AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

Osteoporosis is the most common metabolic bone disease and represents an increasingly serious problem, particularly as the population ages. It has been most commonly recognized in elderly white women, although it does occur in both sexes, all races, and all age groups.

Osteoporosis is defined by the World Health Organization as a T-score of -2.5. T-score is the value compared to control subjects who are at their peak bone mineral density, while Z-score reflects a value compared to patients matched for age and sex.^{1, 2, 3, 4}

Osteoporosis can result in devastating physical, psychosocial, and economic consequences. Despite its adverse effects, it is a condition that is often overlooked and undertreated, in large part because it is a clinically silent disease until it manifests in the form of fracture.

Related eMedicine topics:
Hip Fracture
Idiopathic Scoliosis
Intertrochanteric Hip Fractures
Subtrochanteric Hip Fractures
Vertebroplasty and Kyphoplasty, Percutaneous

Related Medscape topics:
Resource Center  Arthritis
Resource Center  Fracture
Resource Center  Geriatrics
Resource Center  Osteoporosis
CME/CE National Osteoporosis Foundation Issues Guidelines for Osteoporosis Management
CME MORES May Help Identify Men at Risk for Osteoporosis
CME Update in Osteoporosis and Osteoarthritis

Pathophysiology

Osteoporosis is a condition in which bone mass is low and microarchitectural deterioration of bone tissue occurs, leading to bone fragility and an increased risk of fracture. Homeostasis of bone, a living tissue, is maintained by the osteoclast, which is responsible for bone resorption, and the osteoblast, which is responsible for bone formation. Increased bone resorption or decreased bone formation may result in osteoporosis. Osteoporosis can be caused both by a failure to build bone and reach peak bone mass as a young adult and by bone loss later in life.

Accelerated bone loss can occur in perimenopausal women and elderly men and women and can occur secondary to various disease states and medications. Osteoporotic fractures can result both from low-energy trauma, such as falls from a sitting or standing position, and from high-energy trauma, such as a pedestrian struck in a motor vehicle accident. Fragility fractures, which occur secondary to low-energy trauma, characterize osteoporosis.

Frequency

United States

Currently, 10 million Americans have osteoporosis. Another 34 million have low bone mass, which leaves them at increased risk for osteoporosis. Each year in the United States, 1.5 million osteoporotic fractures occur. Of these, 700,000 occur in the spine, 300,000 occur in the hip, and 200,000 occur in the wrist. The remainder of fractures occur at other sites in the body.

International

In Europe, the United States, and Japan, an estimated 75 million people have osteoporosis.

Mortality/Morbidity

Patients who have sustained one osteoporotic fracture are at increased risk for developing additional osteoporotic fractures.⁵ For example, the presence of at least one vertebral fracture results in a 5-fold increased risk of developing another vertebral fracture. Patients with previous hip fracture have a 2- to 10-fold increased risk of sustaining a second hip fracture. In addition, patients with ankle, knee, olecranon, and lumbar spine fractures have a 1.5-, 3.5-, 4.1-, and 4.8-fold increased risk of subsequent hip fracture, respectively.

• Vertebral compression fractures are associated with increased morbidity and mortality rates (see Image 1). Kado et al⁶ demonstrated that women with one or more fractures had a 1.23-fold increased age-adjusted mortality rate, while women with 5 or more vertebral fractures had a 2.3-fold increased age-adjusted mortality rate. Furthermore, mortality rate is correlated with number of vertebral fractures, with 19 per 1000 woman-years in women with no fracture and 44 per 1000 woman-years in women with 5 or more fractures. Vertebral fractures were related to risk of subsequent cancer and pulmonary death, and severe kyphosis was further correlated with pulmonary deaths.
• Hip fractures are also associated with significantly increased morbidity and mortality rates. In the year following hip fracture, mortality rates can be as high as 20%. Men have higher mortality rates following hip fracture than do women. Furthermore, of all patients with hip fracture, approximately 20% require long-term nursing care. Approximately 50% of previously independent individuals become partially dependent, and one third become completely dependent.⁷

Race

Non-Hispanic white women and Asian women are at increased risk for osteoporosis. An estimated one half of all hip fractures will occur in Asia in the next century. Twenty percent of non-Hispanic white and Asian women aged 50 years or older are estimated to have osteoporosis, and 52% have low bone mass. Ten percent of Hispanic women aged 50 years or older are estimated to have osteoporosis, and 49% have low bone mass. Five percent of non-Hispanic black women older than 50 years are estimated to have osteoporosis, and 35% have low bone mass. Seven percent of non-Hispanic white and Asian men aged 50 years or older have osteoporosis, and 35% have low bone mass. Four percent of non-Hispanic black men aged 50 years or older have osteoporosis, and 19% have low bone mass. Three percent of Hispanic men aged 50 years or older have osteoporosis, and 23% have low bone mass.^{8, 9, 10}

Sex

Of all patients with osteoporosis in the United States, 80% are women and 20% are men. Fifty percent of all women and 25% of all men older than 50 years experience an osteoporosis-related fracture in their lifetime.

