Osteoporosis

Original Editors - Alli Castagno and Christy Kaiser  from Bellarmine University's Pathophysiology of Complex Patient Problems project. Top Contributors - Alli Castagno, Christy Kaiser, Kim Jackson, Carin Hunter, Admin, Lucinda hampton, Elaine Lonnemann, Wataru Okuyama, Nikhil Benhur Abburi, Tarina van der Stockt, Rotimi Alao, Margaret Martin, Uchechukwu Chukwuemeka, Scott Buxton, Ewa Jaraczewska, Simisola Ajeyalemi, Tony Lowe, Vidya Acharya, Wanda van Niekerk, Hardik Bhatt, Ajay Upadhyay, Shreya Pavaskar, De Maeght Kim, WikiSysop, 127.0.0.1, Rachael Lowe, Aranka Van de Steene, Wendy Walker, Jess Bell, Ward dirk Merckx and Rishika Babburu   Topic Expert - Margaret Martin
Page Owner - Corinne Birch as part of the One Page Project

Definition/Description

Osteoporosis is defined as low bone mineral density caused by altered bone microstructure ultimately predisposing patients to low-impact, fragility fractures. Osteoporotic fractures lead to a significant decrease in quality of life, with an increased morbidity, mortality, and disability. Over 50% of postmenopausal white women will have an osteoporotic-related fracture. Only 33% of senior women who have a hip fracture will be able to return to independence. In white men, the risk of an osteoporotic fracture is 20%, but the one-year mortality in men who have a hip fracture is twice that of women. Black males and females have less osteoporosis than their white counterparts, but those diagnosed with osteoporosis have similar fracture risks. The aging of the American population is expected to triple the number of osteoporotic fractures 

Etiology

Bone tissue is constantly being absorbed and replaced throughout ones life span. Bone mass decreases when the rate of absorption increases the rate or production; typically occurring with advanced age. Peak bone mass is met at the average age of 20. Those who develop less bone mass prior to this time, have a high chance of developing osteoporosis.

Primary osteoporosis has no known definite cause, but there are many contributing factors associated with the disorder. These include prolonged negative calcium balance, impaired gonadal and adrenal function, estrogen deficiency, or sedentary lifestyle. Postmenopausal osteoporosis is associated with increased bone loss due to decrease production of estrogen. Women commonly lose 1% per year after peak bone density has been met, for up to 8 years post menopause. Senile osteoporosis is an age-related bone loss that often accompanies advanced aging.

Secondary osteoporosis is caused by prolonged use of medications or secondary to another disease or condition which inhibits the absorption of calcium or impedes the body's ability to produce bone.

Low calcium intake or absorption can greatly increase one's risk for developing osteoporosis. Life long calcium intake is crucial in building up bone stock prior to peak levels of bone mass, as well as maintain bone mass after the age of 20. Excessive alcohol consumption can decrease the body's ability to absorb calcium.

Bone produces in response to the load applied to it. Physically active individuals typically have higher bone density, than those who have a sedentary lifestyle.

Hormone levels, either too little or too much, can impede on the body's ability to produce and maintain adequate bone mass. Dysfunction with sex glands, thyroid, parathyroid, or adrenal glands is often associated with osteoporosis.

Epidemiology

Over 200 million people have osteoporosis and the incidence rate increases with age.  

• Over 70% of those over age 80 are affected.  
• It is more common in females than in males.  
• In the developed world, 2% to 8% of males and 9% to 38% of females are affected.  
• Worldwide, there are approximately 9 million fractures per year as a result of osteoporosis. 
• One in 3 females and 1 in 5 males over the age of 50 will have an osteoporotic fracture.
• Areas of the world with less Vitamin D through sunlight compared to regions closer to the equator have higher fracture rates in comparison to people living at lower latitudes.
• In the United States alone, approximately 10 million individuals are estimated to already have the disease and 34 million at increased risk for osteoporosis. Fifty-five percent of Americans over the age of 50 have the disorder. 

Diagnosis

Patients with a diagnosis of osteoporosis should have   

• Laboratory assessment of their renal and thyroid function, a 25-hydroxyvitamin D and calcium level.   
• DEXA scan.The World Health Organization (WHO) established dual x-ray absorptiometry tests scans (DEXA) of the central skeleton is the best test for assessing bone mineral density.  

