Elsevier

The Lancet

Volume 359, Issue 9321, 1 June 2002, Pages 1929-1936
The Lancet

Series
Diagnosis of osteoporosis and assessment of fracture risk

https://doi.org/10.1016/S0140-6736(02)08761-5Get rights and content

Summary

The diagnosis of osteoporosis centres on the assessment of bone mineral density (BMD). Osteoporosis is defined as a BMD 2·5 SD or more below the average value for premenopausal women (T score <−2·5 SD). Severe osteoporosis denotes osteoporosis in the presence of one or more fragility fractures. The same absolute value for BMD used in women can be used in men. The recommended site for diagnosis is the proximal femur with dual energy X-ray absorptiometry (DXA). Other sites and validated techniques, however, can be used for fracture prediction. Although hip fracture prediction with BMD alone is at least as good as blood pressure readings to predict stroke, the predictive value of BMD can be enhanced by use of other factors, such as biochemical indices of bone resorption and clinical risk factors. Clinical risk factors that contribute to fracture risk independently of BMD include age, previous fragility fracture, premature menopause, a family history of hip fracture, and the use of oral corticosteroids. In the absence of validated population screening strategies, a case finding strategy is recommended based on the finding of risk factors. Treatment should be considered in individuals subsequently shown to have a high fracture risk. Because of the many techniques available for fracture risk assessment, the 10-year probability of fracture is the desirable measurement to determine intervention thresholds. Many treatments can be provided cost-effectively to men and women if hip fracture probability over 10 years ranges from 2% to 10% dependent on age.

Introduction

As prevalence and awareness of osteoporosis increases, and treatments of proven efficacy become available, the demand for management of patients with the disease will also rise. Such demand will, in turn, require widespread development of facilities for the diagnosis and assessment of osteoporosis. Measurement of bone mineral density (BMD) is the central component of any provision that arises from the internationally agreed definition of osteoporosis: a systemic skeletal disease characterised by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture.1 The diagnosis of osteoporosis thus centres on assessment of bone mass and quality. There are no satisfactory clinical means to assess bone quality. Diagnosis of osteoporosis, therefore, depends on the measurement of skeletal mass.

The clinical significance of osteoporosis rests with the fractures that arise as a consequence of the condition, and their attendant morbidity and mortality. Low bone mass is an important component of the risk of fracture, but other abnormalities arise in the skeleton that contribute to skeletal fragility. Furthermore, various non-skeletal factors, such as the liability to fall, contribute to fracture risk. Thus, ideally, assessment of fracture risk should encompass all these aspects. There is, therefore, a distinction to be made between diagnosis of osteoporosis and assessment of risk, which in turn implies a distinction between diagnostic and intervention thresholds.

Section snippets

Single and dual X-ray absorptiometry

Single and dual X-ray absorptiometry (DXA) are used to assess mineral content of the entire skeleton and that of specific sites, including those most vulnerable to fracture.2 Bone mineral content is the amount of mineral in the specific site scanned and, when divided by the area measured, can be used to derive a value for BMD. Both techniques provide a two-dimensional, areal picture, rather than a true volumetric density. Thus, the size of the bone affects the apparent density, since the

Ultrasonic measurement of bone

Skeletal status in osteoporosis can be measured with quantitative ultrasound methods. The most widely assessed methods are broad-band ultrasound attenuation and speed of sound (or ultrasound velocity) at the heel. Because these techniques do not involve ionising radiation and could provide some information with respect to the structural organisation of bone in addition to bone mass, there is much interest in their use. For reasons outlined below, these techniques cannot be used to diagnose

Computed tomography

Quantitative computed tomography has been applied both to the appendicular skeleton and to the spine.9, 10, 11 Conventional whole body computed tomography scanners need calibration to convert their results into units relevant to BMD. Quantitative computed tomography is most useful in the assessment of cancellous bone density because it provides a measure of true volumetric density, rather than an area-adjusted result (as is the case with DXA). Cancellous bone is more responsive than cortical