Age

Risk for osteoporosis increases with age. Bone mineral density declines with age, and fractures become more prevalent as age increases.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

Patients with acute insufficiency fractures may report a history of minimal or no trauma resulting in pain. They may report a fall from a standing or sitting position. Patients with compression fractures resulting in thoracic kyphosis may report iliocostal friction with associated abdominal protrusion, decreased tolerance for oral intake, and breathing difficulties. Patients with hip, pelvic, or sacral fractures may report pain that is worsened with weightbearing.

• Multiple risk factors exist for osteoporosis, and a thorough history should be obtained to screen for and identify the presence of these risk factors. The National Osteoporosis Foundation has categorized these risk factors into nonmodifiable and modifiable risk factors. Nonmodifiable risk factors include personal history of fracture as an adult, history of fracture in a first-degree relative, white race, advanced age, female sex, dementia, and poor health/fragility. Potentially modifiable risk factors include current cigarette smoking, low body weight (<127 lb), estrogen deficiency such as that caused by early menopause (age <45 y) or bilateral ovariectomy and prolonged premenopausal amenorrhea (>1 y), low lifelong calcium intake, alcoholism,¹¹ impaired eyesight despite adequate correction, recurrent falls, inadequate physical activity, and poor health or frailty.
• Secondary osteoporosis may be attributed to many diseases and drug states. Diseases associated with an increased risk of osteoporosis include hyperparathyroidism, rheumatoid arthritis, sarcoidosis, thalassemia, idiopathic scoliosis, multiple myeloma, and thyrotoxicosis. Drugs associated with osteoporosis include lithium, anticonvulsants (such as Dilantin), excessive alcohol use, excessive thyroxine, heparin, glucocorticosteroids, and cytotoxic drugs.
• Patients with osteoporosis may report lactose intolerance and celiac sprue. Celiac sprue has been shown to be associated with osteoporosis in approximately 5% of cases.

Physical

Physical examination of the patient with osteoporosis may elicit pain, or the patient may be pain free. Thoracic kyphosis may be present secondary to vertebral compression fractures, a dowager hump, and a history of loss of height. Patients may have an associated scoliosis. Patients with acute vertebral fractures may have percussion and/or palpation tenderness over the involved vertebrae. Other related findings may include the following:

• Hip fractures: Patients with hip fractures may have severe pain with ambulation. A flexion in abduction and external rotation (faber) hip joint test may reveal limited range of motion with end range pain.
• Pubic and sacral fractures: Patients with pubic and sacral fractures may report marked pain with ambulation and tenderness to palpation, percussion, or both. Furthermore, patients with sacral fractures may have pain with physical examination techniques used to assess the sacroiliac joint, such as the faber, Gaenslen, or squish test.
• Fractures in other parts of the body: Fractures in other parts of the body, including the distal radius and humerus, are typically painful and result in limited range of motion of the involved joint.
• Collagen defects: Patients with osteoporosis may have physical findings consistent with subtle collagen defects. These include a short fifth digit, dentinogenesis imperfecta, hyperlaxity, hearing loss, pes planus, bunions, and blue sclerae.
• Balance difficulties: Patients with osteoporosis are known to have decreased balance, possibly secondary to differences in balance control strategies and sway amplitude. Patients may have difficulty performing tandem gait and performing single limb stance. Poor balance may be noted particularly in patients with severe kyphosis resulting from vertebral compression fractures because their altered center of gravity makes ambulation with a stable base of support difficult for them.¹²

Causes

Osteoporosis may be categorized as having both primary and secondary causes (see History). Primary causes may be further divided into modifiable and nonmodifiable risk factors, while secondary causes are attributed to various disease states and medications.

