Evaluating patients with fragility fractures: Orthopedic surgeons see these patients first

Patient care means evaluation of bone density, determination of underlying cause of osteoporosis, treatment, follow-up of low BMD.

Fragility fractures are defined as fractures that occur from minimal trauma, such as a fall from a standing height or less, or from no identifiable trauma. Despite exciting improvements in fracture management techniques and hardware, fractures — particularly fragility fractures — continue to cause disability, deformity, dependence and even death in a large percentage of our patients. We now understand that adults who suffer a low-energy fracture are special. They are individuals at significant increased risk for future fractures.

This month’s round table explores why fragility fractures are requiring increasing attention from the orthopedic surgeon and provides insights on the work-up of the patients with a fragility fracture.

Laura Tosi, MD
Orthopedics Today Editorial Board Editor,
Pediatrics Section

MODERATOR Laura T. Tosi, MD Associate Professor of Orthopaedic Surgery and Associate Professor of Pediatrics, George Washington University Medical Center Section Chief, Orthopaedic Surgery and Sports Medicine Children's National Medical Center, Editor of Orthopedics Today's Pediatrics Section PARTICIPANTS Olof Johnell, MD, Professor of Medicine, Department of Orthopaedics, Malmo General Hospital, Malmo, Sweden Joseph Lane, MD, Department of Orthopedic Surgery, Hospital for Special Surgery, New York Ann Babbitt, MD, Greater Portland Bone and Joint Specialists, Portland, Ore. Mary L. Bouxsein, PhD, Assistant Professor, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston

Laura L. Tosi, MD: Fractures have always been considered a natural consequence of aging. Dr. Johnell, what has changed?

Olof Johnell, MD: We have new data that are truly compelling. Although investigators have known that there is an increased fracture risk following a fragility fracture for more than a decade, they are just now beginning to understand the details of this relationship. We now recognize that the risk of refracture is two to six times greater for patients with a low-energy fracture at any skeletal site regardless of bone mass. In addition, the presence of both low bone mineral density (BMD) and previous fracture dramatically increase the risk of fracture more than each risk factor alone.

Although no one has a crystal ball to indicate where the next fracture will be, the increased risk of fracture is highest at the same site. A new vertebral fracture is five times more likely, for example, among patients with a history of vertebral fracture. And, the risk of hip fracture for those patients is also doubled relative to patients who have not fractured.

Tosi: Does this mean that a history of a fracture predicts future fractures?

“Taken as a whole, patients with a history of any type of prior fracture have two to four times the chance of another fracture compared to those who have never suffered a fracture.” — Mary L. Bouxsein

Mary L. Bouxsein, PhD: Absolutely, and a fracture at one site is associated with higher risk at other sites, as well. For example, patients with a wrist fracture, a fracture often seen in younger patients, have a 1.5 to threefold increased risk for future hip fracture and a five- to 10-fold increased risk for future vertebral fracture. Likewise, up to half of vertebral fracture patients will suffer an additional vertebral fracture within three years, often before a year has gone by.

Taken as a whole, patients with a history of any type of prior fracture have two to four times the chance of another fracture compared to those who have never suffered a fracture.

Tosi: What is the most common type of fragility fracture?

Ann Babbitt, MD: Vertebral fractures are the most common type of fragility fracture. It is estimated that about 700,000 people suffer vertebral fractures each year. Five percent of 50-year-old women and 25% of 80-year-old women have had at least one vertebral fracture. Unfortunately, only about one-third of vertebral fractures are diagnosed when they occur. The reasons are that patients don’t seek medical attention, x-rays are not ordered, x-rays are incorrectly interpreted or, in some cases, the patients do not have significant symptoms.

And the clinical consequences of vertebral fractures are significant. Besides pain, vertebral fractures cause loss of height, reduced pulmonary function, deformity, disability, decreased quality of life, and a 20% to 35% increased mortality rate. Most important, a single vertebral fracture increases the risk of subsequent vertebral fracture two- to fivefold.

Tosi: Are all low-energy fractures considered to be fragility fractures?

