What is osteoporosis?

The NIH convened a consensus development conference on osteoporosis in 2000. The consensus definition of osteoporosis is that it is “a skeletal disorder characterized by compromised bone strength predisposing to an increased risk of fracture.” This is a very appropriate working definition that has moved the field forward at an accelerated pace leading to innovative basic and clinical science. However, it will take some time before the emerging technologies become an integral part of day to day clinical practice.

In the meantime, there is a major knowledge gap that leaves many patients with overt clinical manifestations of the disease — fracture and its consequences — unrecognized and, therefore, untreated.

Why is this happening?

Spontaneous fractures related to “compromised bone strength” do occur in the spine but most other osteoporosis related fractures result from some trauma. A long-standing definition of an osteoporosis-related fracture is a fracture resulting from minimal trauma defined as trauma equal to or less than a fall from a standing height. That definition still holds although there is mounting evidence that fractures resulting from even greater trauma (e.g., falling off a step) are also reflective of diminished bone strength. When patients sustain a fracture they most often find themselves in an emergency department where the appropriate correct action is to take care of the fracture and any thoughts of osteoporosis are in the background other than in hip fracture cases. Think of some recent cases of prominent persons with fracture where, to my knowledge, the term osteoporosis has not been used in any media reports.
Too many programs providing DEXA as a clinical service still rely entirely on the T-score to differentiate between osteoporosis (T-score ≤–2.5) and low bone mass (osteopenia with T-score >–2.5). Just this week I read three such reports in which the clinical history clearly stated that the patient has had a fracture but the word osteoporosis is not mentioned. Worse yet are those reports that state that one of the measured lumbar vertebrae was excluded from the analysis because of a fracture but the term osteoporosis is still missing from the report. Several studies, both cross-sectional and prospective, have clearly demonstrated that most osteoporosis-related fractures occur in individuals with a T-score >–2.5. This is not a surprise or an issue with the diagnostic cut-points. There are simply more women in the low bone mass (osteopenia) range than in the osteoporosis T-score range.

This concern about neglecting a diagnosis of osteoporosis in patients with a new fracture is critical because the best predictor of tomorrow’s fracture is yesterday’s fracture. The ED is not the place to consider osteoporosis as a diagnosis — although it wouldn’t hurt and should be simple to implement in the discharge papers. But there is no excuse for not considering osteoporosis as the diagnosis at the first follow up visit either to an orthopedic surgeon or primary care physician.

Not making a diagnosis of osteoporosis in a patient with a minimal trauma fracture and a T-score of –2.1, for example, is the same error as not considering a diagnosis of acute myocardial infarction because the patient does not have documented hyperlipidemia.