DXA scanning in women over 50 years with distal forearm fracture shows osteoporosis is infrequent until age 65 years.

AIMS

Women with distal forearm fracture (DFF) may have low bone mineral density (BMD) and merit Dual Energy Xray (DXA) scanning. However patient age at fracture and the database for 'healthy' subjects may influence how many have osteoporosis and require DXA scans. Osteoporosis prevalence in DFF patients by age was investigated using local or nHanes III databases for BMD.

METHODS

A total of 186 women over 50 years consecutively referred with DFF over 1 year were audited without exclusion criteria. BMD of L2-4 and femoral neck (Hologic QDR4500A) was measured and T- and Z-scores calculated from a local database or nHanes III.

RESULTS

Of 90 patients aged 50-64 years, 21.1% had femoral neck T-score < -2.5 and 7.7% < -3.0 (local) and 8.8% and 4.4% respectively (nHanes III). Patients aged 65-74 years (n = 61) included 19.7% with T-score < -2.5 (nHanes III = 10%). 41.2% (nHanes III = 28.6%) of patients > 75 years had femoral neck osteoporosis. Including patients with spine T < -2.5 increased the proportion to 31.1% (50-64 years) and 34.4% (65-74 years) with no extra over 75 years. Weight predicted low BMD ineffectively (area under ROC = 70%).

CONCLUSION

Osteoporosis is infrequent in women with DFF below 65 years. As fracture prevention treatment yields significant fracture reduction only in patients with T-score < -2.5, DXA scanning below 65 years is not justified. After 65 years scanning is justified at all ages, as even in the elderly patients osteoporosis is present in < 50% of patients with DFF. Using nHanes III limits the number of DFF patients warranting treatment. Low body weight is unreliable for identifying osteoporosis.