Bone density test results are reported using T-scores. T-scores are relative to how much higher or lower your bone density is compared to that of a healthy 30 year old adult

A t-score reflects the difference between the measured bone mineral density and the mean value of bone mineral density in young adults. It is measured in standard deviations. The WHO has defined normal bone mineral density for women as a t-score within one standard deviation of the young adult mean. Scores between negative 1 and negative 2.5 reflect a diagnosis of osteopenia. Scores below negative 2.5 reflect a diagnosis of osteoporosis.

The Fracture Risk Assessment Tool, FRAX,  has become a more accurate way to measure 10years fracture probability.  The FRAX questionnaire takes into account elements that influence an individual's bone quality as well as their bone density. 

To learn more about FRAX view this tutorial.

Characteristics/Clinical Presentation

The physical exam rarely reveals any changes until osteoporosis is quite advanced. At that point, loss of height and kyphosis is evident from vertebral fractures.

In healthy individuals without risk factors, experts recommend

• Start to screen women at the age of 65 years of age and men at the age of 70.
• Patients with risk factors or a high score on an osteoporosis risk assessment test should be screened sooner.

Clinical Signs and Symptoms

• Back pain: Episodic, acute low thoracic/high lumbar pain
• Compression fracture of the spine 
• Bone fractures
• Decrease in height 
• Kyphosis
• Dowager’s hump
• Decreased activity tolerance
• Early satiety
  

Associated Co-morbidities

As many diseases increase an individual's risk of osteoporosis, they also may be seen as comorbidities.

• Eating disorders
• Cancer and cancer treatment
• Chronic renal failure
• Osteogenesis imperfect
• Rheumatic diseases
• Chronic pulmonary disease
• Cushing’s Disease
• Male hypogonadism
• Hypothyroidism
• Hyperparathyroidism
• Type 2 Diabetes Mellitus
• Gastrointestinal Disease
• Hepatic disease 

                                                                                                                                             

Antiresorptive medications, such as biphosphonates, calcitonin, denosumab, estrogen, and estrogen agonists/antagonists, work to prevent more bone loss and reduce the risk of fractures.

Anabolic drugs, such as Teriparatide (a parathyroid hormone), work to increase the rate of bone formation and reduce the risk of fractures.

Risk Factors

• Age 50 years and older
• Female gender
• Caucasian and Asian
• Menopause (especially early or surgically induced)
• Family history of osteoporosis or fragility fractures
• Northern European ancestry
• Long periods of inactivity or immobilization
• Depression
• Alcohol (>3 drinks/day)
• Tobacco
• Caffeine (>4 cups/ day)
• Amenorrhea (abnormal absence of menses)
• Thin body build

Other risk factors - Long term use of long-acting benzodiazepines, anticonvulsants or corticosteroids, low testosterone levels in men and anorexia or poor dietary intake

Associated Diseases & Disorders:

Endocrine Disorders:

• Hypothyroidism
• Hyperparathyroidism
• Type 2 Diabetes Mellitus
• Cushing’s Disease
• Male hypogonadism (testosterone deficiency) Malabsorption syndrome:
  
• Gastrointestinal disease; gastric surgery
• Hepatic disease

Medication-related:

Organ transplant

• Chronic pulmonary disease
• Rheumatic diseases, including juvenile rheumatoid arthritis

Other:

• Chronic renal failure
• Osteogenesis imperfect
• Cancer and cancer treatment; skeletal metastases
• Eating disorders
• Spinal cord injury
• Cerebrovascular accident or stroke
• Acid-balance imbalance (metabolic acidosis)
• Depression (men > women)

Medication (>6 months)

• Corticosteroids/steroids
• Immunosuppressants
• Heparin; Coumadin (Wafarin)
• Nonthiazide diuretics
• Methotrexate
• Chemotherapy
• Antacids (containing aluminum)
• Laxatives
• Anticonvulsants
• Some antibiotics
• Buffered aspirin
• Thyroid hormone
• Lithium
• Depo-provera (contraceptive)

Diet & Nutrition

• Calcium and magnesium deficiency
• Vitamin D deficiency
• Vitamin C deficiency (helps with calcium absorption)
• High ratio of animal to vegetable protein intake
• High-fat diet (reduces calcium absorption in the gut)
• Excess sugar (depletes phosphorus)
• Eating disorders or repeated crash dieting
  

Systemic Involvement

An excess of calcium due to the addition of supplements to one's diet can lead to urinary dysfunction, mild diarrhea, or constipation and should be discussed with your doctor if it does not resolve.