DIFFERENTIALS

Section 4 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Other Problems to Be Considered

Bony metastases
Multiple myeloma
Primary hyperparathyroidism
Secondary hyperparathyroidism
Osteomalacia
Renal osteodystrophy
Paget disease of bone

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab Studies

• Laboratory studies should be used to assess for underlying causes of osteoporosis.
• • Thyroid-stimulating hormone (TSH): Thyroid dysfunction has been associated with osteoporosis and should, therefore, be ruled out.
  • Intact parathyroid hormone (PTH): An intact PTH level is essential in ruling out hyperparathyroidism. An elevated PTH level may be present in benign familial hypocalciuric hypercalcemia (FHH).
  • Calcium: Calcium levels can reflect underlying disease states. Severe hypercalcemia may reflect underlying malignancy or hyperparathyroidism. In addition, hypocalcemia can contribute to osteoporosis.
  • Twenty-four–hour urinary calcium levels: Urinary calcium levels help to rule out benign FHH, in which urinary calcium levels are low.
  • Celiac sprue panels: Celiac sprue has been associated with approximately 5% of osteoporosis cases.
  • Bone alkaline phosphatase: Bone alkaline phosphatase can be mildly elevated in patients with fractures. In addition, patients with hyperparathyroidism, Paget disease, or osteomalacia can have elevations of bone alkaline phosphatase.
  • Serum and urine immunoelectrophoresis: Serum and urine immunoelectrophoresis are used to exclude the presence of multiple myeloma.
  • Urinary N-telopeptide (NTX): NTX, a marker of bone resorption, should be measured. Elevation of this value (>40 nmol bone collagen equivalent per mmol urinary creatine) indicates a high turnover state. NTX levels may also be used to monitor responses to antiosteoporotic treatments.
  • 25-Hydroxyvitamin D and 1,25-hydroxyvitamin D levels: Abnormalities in 25-hydroxyvitamin D and 1,25-hydroxyvitamin D can reflect liver disease and renal disease such as renal osteodystrophy. Inadequate vitamin D levels can predispose persons to osteoporosis.

Imaging Studies

• Radiographic findings can suggest the presence of osteopenia, or bone loss, although they cannot be used to diagnose osteoporosis. Using the second metacarpal or the metaphysis of a long bone, the sum of the cortical width should be at least equal to the medullary width. Osteopenia is suggested by a sum that is less than the medullary width. In addition, 30-40% bone loss must occur before osteopenia is detected on plain radiography.
• CT scanning may be useful in identifying fractures. CT scanning can be used to identify not only the fracture line but also areas of callus formation and sclerosis, consistent with healing fracture.
• MRI may be useful in identifying fractures. Using fat suppression sequences, marrow edema consistent with fracture may be noted as areas of hypointensity on T1-weighted images in association with corresponding areas of hyperintensity on T2-weighted images. MRI is a very sensitive modality and is believed by some to be the first diagnostic imaging method of choice in the detection of acute fractures, such as sacral fractures.
• Bone scanning may be used to identify the presence of multiple osteoporotic fractures. Areas of increased radioactive tracer uptake represent areas of fracture.

Other Tests

• Bone mineral density studies should be performed with the use of dual energy x-ray absorptiometry (DEXA). DEXA has been shown to be the criterion standard in assessing bone mineral density. In turn, bone mineral density has been shown to be the best indicator of fracture risk. Bone mineral density may also be measured using calcaneal ultrasonography and quantitative CT scanning. DEXA and quantitative CT scanning measure bone mineral density in both the lumbar spine and peripheral sites. Ultrasonography cannot be used for monitoring skeletal changes over time or in evaluating response to therapy.

Procedures

• Bone biopsy: In situations in which an unexplained recurrent fracture exists in the setting of appropriate antiosteoporotic medical treatment, bone biopsy may be performed. Bone biopsy can help to exclude underlying pathologic conditions such as multiple myeloma, which may be responsible for presumed osteoporotic fracture. Typically, iliac crest biopsy is performed either in the minor procedure suite or in the operating room. One may also perform a vertebral body bone biopsy when performing a therapeutic procedure such as kyphoplasty (see Image 2).

TREATMENT

Section 6 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical Care

Medical care includes the administration of adequate calcium, vitamin D, and antiosteoporotic medication such as bisphosphonates¹³ and PTH. In addition, potentially treatable underlying causes of osteoporosis such as hyperparathyroidism and hyperthyroidism should be ruled out or treated if detected.

Surgical Care

Therapeutic procedures include vertebroplasty and kyphoplasty. Vertebroplasty and kyphoplasty are 2 new minimally invasive spine procedures used for the management of painful osteoporotic vertebral compression fractures.