Radiography

Osteoporosis can often be diagnosed by looking at simple radiographs, albeit with low sensitivity. Furthermore, there are several characteristic features of osteoporosis that can be seen with this technique, which help in diagnosis or in differential diagnosis. Subclinical vertebral fracture is a strong risk factor for subsequent fractures, for example, both at new vertebral sites and at other sites susceptible to osteoporosis. There is, therefore, great interest in the identification of

Conclusions

The diagnosis of osteoporosis is generally based on assessment of BMD at the proximal femur by DXA. By contrast, intervention thresholds should be based on fracture probability. Several clinical risk factors for fracture with and without BMD allow the more accurate stratification of risk than the use of BMD alone. In the absence of validated screening strategies, a case-finding approach is advocated for individuals with strong risk factors who are referred for BMD assessment. Intervention is

Search strategy

This article is based on review of international publications collected by the author during his time working in the specialty.

References (62)

  • CC Glüer

    Quantitative ultrasound techniques for the assessment of osteoporosis: expert agreement on current status

    J Bone Miner Res

    (1997)
  • EW Gregg et al.

    The epidemiology of quantitative ultrasound: a review of the relationship with bone mass, osteoporosis and fracture risk

    Osteoporos Int

    (1997)
  • RW Porter et al.

    Prediction of hip fractures in elderly women; a prospective study

    BMJ

    (1990)
  • HK Genant et al.

    Qualitative computed tomography of vertebral spongiosa: a sensitive method for detecting early bone loss after oophorectomy

    Ann Intern Med

    (1982)
  • T Lang et al.

    Non-invasive assessment of bone density and structure using computed tomography and magnetic resonance

    Bone

    (1998)
  • P Ruegsegger et al.

    Quantification of bone mineralisation using computed tomography

    Radiology

    (1976)
  • JA Kanis et al.

    An update on the diagnosis and assessment of osteoporosis with densitometry

    Osteoporos Int

    (2000)
  • JP Bonjour et al.

    Bone acquisition in adolescence

  • JA Kanis et al.

    The diagnosis of osteoporosis

    J Bone Miner Res

    (1994)
  • JA Kanis et al.

    Clinical assessment of low bone mass, quality and architecture

    Osteoporos Int

    (1999)
  • JA Kanis et al.

    Long-term risk of osteoporotic fracture in Malmo

    Osteoporos Int

    (2000)
  • ME Arlot et al.

    Apparent pre- and postmenopausal bone loss evaluated by DXA at different skeletal sites in women: the OFELY cohort

    J Bone Miner Res

    (1997)
  • S Grampp et al.

    Comparisons of non-invasive bone mineral measurements in assessing age related loss, fracture discrimination, and diagnostic classification

    J Bone Miner Res

    (1997)
  • D Marshall et al.

    Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures

    BMJ

    (1996)
  • E Orwoll

    Assessing bone density in men

    J Bone Miner Res

    (2000)
  • PL Selby et al.

    Do men and women fracture bones at similar bone densities

    Osteoporos Int

    (2000)
  • M Lunt et al.

    Bone density variation and its effect on risk of vertebral deformity in men and women studied in thirteen European Centres: the EVOS Study

    J Bone Miner Res

    (1997)
  • T Nguyen et al.

    Prediction of osteoporotic fractures by postural instability and bone density

    BMJ

    (1993)
  • LJ Melton et al.

    Bone density and fracture risk in men

    J Bone Miner Res

    (1998)
  • JA Kanis et al.

    Ten year probabilities of osteoporotic fractures according to BMD and diagnostic thresholds

    Osteoporos Int

    (2001)
  • SL Hui et al.

    Age and bone mass as predictors of fracture in a prospective study

    J Clin Invest

    (1988)
  • Cited by (1741)

    View all citing articles on Scopus
    View full text