In a study performed by Leech JA, Dulberg C, Kellie S, Pattee L, Gay J, the relationship of lung function compared to severity of osteoporosis in women was studied. Results showed that kyphosis and thoracic compression fractures due to osteoporosis can produce modest declines in vital capacity.

Medical Management (current best evidence)

According to Kurt Kennel, M.D., an endocrinology specialist from the Mayo Clinic, the most common medications used to manage osteoporosis are biphosphonates, such as Fosamax, Boniva, Actonel, Atelvia, Reclast, and Zometa. It is also a common practice to use hormones, like estrogen, to help treat and prevent osteoporosis. Some women do not elect to use these hormones due to the increased risk of heart attacks and certain types of cancers. The choice of which drug is right for you is generally based on preference, convenience, and adhering to dosing schedule.

The length of time that a medicine should be used is variable. Most current research shows that biphosphonate medications should be taken up to 5 years for it to be safe and effective. There haven't been enough long-term studies to prove the efficiency of the medications after 5 years of treatment. One thing is known that if you have been taking biphosphonate drugs you can still have positive effects after you stop taking the medications due to building up the medicine in your bone. Due to this effect of the medications, some doctors have patients take a break from the medications after 5 years if they believe they are at a low-risk for fractures.

Medical management helps reduce the risk of fractures but does not eliminate it. If you experience a fracture while taking medications to help treat your osteoporosis you may need to switch to a more aggressive bone-building therapy, such as Forteo (a parathyroid hormone), or a new osteoporosis drug like Prolia or Xgeva. These drugs produce similar or better results than biphosphonates but just work in a different way.

Medical management isn't the only way to treat osteoporosis. It is also important to include daily exercise, good nutrition (including the adequate amount of calcium and vitamin D), quit smoking, and limit your alcohol intake.

Physical Therapy Management (current best evidence)

Physical therapy intervention for individuals with osteoporosis, or even osteopenia, should include:

• weight-bearing
• flexibility exercise
• strengthening exercise
• postural exercise
• balance exercise

Weight-bearing exercises

Exercises such as walking or hopping, has been shown to maintain or improve bone density in this population. Strengthening exercises, using weights or resistance bands, has also be shown to maintain or improve bone density at the location of the targeted muscle attachments. Maintaining bone health in this population is extremely important, especially in the elderly as there is typically has a decline in bone mass with age. (level of evidence 2a)

Flexibility and strengthening exercises

These can help improve the individuals overall physical function and postural control. Improving postural control is important to reduce the risk for falls. Falls often result in fractures in frail individuals. Balance exercises are also important to incorporate to further reduce the risk of falls. (level of evidence 1b)

Postural exercises

These are crucial to prevent structural changes that often accompany osteoporosis, such as thoracic kyphosis. Every osteoporosis program should include extension exercises; chin tucks, scapular retractions, thoracic extensions, and hip extensions. Strengthening the extensor muscles will promote improved posture and improved balance. Flexion exercises are CONTRAINDICATED. Anterior compressive forces to the vertebra can contribute to compression fractures. (level of evidence 5)

Back pain

Physical therapist may treat patients with osteoporosis for back pain. Agility training, resistance training, and stretching have all been shown to decrease back pain and its related disabilities in this population. (level of evidence 1b)

High intensity training

Research highly supports high intensity training in the prevention of bone lost for women in menopausal years and early stage post menopausal. High intensity training would include body-weight and resistive exercises at a high intensity, similar to circuit training. (level of evidence 1a) Most of these studies have been performed on individuals who have NOT been diagnosed with osteoporosis. This type of training is often contraindicated for individuals with low bone mass.

