Low bone mineral density, but not epidural steroid injection, is associated with fracture in postmenopausal women with low back pain.

BACKGROUND Therapy with glucocorticoids often results in bone loss and glucocorticoid-induced osteoporosis. However, the relationship between epidural steroid injection (ESI), bone mineral density (BMD), and vertebral fracture remains to be determined. OBJECTIVE To establish a relationship between ESI, BMD, and vertebral fracture in postmenopausal women with low back pain. STUDY DESIGN This study was a retrospective, nonblinded, cross-sectional clinical study. SETTING University-based pain management center. METHODS We reviewed the medical records of postmenopausal women with low back pain who were treated with ESI. A total of 352 postmenopausal women were divided into 2 groups. Group 1 consisted of patients without fracture and Group 2 consisted of those with fractures. The results of BMD measurements, as well as any fragility fractures, the anatomical site involved, and the treatment administered, were also recorded. BMD was measured in the lumbar spine, femoral neck, and total femur after the treatment. RESULTS Of the 352 patients, 218 (62%) had no fractures while 134 (38%) sustained a fracture. The age was significantly higher among patients who sustained fractures, and BMD at the lumbar spine, total femur, and femoral neck regions was significantly lower among patients who sustained fractures. In each region, the prevalence of osteoporosis was significantly higher in patients with fracture than in patients without fracture (all P < 0.05). Age, height, and weight were associated with low BMD. However, our study showed no consistent correlation between BMD and the mean number of ESIs, mean total dose of glucocorticoids, or mean duration of ESIs. LIMITATIONS First, this study is limited by the fact that it was retrospective. Second, the number of cases receiving very frequent, high-dose glucocorticoid injections was very small. CONCLUSIONS Older age and lower BMD were associated with osteoporotic fracture in postmenopausal women treated for low back pain with ESI. The ESIs were not associated with low BMD or fracture.