COURTESY OF THE INTERNATIONAL OSTEOPOROSIS FOUNDATION

Johnell: Historically, only vertebral, hip, wrist and humerus fractures were described as fragility fractures. However, more and more studies are finding that adults who fracture at other sites such as the pelvis, proximal humerus, rib, femur and tibial plateau also have low bone density, so the definition of a fragility fracture is definitely expanding.

Tosi: What percentage of fractures seen by an orthopedist are typically fragility fractures?

Johnell: Clearly, the percentage of patients who have fragility fractures will vary with the patient population. However, in a recent review of all fracture patients over age 50 seen in Glasgow, Scotland, only 17.7% of patients had normal bone density at both the hip and spine. Put another way, 82.3% of patients demonstrated osteopenia or osteoporosis on bone density testing at either the hip or spine.

Patients who had fractures typically associated with osteoporosis (hip, wrist, humerus) were most likely to demonstrate classic osteoporosis, but 74% of the patients who had fractures at sites not typically associated with osteoporosis (ankle, hand, foot, other sites) also had low bone density at either the hip or spine. These findings strongly suggest that a history of any low-trauma fracture indicates a need for an evaluation.

Tosi: Are some patients more at risk for refracture than others?

Bouxsein: Definitely. A fragility fracture is especially problematic in younger adults. Although younger patients (those in their 40s, 50s and 60s) have a low probability of sustaining a first fracture, their risk of refracture is much higher than for older people. Thus, secondary preventive strategies must be also be aimed at younger patients, not just the elderly. And this includes men.

Tosi: Are fragility fractures equally important in both men and women?

Joseph Lane, MD: Yes. Although fractures are uncommon in men, we now understand that if a man has a fracture, his risk of refracture is higher than that of a woman of the same age. This appears to be because men who fracture have a much higher probability of having a secondary cause of osteoporosis such as hypogonadism, alcoholism or use of glucocorticoid medication than women do. Ironically, this is good news because if the secondary cause of the osteoporosis can be identified and treated, these individuals can see a significant improvement in their bone quality and reduction in fracture risk.

This is important because although the rate of hip fracture among men is one-third to one-half that among women of similar age, the increased mortality in men suffering a hip fracture is higher than in women.

Tosi: Is it important to initiate therapy quickly?

Johnell: Absolutely. We recently published a study that demonstrates that the risk of fracture is much higher in the immediate post-fracture period than previously recognized. Our findings suggest that for fractures of the shoulder, spine and hip, refracture risk is initially very high and then falls, but not to the level of the general population. The explanation for this transient marked increase in risk has not been worked out, but we suspect that immobilization and deconditioning play a significant role.

Tosi: Dr. Lane, how should these new data on fragility fractures impact how we are treating fragility fractures?

Lane: Unfortunately there is no treatment available that completely prevents repeat fractures. However, the data indicate that it is possible to reduce the risk of a hip fracture by up to 50% and the risk of recurrent vertebral fracture by up to 70% to 90% with medical intervention. And studies have shown that therapeutic agents are most effective for those patients with the highest risk, ie, those with vertebral fractures and low bone density.

The implications of these data are clear: All patients who suffer a fragility fracture need to be evaluated for osteoporosis and offered counseling on preventing future fractures.

Because the orthopedic surgeon is frequently the only physician seen by a patient for care of their fragility fracture, it is essential that orthopedic surgeons help to ensure that their patients receive optimal post-fracture care beyond the treatment of the fracture itself.

Tosi: From a practical standpoint, what does that really mean?

Babbitt: Care of the patient with a fragility fracture necessitates evaluating their bone density and searching for an underlying cause of osteoporosis, followed by treatment and follow-up of the low bone density if it is found. It is essential to ensure that patients have adequate intake of protein, calcium and vitamin D. In addition, many patients will benefit from a fall prevention program.

Whether orthopedic surgeons evaluate and treat fragility fracture patients personally or refer these patients to another clinician for further evaluation, educating fragility fracture patients about the risk of refracture and the need for evaluation and treatment has the potential to significantly improve long-term outcomes.

Tosi: Are there any tools available to assist the patient in understanding the importance of their fracture?

Babbitt: Few patients are aware of the relationship between fractures and osteoporosis. Thus, physicians who involve themselves in fracture care need to do an extraordinary amount of patient education simply to explain why evaluation and treatment are needed. This can be extremely time-consuming.