• Vertebroplasty was pioneered in France in the 1980s and was initially used for pathologic fractures. It has been gradually redirected toward osteoporotic vertebral compression fractures. Vertebroplasty was first used for this indication in the United States in the early 1990s.
• • Vertebroplasty involves percutaneous injection of methylmethacrylate into a fractured vertebral body, either through a transpedicular or an extrapedicular route. This procedure can be performed under local or general anesthesia with fluoroscopic assistance.
  • Because this is a continuous insertion into an unprepared bed, a venographic injection is often used to ensure that the needle is not directly aligned with an exiting vein. After verification of appropriate placement, 1-4 mL of a specially prepared methylmethacrylate-containing enhanced radiographic visualization material is then inserted directly with a syringe. One or more levels of the spine can be treated in a single setting.
  • Although the bone cement is injected under pressure, this procedure does not have the potential to correct compression deformities.
  • Extravasation of the cement into the epidural space is a potential complication of this method.
• Kyphoplasty has been used since the mid 1990s and is similar to vertebroplasty, which was pioneered in the 1980s, but a few key differences exist.¹⁴
• • Kyphoplasty involves the use of a balloon inserted into the vertebral body with fluoroscopic guidance. An extrapedicular approach is used in the midthoracic region, while a pedicular route may be used in the thoracolumbar or lumbar spine. The balloon is instilled with radiographic contrast at pressures up to 360 pounds per square inch, which compacts the cancellous bone and re-expands the vertebral body, thus reducing the fracture.
  • The balloon tamp creates a cavity into which polymethylmethacrylate is infiltrated. This acrylic bone cement stabilizes the vertebral body and restores vertebral body height.
  • This procedure has been successful both in reducing the amount of kyphosis and in restoring vertebral body height. It also has successfully reduced pain. Recent studies have shown kyphoplasty to be a safe and minimally invasive spine procedure that results in improved function in elderly patients, allowing them to participate in increased activities, with resulting improvements in independence and quality of life.

Consultations

Consultations can include discussions of nonmedical/nonpharmacologic management of osteoporosis.^{15, 16}

Diet

A diet that includes adequate vitamin D and calcium is essential. Recommendations for patients with osteoporosis include daily dosages of 400-800 IU of vitamin D and 1200-1500 mg of calcium. Good sources of calcium include dairy products, sardines, nuts, sunflower seeds, tofu, vegetables such as turnip greens, and fortified food such as orange juice. Good sources of vitamin D include eggs, liver, butter, fatty fish, and fortified food such as milk and orange juice. Patients who ingest inadequate amounts of vitamin D and calcium should receive oral supplementation. The following conditions can interfere with nutrition:

• Alcohol intake: Excessive alcohol intake can interfere with calcium balance by increasing PTH production and by inhibiting the enzymes that convert inactive vitamin D to its active form. In addition, alcohol can result in hormonal deficiencies and can increase the tendency for falls.
• Anorexia nervosa: Poor nutritional states, such as in anorexia nervosa, an eating disorder, have been strongly associated with bone loss. Nutritional and endocrine factors contribute to bone loss. In particular, low estrogen states, which result from low body weight, result in significant bone loss.

Activity

Physical activity is important in order to improve balance and maintain and build bone mass, muscle strength, and flexibility. Several different exercises have been shown to be beneficial in patients with osteoporosis. ^{17, 18, 19, 20}

• Tai Chi Chuan: Tai Chi Chuan and specific physical therapy programs have been shown to be particularly effective in improving balance and reducing falls.
• • Wolf et al monitored 200 elderly community dwellers who received Tai Chi and computerized balance training. After a 15-week intervention, the authors documented decreased fear of falling responses. In addition, Tai Chi was shown to reduce the risk of multiple falls by 47.5%.²¹
  • Campbell et al monitored 233 elderly community dwellers randomized to an individually tailored physical therapy program in the home compared with usual care and an equal number of social visits. The authors found that after one year, the mean rate of falls was lower in the exercise group than the control group (0.87 versus 1.34, respectively). In addition, after 6 months, subjects in the exercise group had improved balance.
• Balance and strengthening programs: Other types of exercise training programs may also positively impact balance and strength.
• • Carter et al demonstrated that osteoporotic women aged 65-75 years who underwent a 10-week community-based physical activity intervention program improved their static balance, dynamic balance, and knee extension strength, although they did not benefit from a significant reduction in fall risk factors.²²
  • Sinaki and others demonstrated strengthening of the back extensor muscles to reduce kyphosis and decrease the risk of sustaining vertebral compression fractures.^{23, 24}
• Impact exercises: In postmenopausal women, impact exercises can increase bone mineral density in the hip and spine.
• • Chien et al examined the efficacy of a 24-week aerobic exercise program consisting of treadmill walking followed by stepping exercises in osteopenic postmenopausal women aged 48-65 years. Women who exercised had increased bone mineral density in L2-L4 and the femoral neck, as well as improved quadriceps strength, muscular endurance, and peak exercise oxygen consumption (VO₂ max), while values in the control group declined.²⁵
  • Also, Snow et al found increased bone mineral density of the femoral neck, trochanter, and total hip in 18 postmenopausal women (average age 64 y), who wore weighted vests and participated in jumping exercises 3 times per week for 32 weeks of the year over 5 years.²⁶

