Association of femoral bone mineral density with lumbar vertebral fractures in patients with ankylosing spondylitis / 中国组织工程研究

ABSTRACT

OBJECTIVE: Previous opinions consider the secondary diffuse osteoporosis as the very cause of vertebral fractures in patients with ankylosing spondylitis (AS). However, recent studies on bone mineral density (BMD) and vertebral fractures in AS patients reveal that there is no relation between the two. This article aims at investigating the association of lumbar vertebral fractures with clinical, laboratory, and imaging indexes in AS patients.METHODS: A contrast observation was performed between 65 AS patients and 62 healthy physical examinees, whose lumbar vertebral plain radiographs were taken for checking vertebral fractures. Disease activity evaluation indexes included C-reactive protein, erythrocyte sedimentation rate, finger-to-ground distance, Schobar's index score, Bath AS radiology index (BASRI) and syndesmophyte score. Dual energy X-ray absorptiometry technique was used to measure BMD levels of lumbar vertebras and femurs.RESULTS: Out of the total 65 AS patients, 10 ones (15.4%) had lumbar vertebral fractures, with 4 ones with wedge deformities and the other 6 ones with biconcave deformities. BMD levels of Lumbar vertebras and femurs in AS patients were significantly lower than those in controls (P < 0.01). There were significant differences in Schober's index scores, finger-to-ground distance scores, Bath scores, syndesmophyta scores and intertrochanter BMD values between AS patients with and without vertebral fractures (P < 0.01 ). Multiple logistic regression analyses revealed that intertrochanter BMD values were independently associated with lumbar vertebral fractures in AS patients (P =0.043).CONCLUSION: There is a correlation between low femoral BMD levels and the risk of lumbar vertebral fractures in patients with AS, especially at the intertrochanter area.