Fortunately, there is a superb teaching aid available entitled “Once is Enough: A Guide to Preventing Future Fractures.” This document was produced by the National Institutes of Health Osteoporosis and Related Bone Diseases National Resource Center and is available on the Web at www.osteo.org under “fact sheets.” This document provides a superb overview of the need for diagnosis and treatment, as well as a summary of treatment strategies. It is available both in Spanish and English.

Tosi: What are the essential elements of the evaluation of a fragility fracture?

Lane: The evaluation of the patient with a fragility fracture includes conducting a thorough medical history and physical examination, performing routine laboratory tests, getting a bone density measurement and doing a radiographic evaluation.

First, a standard medical history should be obtained, with particular attention paid to age, weight, personal history of fracture, family history of fracture, and risk factors for osteoporosis. It is particularly important to watch out for patients with chronic diseases or on those drug therapies, such as glucocorticoid therapy that are known to increase an individual’s risk for low bone mass and fractures.

A physical examination should be conducted, with emphasis on the spine. Height should be measured and compared with greatest known height to determine height loss. Loss of height is an excellent marker for the presence of vertebral fractures.

Tosi: Should all of our fracture patients have a bone density test?

Lane: Almost all of them should. There are three important reasons to order a bone densitometry exam in the fragility fracture patient. First, it’s important to confirm a diagnosis of osteoporosis and document the severity of bone loss. Second, it will help predict future fracture risk and help the clinician make treatment decisions. Third, it can be a helpful tool for monitoring changes in BMD over time.

“The relative risk of fracture increases progressively with decreases in BMD, approximately doubling with each standard deviation decrease in BMD.” — Olof Johnell

Johnell: Patients with a fragility fracture have an increased risk of future fracture whether they have low bone mass or not. However, BMD measurements are an excellent indicator of bone strength and fracture risk. In fact, a BMD measurement predicts fracture risk better than hypertension predicts the risk of stroke or hypercholesterolemia predicts the risk of myocardial infarction.

The relative risk of fracture increases progressively with decreases in BMD, approximately doubling with each standard deviation decrease in BMD. Although the increased risk of future fracture associated with the presence of a previous fracture is largely independent of the patient’s BMD value, the presence of both low BMD and a previous fracture dramatically increases the risk of fracture more than either risk factor alone.

Thus the bone density exam is a powerful tool for both defining the patient’s risk of future fracture and helping the patient understand the significance of their disease.

Tosi: What is the best technique for measuring bone density?

Lane: Although there are many devices available for osteoporosis screening of the patient who has already had a fracture, a central DXA (dual energy x-ray absorptiometry) is considered the gold standard. Current methods for measuring BMD demonstrate precision errors of the same order of magnitude as natural short-term changes in BMD. Thus it is important to use a technique that has the best possible reproducibility. DXA uses an x-ray source, with short scan times and low radiation dose.

Tosi: Are there some patients who do not require a DXA?

Healthy bone (left) compared to osteoporotic bone (right). COURTESY OF THE INTERNATIONAL OSTEOPOROSIS FOUNDATION

Lane: Given the increasing range of therapeutic options for fragility fracture care, it is essential to monitor response to therapy in younger patients. However, among our older patients, especially those who are over 85 or who have severe spine deformity, laying down for a DXA scan may be impractical. In those cases, most clinicians will initiate treatment without a baseline DXA test.

Tosi: Do men have higher bone density than women?

Bouxsein: The answer is not straightforward. By standard clinical bone densitometry measurements, men have higher BMD values than women. However, this is in large part due to the fact that men have bigger bones than women. If we consider the true volumetric density of the bone material, then most evidence suggests that young men and women have the same volumetric bone density. However, with aging, women may have slightly greater bone loss than men, particularly around the menopausal period. It is not completely clear why women fracture more than men. It may be because they fall down more, or it may be because they have smaller bones that can’t resist the forces exerted on the skeleton during a fall.

Tosi: Does BMD vary according to a patient’s race, as well?

Lane: Typically African-Americans and Latinos have higher BMD than whites, while Asians tend to have slightly lower BMD than whites. This is mainly due to their smaller size. When BMD results are reported in nonwhite patients, it is important to know whether the T and Z scores are based on comparison to whites or to the patient’s racial group.

