Fracture types that allow a diagnosis of osteoporosis
There was a consensus that for the population under consideration, an individual who experiences a low-trauma hip fracture can be diagnosed with osteoporosis, with or without a BMD test. There was also a consensus that a low-trauma clinical vertebral fracture, proximal humerus fracture, or pelvis fracture is diagnostic of osteoporosis in a person with osteopenia. The incidental finding of a vertebral fracture on a radiograph (a morphometric vertebral fracture) may also be considered as diagnostic of osteoporosis if the clinician has a reason to believe that it is likely to have been the result of low bone mass and reduced bone strength. For example, if an older woman has one or more vertebral deformities discovered on a spine radiograph or through vertebral fracture assessment on a DXA test and cannot recall whether or not she had an episode of severe back pain but has BMD-based osteopenia, the osteoporosis diagnosis can be applied. However, if a 51-year-old man has a chest radiograph that shows a vertebral compression deformity and the patient recalls a bad sports injury at the age of 20 with weeks of severe back pain that gradually resolved and a current BMD shows normal or minimally low T-scores, the diagnosis of osteoporosis should not be made.
Finally, in some instances, a low-trauma distal forearm fracture in a person with osteopenia at the lumbar spine or hip by BMD testing may be considered as diagnostic of osteoporosis. A minority of the members of the working group felt that in the population being considered, any wrist fracture in the setting of osteopenia should be diagnosed as osteoporosis. Their argument is that anyone over 50 years who breaks a wrist regardless of the level of trauma and whose assessment reveals low bone mass has osteoporosis, because weaker bones are more likely to break than stronger bones, and wrist fractures predict future fractures [10, 14]. However, a majority of the working group felt that the circumstances of the wrist fracture must be taken into account, and patient age and the level of low bone mass be considered before labeling the patient as having osteoporosis. For example, if a 50-year-old woman crashes while roller blading sustaining a wrist fracture and has normal or minimally low BMD when that indicated test is performed (T-scores no lower than −1.3, as an example), the diagnosis of osteoporosis is probably not appropriate. However, if a 64-year-old individual with a T-score of −2.2 slips on a curb, falls, and breaks her wrist, the diagnosis might apply, particularly if other risk factors are present. In the case of wrist fracture, the diagnosis may be made in some cases and not in others. Clinician judgment, in the context of the clinician understanding on the definition of osteoporosis, would need to be applied, as often is the case in the real world of clinical practice.
While many other fracture types increase the risk of future fractures , the committee did not feel that all fracture types, beyond those listed here, would necessarily constitute a basis for an osteoporosis diagnosis. Therefore, at this time, we suggest limiting the fracture types for an osteoporosis diagnosis to the hip, spine, proximal humerus, pelvis, and, in some cases, wrist, requiring a BMD test showing osteopenia at the spine or hip in all cases except hip fracture. There was also considerable discussion about the level of trauma that led to the fracture, noting that the classical definition of a “fragility” or “low-trauma” or “low-energy” fracture implies, for example, a fall from standing height. Regardless of the level of trauma, however, current recommendations call for a measurement of BMD in older individuals who sustain a fracture in order to rule in or out the possibility that low bone mass was a contributing factor .
The role of FRAX in making the diagnosis of osteoporosis
FRAX is a World Health Organization-sponsored, country-specific fracture risk assessment tool that combines BMD at the femoral neck (or total hip) with a group of well-validated and weighted clinical risk factors for fracture that are largely independent of BMD . It is based upon epidemiological data from 60,000 women and men studied prospectively to correlate risk factors for fracture with fracture outcomes and then validated in independent cohorts including more than 230,000 patients. It is useful as a way of predicting the risk of hip fracture and major osteoporotic fractures, i.e., clinical spine, hip, proximal humerus, and distal forearm fractures, in previously untreated men and women aged 40–90 years. Its use in the USA allows the assessment of fracture risk in both genders and four ethnic groups and is recommended primarily for individuals with a BMD finding of osteopenia .
There was consensus that for the population under consideration if the 10-year probability of hip fracture is ≥3 % or the 10-year probability of major osteoporotic fracture is ≥20 %, a diagnosis of osteoporosis can be made. These two cut points reflect treatment intervention thresholds in the USA as described in the NOF Clinician’s Guide, based in the case of hip fracture on cost-effectiveness criteria for hip fracture management , and were viewed as a logical basis for making a diagnosis of osteoporosis.
The committee believes that expanding the diagnostic criteria for osteoporosis will assist in properly identifying a greater number of people who are, in fact, at an elevated risk for fracture, thus increasing awareness and encouraging strategies to lower risk, which may or may not include prescription therapy in all cases but would be recommended by current guidelines for most . The efficacy of many of the currently available therapies to lower fracture risk is based upon clinical trials in which entry criteria typically required BMD T-scores of ≤ −2.5 at the spine or hip, not fracture history or FRAX scores. In several studies, vertebral fractures were a part of the entry criteria [17–19], with average T-scores reflecting osteopenia in many cases, and in other cases, FRAX data were applied post hoc to determine the efficacy based upon baseline FRAX scores [20, 21]. Individual decisions regarding treatment interventions with medications intended to lower fracture risk will be necessary, and clinicians are advised to consider whether there is evidence for a treatment effect for each of the various therapies in the absence of a T-score diagnosis of osteoporosis .
The committee also cautions that patients not be overdiagnosed based upon these recommendations. We acknowledge that fractures that occur with a high level of trauma may or may not have been influenced by the level of bone strength, and an evaluation, including BMD testing in most cases, is needed after the fracture to help determine the role that reduced bone strength may have played. Care should be taken to avoid making a diagnosis of osteoporosis if the fractures truly resulted from the severity of the trauma in the presence of fairly normal bones. Conversely, a fracture in an older individual after a fall from standing height is too often blamed on the fall without due consideration of the strength of the bones, and it is our hope that these new criteria will compel a more thoughtful assessment of overall fracture risk, so that underdiagnosis will also be reduced.