Bone Abstracts

Background: DXA is the gold standard for diagnosis of osteoporosis, however its limitations are well recognised.

Methods: 200 patients who underwent DXA assessment following vertebral fracture were identified. Stratified analyses were undertaken by sex and age band (65 years, 65 to 74 years, ≥75 years). Differences in proportions were assessed using Fishers exact test for sex comparisons, while associations with age band were examined using Pearsons chi squared test and a Cochran Armitage test for trend. Paired within patient comparisons between lumbar spine and hip osteoporosis were performed using McNemars test.

Results: Sex stratification Among females (n 144), 71 (49.3%) met densitometric criteria for osteoporosis at at least one skeletal site, compared with 18 of 56 males (32.1%). Lumbar spine osteoporosis was present in 48 females (33.3%) and 13 males (23.2%), while hip osteoporosis was identified in 57 females (39.6%) and 14 males (25.0%). Females had significantly higher odds of densitometric osteoporosis than males (Fishers exact P 0.039; odds ratio 0.49, 95% CI 0.24, 0.97). Age stratification Densitometric osteoporosis at any site was present in 18 of 41 patients aged under 65 years (43.9%), 22 of 60 aged 65 to 74 years (36.7%) and 49 of 99 aged 75 years or older (49.5%). Hip osteoporosis was most prevalent in those aged 75 years or older (40.4%). Mean age was similar between patients with and without densitometric osteoporosis (74.6 vs 74.2 years). There was no statistically significant association between age band and osteoporosis status (² P 0.29), nor evidence of a linear trend across age categories (P 0.35).

Conclusion: In this audit, DXA identified densitometric osteoporosis in almost half of those assessed. Hip and lumbar spine measurements each detected unique subsets of patients, with neither site demonstrating statistical superiority, supporting the continued use of multi-site DXA assessment in this population. However, more than half of patients with vertebral fracture did not meet densitometric criteria for osteoporosis at any site. Females were significantly more likely than males to meet densitometric criteria for osteoporosis, while age was not independently associated with osteoporosis prevalence in this cohort.