Osteoporosis
Osteoporosis, Fracture Prevention and Falls Risk Assessment – Closing the Gap between Treatment Guidelines and Clinical Practice
Yasser El Miedany1 and Mathias Toth2
1. Professor of Rheumatology and Rehabilitation, Ain Shams University and Consultant Rheumatologist, Lead Clinician Metabolic Bone Disease; 2. Consultant Physician, Lead Clinician Falls Management, Darent Valley Hospital
Abstract
Osteoporosis is a common disease that is associated with significant morbidity and mortality, the prevalence of which is expected to increase in an ageing population. We know that bone mineral density (BMD) measurements, while valuable, may not provide sufficient information to enable us to identify all patients at high risk of fracture. Furthermore, earlier studies revealed that approximately one-half of osteoporotic fractures occurred in women with a T-score above -2.5. If our aim is to prevent fractures, it is not acceptable just to wait until women have developed osteoporosis and then start treating them. Our ability to predict the risk of fractures can be improved by adding clinical risk factors that contribute to fracture risk independently of BMD. Combined assessments of clinical risk factors for osteoporosis/BMD measurement and fracture risk probability, as well as falls risk, form the main three factors guiding the decision as to whether to initiate osteoporosis therapy and when to reassess. The ‘risk factors assessment strategy’ approach is the best way to identify individual patients who are at high risk for fracture and this may have important clinical implications for their management. This raises the question as to how this risk stratification can be implemented in clinical practice. This article discusses how risk assessments for osteoporosis, falls and fractures can be handled together in standard clinical practice as three confounders in one equation.
Keywords
Osteoporosis, fracture risk assessment tool (FRAX), falls, dual-energy x-ray absorptiometry, falls risk assessment score (FRAS), osteoporosis and falls risk assessment (OPOFRA)
Disclosure: The authors have no conflicts of interest to declare. Received: 11 July 2010 Accepted: 6 January 2011 Citation: European Musculoskeletal Review, 2011;6(1):14–7 Correspondence: Yasser El Miedany, Darent Valley Hospital, Dartford, DA2 8DA, Kent, UK. E:
yasser_elmiedany@yahoo.com
Results of meta-analyses and epidemiological data revealed that bone mineral density (BMD) measurement, while clearly valuable, may not provide sufficient information to identify all patients at high risk of fracture.1,2
Recent studies have shown that many or most patients in the community with fractures have a baseline BMD above the World Health Organization (WHO) diagnostic threshold T-score of -2.5. In the National Osteoporosis Risk Assessment (NORA) study, using peripheral bone density measurements,3
and in the Study of
Osteoporotic Fractures, using central bone density measurements,4 approximately one-half of osteoporotic fractures occurred in women with a T-score above -2.5. Although the relative risk of fractures was greater in women with T scores of -2.5 or less compared with women with a higher T-score, there were many more women in the higher T-score range. BMD measurement, therefore, is highly specific for fracture risk but poorly sensitive.
The clinical dilemma posed by osteopenia typically arises when BMD tests are ordered for patients who might have some risk factors for osteoporosis treatment, such as a clinically evident low trauma fracture in pre-menopausal women or men under the age of 50, or when it presents in association with other risk factors such as hormone antagonist therapy for breast or prostate cancer. This problem can be mitigated by assessing the patient’s risk factors. The WHO classification of BMD (see Figure 1) applies to
14
The presence of a recent vertebral fracture is a strong risk factor for future fractures of all types. However, the scenario might differ in case the fracture was at the distal radius. Although assessment of BMD at the distal forearm is not routinely carried out, fracture of the distal part of the radius often represents a seminal event in patients at high risk for later hip fracture; this highlights the importance of treatment intervention in this high-risk group. Patients who have sustained a distal radial fracture have nearly twice the relative risk of a future hip fracture,7–9
post-menopausal women and men aged 50 and older, but not to pre-menopausal women, men under the age of 50 or children.5 Z-scores, rather than T-scores, are preferred for reporting BMD in these groups of patients. A Z-score of -2.0 or below can be described as below the expected range for age. Assessment of other risk factors is highly advised before considering any form of osteoporosis therapy in these groups of patients. On the other hand, the presence of a low trauma fragility fracture by itself is sufficient to make a clinical diagnosis of osteoporosis, independently of BMD. The finding that a patient’s T-score is not in the range classified as osteoporosis by the WHO (-2.5 or less) might not be surprising. Studies have shown that about one-half of patients with fragility fractures have T-scores higher than -2.5.2,6
and elderly women with a
distal radial fracture have both site-specific and generalised decreased BMD compared with young adults and age-matched controls.10–13
A study showed that 91% of 106 post-menopausal © TOUCH BRIEFINGS 2011
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