Osteoporotic Fragility Fractures

"Medical Journeys" is a set of clinical resources reviewed by doctors, meant for physicians and other healthcare professionals as well as the patients they serve. Each episode of this 12-part journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.

Osteoporosis currently causes more than 8.9 million fractures annually -- meaning there is a fragility fracture every 3 seconds. Worldwide, an estimated 158 million people age 50 and older are at high risk of osteoporotic fragility fractures.

The primary objective of preventive and active care for this widespread condition is avoiding bone fractures and the resulting pain, disability, costly hospitalizations, and even death risk.

"Although osteoporosis is very common, it is often asymptomatic and therefore under-diagnosed," said Jennifer K. Kelly, DO, director of the Metabolic Bone Program at the University of Vermont Medical Center in South Burlington. "It's important to diagnose it before a patient suffers the pain and disability of fracture and is at high risk for another."

Anna N. Miller, MD, professor of Orthopedic Surgery and vice chair of Faculty Affairs, Orthopaedic Surgery, in the Division of Trauma Surgery at Washington University School of Medicine in St. Louis, noted that osteoporosis is silent. "It's not like heart disease where you may have warning chest pain, or lung disease where you have breathing difficulties, so people don't go to primary care with symptoms," she explained. "Many people at risk don't realize they have osteoporosis before they fracture a bone unless it's picked up incidentally during imaging for some other condition."

Fracture Risk Assessment

Fracture prevention begins with routine assessment or screening of patients, according to practice guidelines from the Bone Health and Osteoporosis Foundation. The guidelines make the following clinical recommendations:

• Investigate any broken bone in adulthood at any age as suspicious for osteoporosis, but especially low-trauma fractures

• Measure a patient's height annually: height loss may indicate vertebral deformities of compression fractures

• Record a patient's history of falls: recurrent falls are an additional risk for fracture

• Test bone mineral density -- ideally at the same high-quality facility each time, in the following groups: (1) Women age 65 and older and men 70 and older; (2) Postmenopausal women and men age 50-69, according to a heightened risk profile based on family history, glucocorticoid use, and tobacco and alcohol use; and (3) Postmenopausal women as well as men age 50 and older with a history of adult fracture

In addition, the guidelines note, after an incident fracture the risk of another fracture is highest in the next 2 years, and although fracture risk decreases progressively thereafter, it remains higher than at baseline for at least 25 years.

FRAX: Fracture Risk Assessment

The FRAX fracture risk assessment tool has been incorporated into many guidelines and into bone density interpretation reports. The tool calculates the 10-year probability of a fracture by screening patients for the following risk factors: age, sex, weight, height, previous fracture, and whether either parent had a hip fracture.

FRAX also factors in current smoking, glucocorticoid use, rheumatoid arthritis, other disorders associated with osteoporosis, excessive alcohol consumption, and, of course, bone mineral density. FRAX can assess fracture risk based on clinical parameters alone -- i.e., without a bone density test.

"FRAX is helpful but not perfect," Kelly cautioned. "Even patients with acceptable T-scores can have fractures, and FRAX helps with assessing risk." (T-scores compare an individual's bone density with the average bone density of young healthy adults of the same gender, expressed in standard deviations above and below the average.) "But, FRAX does not take all risk factors, such as falls or type 2 diabetes, into account."

A new version of FRAX is expected to be released soon with a more comprehensive list of parameters.

Miller noted that FRAX is better at identifying those who are not at risk for fracture than those who are. "The best predictor of another fracture is having had a first one," she said.

Imminent Fracture Risk

Establishing imminent fracture risk is central to categorizing patients at very high risk and choosing appropriate therapy, according to Juliet Compston, MD, of Cambridge Biomedical Campus in the U.K., and Matthew Drake, MD, PhD, of the Mayo Clinic in Rochester, Minnesota, who wrote a perspective article on the topic in the Journal of Bone and Mineral Research.

They note that in terms of preventing imminent fracture, some guidelines now recommend bone anabolic agents as the initial therapy of choice for this population.

Here again, FRAX falls short. "In its present form, FRAX does not capture aspects of fracture history required to distinguish individuals at high fracture risk from those at very high risk," Compston and Drake said. "The recency, site, and number of previous fractures are critical drivers of very high vulnerability."

In particular, a recent hip or clinical vertebral fracture indicates very high imminent fracture risk, and other important criteria include a history of multiple fractures, low bone mineral density, and a high risk of falls.

The recommendation for initial treatment with a bone anabolic agent in very high-risk women is mainly based on two studies in postmenopausal women with severe osteoporosis. Comparing the anabolic teriparatide (Forteo) with the bisphosphonate risedronate (Actonel), the VERO study found a significantly lower risk of vertebral and clinical fractures in the teriparatide group after 24 months of treatment.

In the ARCH study, 12 months of romosozumab (Evenity) followed by 12 months of the bisphosphonate alendronate (Fosamax) was associated with a significantly lower risk of vertebral, clinical, non-vertebral, and hip fractures versus 24 months of alendronate alone. There was also a nonsignificant trend toward fewer non-vertebral fractures in teriparatide-treated women.

