Post-Menopausal Vertebral Osteoporosis: Can Dual Energy X-Ray Absorptiometry Forearm Bone Density Substitute for Axial Measurements?

Abstract

This study compared measurements of BMD using dual energy X-ray absorptiometry (DXA) at three sites in the nondominant forearm (ultradistal, distal one-third and a mid-region between these two), the lumbar spine (L1-L4) and the proximal femur (femoral neck, trochanter and Ward's triangle) for the evaluation of vertebral osteoporosis. Studies were performed on 100 normal women aged 29-69 yr (average 52 yr) and 63 osteoporotic women age 48-75 yr (average 66 yr) using the Hologic QDR-1000. Precision values of < 1% were obtained in both normal and osteoporotic women at both forearm and axial sites. Z-scores for the osteoporotics [Z = (mean BMD normal--mean abnormal)/S.D.] were--2.02 lumbar spine, -1.96 femoral neck, -1.79 ultradistal forearm, -1.73 mid region and -1.66 distal one-third forearm. Receiver operating characteristic curves showed that the lumbar spine and femoral neck equally discriminated between normals and osteoporotics with a 95% area under each curve, significantly greater values than those for the forearm which were 87% ultradistal, 89% mid forearm and 86% distal one-third forearm. Fracture thresholds, defined as the 90th centile of BMD for osteoporotic patients, were 1 S.D. below the normal mean for lumbar spine and femoral neck but equal to the mean for ultradistal, 0.6 S.D. below mean for mid region and 0.3 S.D. below mean for distal one-third region. We conclude that for the discrimination of normals and osteoporotic women the three forearm sites are comparable. However, both lumbar spine and proximal femur BMD are superior to all forearm sites.

Patient responses to an integrated service, initiated by community pharmacists, for the prevention of osteoporosis

“…Whereas this service may be of benefit to consumers, 16,17 its value remains unclear as a diagnostic tool because of the uncertainty about the accuracy of the technology used and the bone site chosen. However, both quantitative ultrasound and DEXA appear to predict fracture risk equally well 23,24 and as a preliminary screening tool, combined with a questionnaire and referral for follow-up, plus central BMD testing if necessary, peripheral BMD testing in the pharmacy may have some merit.…”

Quantitative Bone Mineral Assessment at the Forearm: A Review

“…The mass of bone increases during early adulthood until it reaches the so-called peak bone mass value at an age of about 30 years. When the peak bone mass is reached the values remain stable with age and begin to decrease at the age of about 40 years [2,63] or [54]; b [112]; c [5]; d [4]; e [115]; f [2]; g [114]; h [27]; i [46]; j [49]; k [40]; l [66]; m [119]; n [113]; o [120]; p [102]; q [57]; r [81]; s [82]. even earlier [64].…”

“…In cross-sectional studies vertebral fractures have been associated with decreased BMD at the distal radius [7,66,93,113] while measurements at the shaft site have revealed conflicting results [113,114]. SXA of the middistal region of the non-dominant forearm has demonstrated diagnostic ability comparable to antero-posterior and lateral lumbar spine DXA for the detection of radiographically confirmed fractures of the lumbar vertebrae [115].…”

Bone Mineral Density and Bone Loss Measured at the Radius to Predict the Risk of Nonspinal Osteoporotic Fracture

“…The pros and cons of measurement sites have been evaluated accurately and the diagnostic sensitivity of peripheral sites have been debated deeply, being of interest not only for BMD but also for ultrasound quantitative measurement of bone. Although forearm BMD has been found to predict spine and not spine fractures, (9–11) it is particularly useful in predicting wrist fractures (12) but less sensitive than spine and hip BMD in predicting vertebral (5) and proximal femur (8) osteoporotic fractures. Furthermore, the ability of forearm BMD to identify the risk in elderly people is debatable; it has been proven by some authors and confuted by others (1, 2, 13) .…”