MEDICATION

Section 7 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

The goals of pharmacotherapy are to reduce morbidity and prevent complications.

Drug Category: Bisphosphonates

These agents inhibit bone resorption via actions on osteoclasts or osteoclast precursors.

Drug Category: Anabolic bone agents

Help to build bone by stimulating osteoblasts.

Drug Category: Calcium and vitamin D supplements

Calcium and vitamin D are essential in order to increase bone density.

Drug Category: Calcitonin analogs

These agents inhibit osteoclastic bone resorption.

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Complications

• Complications resulting from osteoporotic fracture can include chronic pain from vertebral compression fractures and increased morbidity and mortality secondary to vertebral compression fractures and hip fractures. In addition, overall quality of life can be impaired by the presence of these fractures and their consequences, such as immobility.

Prognosis

• Patients with osteoporosis can increase bone mineral density and decrease fracture risk with the appropriate antiosteoporotic medication. In addition, patients can decrease their risk of falls by participating in a multifaceted approach that includes rehabilitation (see Activity) and environmental modifications, among others.

Patient Education

• Patient education is paramount in the treatment of osteoporosis. Many patients are unaware of the serious consequences of osteoporosis and only become concerned when osteoporosis manifests in the form of fracture. Early prevention and treatment are essential in the appropriate management of osteoporosis.
• For excellent patient education resources, visit eMedicine's Bone Health Center. Also, see eMedicine's patient education articles Osteoporosis and Understanding Osteoporosis Medications.

MISCELLANEOUS

Section 9 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• Patients must be made aware of the serious consequences that can arise from osteoporosis, including increased morbidity and mortality. Patients who must receive appropriate medical and nonmedical management of their osteoporosis include those at highest risk, such as patients who have had one osteoporotic fracture.

MULTIMEDIA

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  Osteoporosis. Lateral radiograph demonstrates multiple osteoporotic vertebral compression fractures. Kyphoplasty has been performed at one level.
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Media type:  X-RAY

Media file 2:  Osteoporosis. Lateral radiograph of the patient seen in Image 1 following kyphoplasty performed at 3 additional levels.
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Media type:  X-RAY