Tosi: What if the DXA report comes back as normal in a fragility fracture patient? Does this mean that the patient has normal bone and is not at increased risk for future fracture?

Bouxsein: Unfortunately, no. We now understand that bone density as measured by DXA is only one marker of bone strength. Patients who suffer a fragility fracture, even if they have normal bone density, are at increased risk for future fractures. Here it is the history of fracture and the severity of that fracture, as well, that are the best predictors of future fracture, not the DXA readout.

Tosi: Is ultrasound testing of bone density helpful in the fragility fracture patient?

Lane: Ultrasound is excellent for predicting fracture risk and for initiating discussions about lifestyle changes and for basic education about osteoporosis. Thus, it is frequently used as an initial osteoporosis-screening tool. However, it is not precise enough to monitor therapy across time. So for the patient who has had a fragility fracture, DXA is the best .

Tosi: What about QCT [quantitative computed tomography]?

Lane: QCT is sold either as add-on software for the standard large CT devices or as small devices for measuring bone density in the extremities. QCT is accurate and uses about the same amount of radiation as mammography or a chest x-ray. It can be very useful in some cases, such as in patients who have an artificially elevated AP spine DXA reading due to arthritic changes or osteophyte formation.

However, it is generally not used for monitoring changes in patients with a history of fragility fracture or on medical therapy because the precision error is about 2% to 4%, while the precision of a DXA is about 1%.

Tosi: Are there any new technologies that will be helpful in diagnosing our fragility fracture patients?

Lane: Traditionally physicians have used lateral spine x-rays to screen for vertebral fractures. However, this is expensive and requires fairly high radiation exposure.

Two new products on the market have made screening for vertebral fractures much easier. Hologic Inc. has added Instant Vertebral Assessment Technology that uses fan-beam technology to its Delphi bone densitometers to create an image of the entire spine and at 1% of standard film radiation dose.

Similarly, GE Lunar has its own Lateral Vertebral Assessment product as an option for its Prodigy Oracle densitometer. Most vertebral fractures are asymptomatic. These devices allow the physician to screen for occult vertebral fracture and thus identify those patients who are at greatest risk for future fracture and initiate preventive measures.

Tosi: What x-ray studies besides the fracture care films should be performed?

Lane: If the patient has a history of back pain, increasing kyphosis or excessive height loss (4 cm) and the DXA technologies described in the previous paragraph are not available, lateral lumbar and thoracic spine radiographs can be used to document the presence of vertebral fractures.

Tosi: Besides a DXA, are there other studies that should be ordered?

Lane: Yes, up to one-third of women and two-thirds of men will be found to have an underlying condition contributing to their bone loss. In women this will most commonly be a history of early ovarian failure, corticosteroid use or excessive thyroid replacement.

In men, this will more likely be hypogonadism, alcoholism, or corticosteroid use.

“There is growing recognition that vitamin D deficiency leading to osteomalacia is also a major contributor to fragility fractures.” — Ann Babbitt

Babbitt: Recommended lab studies include CBC, sedimentation rate, chemistry profile, calcium, phosphorous, alkaline phosphate, TSH, intact PTH, and 25(OH) vitamin D. Many physicians also recommend obtaining a 24-hour urine calcium.

Tosi: Vitamin D deficiency is associated with osteomalacia, not osteoporosis. Why measure vitamin D levels?

Babbitt: There is growing recognition that vitamin D deficiency leading to osteomalacia is also a major contributor to fragility fractures. This has been seen particularly in homebound elderly living in northern latitudes. Treatment with vitamin D supplementation is associated with a significant reduction in hip fractures in the elderly.

Tosi: Are there any other studies that should be performed?

Lane: In the setting of a fragility fracture and low bone density, measurement of bone turnover markers can provide a handle on ongoing bone loss. Bone turnover markers are biochemical markers found in the serum and urine that become elevated when bone turnover is increased.

Although markers of both bone resorption and bone formation are available, the most widely used marker is a bone resorption marker of Type I collagen called urine N-telopeptide or Ntx. In a patient with a history of fragility fracture and low bone density, the absolute risk of another fracture rises to over 50% if the bone turnover markers are also elevated. They indicate that the patient is losing bone at a rate well beyond normal.