A Cochrane review has been completed to determine the best exercise for prevention and treatment of osteoporosis. The population was healthy post menopausal females, age 45- 70. Duration of the intervention was at the least ten months, several lasting over a year. The majority of the studies has a frequency of 2- 3 days per week. The results were that combination of exercise promotes greatest improvements in bone mass at the spine, wards triangle, and the femoral trochanter. Dynamic weight-bearing, high force exercise results with greatest improvements at the femoral neck and moderate results at the femoral trochanter. Dynamic weight-bearing, low force exercise had moderate positive effects at the spine. Non-weight-bearing, high force exercise were shown to have moderate effects at the femoral neck. (level of evidence 1a)

Clinical Considerations

Metabolic bone diseases results in impaired healing rates, therefore should be considered when determining prognosis. (level of evidence 5)

Manipulations: A strong precaution should be taken before performing manual techniques such as manipulations or joint assessments that may increase an individuals risk for fractures, especially in the spine. Further studies need to be conducted to determine clinical guidelines for manipulation in osteoporotic individuals. (level of evidence 4c)

Body Weight Supported Treadmill Training: It is contraindicated to use body weight supported treadmill training with individuals who have severe osteoporosis or lower extremity, pelvic, or rib fracture. Severe osteoporosis is considered a T-score greater than 2.5. (level of evidence 1a) (guideline withdrawn)

Practice Patterns: (level of evidence 5)

• 4A: Primary Prevention/ Risk Reduction for Skeletal Demineralization
• 4B: Impaired Posture
• 4C: Impaired Muscle Performance
• 4F: Impaired Joint Mobility, Motor Function, Muscle Performance, Range of Motion, and Reflex Integrity Associated with Spinal Disorder
• 4G: Impaired Joint Mobility, Muscle Performance, and Range of Motion Associated with Fracture
  

Dietary Management 

Diet has a direct correlation to bone growth and as we age we may not be absorbing the adequate amount of calcium. By including a variety of calcium-rich foods, such as milk, cheese, almonds, broccoli, and cauliflower you can make sure that you are getting the amount of calcium that you need. It is also recommended that a person with osteoporosis should not have a high-protein diet. When the kidneys flush out excess protein they also flush out calcium. Caffeine is also known to inhibit calcium absorption so you should limit your caffeine intake to the equivalent of 3 cups of coffee a day. While most leafy green vegetables are a great addition to the diet of someone with osteoporosis it has been shown that oxalate acid that is found in spinach prevents absorption of calcium in the stomach. Kale and other geen vegetables that contain calcium would be better choices.

Vitamin supplements may also be necessary when managing osteoporosis. According to the University of Maryland Medical Center (UMMC), 1,500 milligrams of calcium, taken in 3 doses of 500 milligrams per day, is an effective supplement to strengthen the bones and prevent further bone loss. Other vitamins that are recommended to retain bone strength are vitamins D and K. But be careful not to exceed 1,000 milligrams of vitamin D or 500 micrograms of vitamin K daily. Another helpful addition would be to add 4 grams of fish oils to help increase the amount of calcium that your body absorbs and decrease the amount it loses.

Differential Diagnosis

It is important to ensure the cause of low bone denisty has been properly diagnoised. The treatments will vary greatly.

• Osteomalacia/ Rickets: Osteomalacia is softening of the bones due to a Vitamin D deficiency in adults, which can result in decalcification of the bone, fractures, skeletal deformities, bone pain and muscle weakness. Rickets is a similar condition in children.
• Paget's Disease: Bone is resorbed and formed at an increased rate, which may lead to pain, fractures, deformity, headaches, dizziness, osteoarthritis, spinal stenosis, and increased size of clavicle are a few common presentation.
• Bone Infection
• Pediatric osteogenesis imperfecta
• Cancer: Fractures caused by little or no force often occur due to osteoporosis, but may also be result of bone cancer or metastatic cancer.
• Multiple Myeloma
• Renal osteodystrophy
• Scurvy: Vitamin C deficiency 
  

Case Reports/ Case Studies

The Effects of Whole Body Vibration on Bone Mineral Density for a Person with a Spinal Cord Injury: A Case Study

scholarworks.boisestate.edu/cgi/viewcontent.cgi

Asymmetric lower-limb bone loss after spinal cord injury: Case report

web.ebscohost.com/ehost/pdfviewer/pdfviewer

Resources

National Osteoporosis Foundation http://www.nof.org/

Journal of the American Physical Therapy Association www.physther.org/content/67/7/1100.full.pdf

Cochrane Review onlinelibrary.wiley.com/doi/10.1002/14651858.CD000333.pub2/abstract