Sites of Fracture

According to the American Academy of Orthopaedic Surgeons, the earliest and most frequent site of fragility fractures is the spine. Although not all vertebral compression fractures are due to osteoporosis, these occur an estimated 1.5 million times each year in the U.S. They typically affect the front part of the vertebral body and are almost twice as common as other fractures linked to osteoporosis, such as broken hips and wrists. These compression fractures most commonly occur in vertebrae at the thoracolumbar junction, as well as slightly above or below it.

Multiple fractures in the spine can lead to loss of height and the stooped posture of kyphosis (still sometimes called "dowager's hump"). Preventing an early vertebral fracture is crucial since this can lead to long-term back pain, reduced mobility, respiratory problems, loss of appetite, constipation, gastrointestinal pain, and nerve damage that results in numbness and swelling.

Women with the most severe vertebral fractures are the most likely to incur further fractures, with as much as 3.4 times the risk of hip fracture, and 12.6 times the risk of new vertebral fractures. Almost 20% of women will experience another fracture within a year of a vertebral fracture.

"Yet many patients will not even realize they have a vertebral fracture," said Kelly.

The prevalence of vertebral fractures increases steadily with age, ranging from 20% for a 50-year-old postmenopausal woman to 64.5% for older women. The majority of vertebral fractures are not connected with severe trauma, and only one in three is diagnosed clinically -- i.e., when a patient presents with acute pain and an x-ray is performed.

But fragility fractures are also common in the femur, distal radius, cubitus, proximal humerus, and humerus. Some of these fractures are often treated without surgery, but still indicate a high risk for additional fractures, Miller noted.

Nonsurgical Treatment of Spine Fractures

Fortunately, the pain from most vertebral compression fractures improves within 3 months without specific treatment or repair. Simple measures such as a short period of rest and limited use of pain medications are often all that is required. In some cases, patients may wear a back brace to restrict movement and allow the compression fracture to heal.

It is important to note that after pain improved (healing), the bone does not reform into its original rectangular shape, although it is at risk to collapse further.

Surgical Treatment of Spine Fractures

Cementing fractured vertebrae can reduce pain, but may destabilize the vertebrae around them. So while this can alleviate immediate pain, it may not be beneficial in the long term; most of these injuries are therefore left to heal on their own. If severe pain does not respond to rest and medications, vertebral augmentation procedures may be an option.

• Kyphoplasty: A needle is inserted into the fractured vertebra under x-ray guidance. A balloon is then inserted via an inflatable bone tamp through the needle and once inflated, restores the original height and shape of the disc. When removed, the tamp leaves a cavity that is filled with medical-grade bone cement to strengthen the vertebra and reduce pain. Kyphoplasty can be performed using general or local anesthesia, and after surgery patients can go back to all their normal activities of daily living soon.

• Vertebroplasty: Medical-grade cement is directly inserted into the narrowed vertebra, and patients are advised to return to their normal day-to-day activities soon.

• Outcomes: The benefit of vertebroplasty is often very short term, while kyphoplasty may increase function and decrease pain more quickly than nonoperative treatment. However, both procedures have received mixed reviews, since cementing may destabilize contiguous healthy vertebrae. "Not only is one technique not perceived as better than the other, but to a certain extent, both are going out of favor," Miller said. "The cement used is much thicker than vertebral bone and therefore there is concern it may increase the risk of adjacent fractures."

Hip Fractures

Nearly 75% of hip fractures occur in women, and in terms of severe morbidity and mortality, these fractures are the riskiest. "There's a mortality risk of at least 20% in the first year after a hip fracture, and mortality risk is even worse for men, who are less likely than women to be screened early for bone density," Kelly said

Miller noted that there is a 10% risk of death, even in the first month, and as for the greater mortality for men, she said, "since men are less susceptible to osteoporosis than women, by the time a man actually fractures his hip, his overall heath may already have deteriorated more than a woman's."

Hip fractures require surgery. "Those in the proximal femur, the head, or the neck will usually need a hip replacement," Miller noted, adding that if the break is farther down, it can be repaired with cementing, screws, plates, and rods.

Other fractures such as those of the wrist may need only a cast.

Preventing Falls

Apart from bone-enhancing medications, diet, and supplements, it's important to reduce the chance of falls. This can be done by altering daily and recreational activities, as needed, changing to slip-proof footwear, and reorganizing the living space to improve lighting, ease movement, and remove obstacles as well as loose rugs and slippery flooring.

The Future

On the horizon is the identification of new risk factors for fracture beyond bone mineral density, said Kelly. "In addition, screening tools like incidental CT scanning will help identify patients earlier, and artificial intelligence will be used to define levels of fracture risk."

In the meantime, said Miller, "the main thing to remember is that a serious broken bone like an osteoporotic hip fracture can have as high a mortality rate as heart disease. But osteoporosis is silent. Primary care doctors need to keep this in mind."

Read previous installments in this series:

Part 1: New Insights Into the Complex Biology of Osteoporosis

Part 2: The Latest on Osteoporosis Treatment and Diagnosis