loaded areas, such as the hip and lower extremities

• Strength training– Exercises with dumbbells, resistance bands, or machines strengthen the musculoskeletal system– Local loading at muscle attachment sites can improve bone density in the specific area

• Flexibility and mobility training– Activities such as yoga and tai chi improve movement control and postural function– Reduced stiffness enhances mobility and quality of life

• Balance exercises– Fall prevention is essential. Programs such as Otago are well documented for older adults at high risk of falling²¹– Good postural control significantly reduces fracture risk

Postural training

Osteoporosis often leads to structural changes in the upper body, especially thoracic kyphosis. Therefore, specific extension exercises must be included:

• Chin tucks

• Scapular retractions

• Thoracic extension

• Hip extension

These exercises strengthen the body’s extensors and improve posture and balance. Flexion and rotation of the spine are contraindicated, especially in individuals at risk of compression fractures. Such movements increase anterior compression forces and may trigger vertebral fractures⁷,²².

Pain management and functional rehabilitation

Back pain is a common issue in patients with osteoporosis. Physiotherapists may effectively use:

• Agility training

• Strength training

• Stretching

These interventions reduce back pain and improve function in this patient group²³.

High-intensity training

Recent research supports the use of high-intensity strength and bodyweight-based exercise for women in menopause and early postmenopausal phases. Exercises should be functional and performed in circuit training formats²⁴.

Effect of different training types²⁵:

• Dynamic, weight-bearing, high load → greatest improvement in femoral neck, moderate in greater trochanter

• Dynamic, weight-bearing, low load → moderate effect on the spine

• Static, non-weight-bearing, high load → moderate effect on the femoral neck

Clinical considerations and precautions

• Manipulation and manual techniquesManual treatments and manipulation must be used with great caution. Increased fracture risk – especially in the spine – always requires individual assessment.

• Treadmill with weight supportContraindicated in severe osteoporosis (T-score < –2.5) and in fractures of the lower extremities, pelvis, or ribs²⁸.

• Plyometric training and balance exercisesShould be performed with particular caution, and always after a thorough fall-risk assessment.

Practical advice and patient education

Patients with osteoporosis should receive simple and clear lifestyle advice:

• Ensure adequate calcium and vitamin D intake through diet

• Wear supportive shoes – avoid slippers and loose sandals

• Remove loose rugs and improve stair lighting

• Have vision checked regularly

• Avoid heavy lifting – consider home delivery of groceries

Nutrition and multidisciplinary follow-up in osteoporosis

Calcium and vitamin D – essential for bone health

Two of the most important nutrients for people with osteoporosis are calcium and vitamin D. Calcium is a key building block of bone tissue, while vitamin D is necessary for the body to absorb calcium effectively.

• Calcium can be obtained through food, supplements, or both – but it is generally recommended to meet requirements primarily through diet.– Recommended intake for adults over 50 is 1000–1200 mg of elemental calcium daily²⁹,³⁰.

• Vitamin D can be obtained in three ways:– Food: Fatty fish, egg yolks, and fortified foods– Sun exposure: Regular short exposures without sunscreen. As a rule of thumb, your shadow should be shorter than yourself – otherwise little vitamin D is produced³¹– Supplements: The recommended daily dose for adults over 50 is 700–800 IU vitamin D²⁹,³⁰

Multidisciplinary approach and patient education

Osteoporosis is a major public health challenge, affecting millions of older adults and leading to physical, psychosocial, and economic consequences. The condition has many risk factors, requiring follow-up by a multidisciplinary healthcare team.

Effective management includes:

• Early prevention and awareness of consequences

• Physiotherapy with tailored exercise programs and functional follow-up

• Lifestyle modification – smoking cessation, reduced alcohol intake, dietary advice

• Medication adherence – support and information from pharmacists

• Nutritional counseling – dietitian guidance on calcium and vitamin D

• Screening – women over 65 should undergo bone mineral density testing⁴

Patient education is crucial. Many are unaware of the seriousness of the disease and achieve better outcomes when provided with practical advice, structure, and motivation over time.

Conclusion

Osteoporosis is a silent and very common disease, often first detected when fractures have already occurred. Around 50% of women and 20% of men over 50 will sustain a fracture related to osteoporosis during their lifetime.

Such fractures cause lasting functional impairment, pain, and reduced quality of life. They also increase mortality and represent a heavy economic burden for both patients and society.

However, the disease can be prevented, diagnosed, and treated – often before fractures occur. Early intervention, proper treatment, and comprehensive follow-up are key to protecting the skeleton and maintaining quality of life in older age³².

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