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

1. Kanis JA, McCloskey EV, Johansson H, Oden A, Melton LJ 3rd, Khaltaev N. A reference standard for the description of osteoporosis. Bone. Mar 2008;42(3):467-75. Epub 2007 Nov 17. [Medline].
2. Silverman SL. Selecting patients for osteoporosis therapy. Ann N Y Acad Sci. Nov 2007;1117:264-72. [Medline].
3. Czerwiski E, Badurski JE, Marcinowska-Suchowierska E, Osieleniec J. Current understanding of osteoporosis according to the position of the World Health Organization (WHO) and International Osteoporosis Foundation. Ortop Traumatol Rehabil. Jul-Aug 2007;9(4):337-56. Review. [Medline].
4. Kanis JA. Assessment of fracture risk and its application to screening for postmenopausal osteoporosis: synopsis of a WHO report. WHO Study Group. Osteoporos Int. Nov 1994;4(6):368-81. [Medline].
5. Osteoporos Int. Who are candidates for prevention and treatment for osteoporosis?. Osteoporos Int. 1997;7(1):1-6. [Medline].
6. Kado DM, Browner WS, Palermo L. Vertebral fractures and mortality in older women: a prospective study. Study of Osteoporotic Fractures Research Group. Arch Intern Med. Jun 14 1999;159(11):1215-20. [Medline].
7. Trombetti A, Herrmann F, Hoffmeyer P. Survival and potential years of life lost after hip fracture in men and age-matched women. Osteoporos Int. Sep 2002;13(9):731-7. [Medline].
8. Aloia JF, Vaswani A, Yeh JK. Risk for osteoporosis in black women. Calcif Tissue Int. Dec 1996;59(6):415-23. [Medline].
9. Lau EM, Cooper C. The epidemiology of osteoporosis. The oriental perspective in a world context. Clin Orthop. Feb 1996;(323):65-74. [Medline].
10. Lauderdale DS, Jacobsen SJ, Furner SE. Hip fracture incidence among elderly Hispanics. Am J Public Health. Aug 1998;88(8):1245-7. [Medline].
11. Chon KS, Sartoris DJ, Brown SA. Alcoholism-associated spinal and femoral bone loss in abstinent male alcoholics, as measured by dual X-ray absorptiometry. Skeletal Radiol. 1992;21(7):431-6. [Medline].
12. Lynn SG, Sinaki M, Westerlind KC. Balance characteristics of persons with osteoporosis. Arch Phys Med Rehabil. Mar 1997;78(3):273-7. [Medline].
13. Lin JT, Lane JM. Bisphosphonates. J Am Acad Orthop Surg. Jan-Feb 2003;11(1):1-4. [Medline].
14. Ledlie JT, Renfro M. Balloon kyphoplasty: one-year outcomes in vertebral body height restoration, chronic pain, and activity levels. J Neurosurg. Jan 2003;98(1 Suppl):36-42. [Medline].
15. Schwab P, Klein RF. Nonpharmacological approaches to improve bone health and reduce osteoporosis. Curr Opin Rheumatol. Mar 2008;20(2):213-217. [Medline].
16. Lin JT, Lane JM. Nonmedical management of osteoporosis. Curr Opin Rheumatol. Jul 2002;14(4):441-6. [Medline].
17. Iwamoto J, Takeda T, Ichimura S. Effect of exercise training and detraining on bone mineral density in postmenopausal women with osteoporosis. J Orthop Sci. 2001;6(2):128-32. [Medline].
18. Kerschan-Shindl K, Uher E, Kainberger F, et al. Long-term home exercise program: effect in women at high risk of fracture. Arch Phys Med Rehabil. Mar 2000;81(3):319-23. [Medline].
19. Robertson MC, Devlin N, Gardner MM. Effectiveness and economic evaluation of a nurse delivered home exercise programme to prevent falls. 1: Randomised controlled trial. BMJ. Mar 24 2001;322(7288):697-701. [Medline].
20. Walker M, Klentrous P, Chow R, Plyley M. Longitudinal evaluation of supervised versus unsupervised exercise programs for the treatment of osteoporosis. Eur J Appl Physiol. 2000;83:349-355. [Medline].
21. Wolf SL, Barnhart HX, Kutner NG, et al. Reducing frailty and falls in older persons: an investigation of Tai Chi and computerized balance training. Atlanta FICSIT Group. Frailty and Injuries: Cooperative Studies of Intervention Techniques. J Am Geriatr Soc. May 1996;44(5):489-97. [Medline].
22. Carter ND, Khan KM, Petit MA, et al. Results of a 10 week community based strength and balance training programme to reduce fall risk factors: a randomised controlled trial in 65-75 year old women with osteoporosis. Br J Sports Med. Oct 2001;35(5):348-51. [Medline].
23. Sinaki M, Itoi E, Wahner HW. Stronger back muscles reduce the incidence of vertebral fractures: a prospective 10 year follow-up of postmenopausal women. Bone. Jun 2002;30(6):836-41. [Medline].
24. Sinaki M, Itoi E, Rogers JW. Correlation of back extensor strength with thoracic kyphosis and lumbar lordosis in estrogen-deficient women. Am J Phys Med Rehabil. Sep-Oct 1996;75(5):370-4. [Medline].
25. Chien MY, Wu YT, Hsu AT, Yang RS, Lai JS. Efficacy of a 24-week aerobic exercise program for osteopenic postmenopausal women. Calcif Tissue Int. Dec 2000;67(6):443-8. [Medline].
26. Snow CM, Shaw JM, Winters KM. Long-term exercise using weighted vests prevents hip bone loss in postmenopausal women. J Gerontol A Biol Sci Med Sci. Sep 2000;55(9):M489-91. [Medline].

Article Last Updated: Mar 27, 2008