The association of radiographically detected vertebral fractures with back pain and function: a prospective study.

BACKGROUND

Vertebral fractures are a hallmark of postmenopausal osteoporosis and an important end point in trials of osteoporosis treatment, but the clinical significance of these fractures remains uncertain.

OBJECTIVE

To determine the association of new vertebral fractures with back pain and back-related functional limitation in older women.

DESIGN

Prospective observational study.

SETTING

Multicenter Study of Osteoporotic Fractures.

PARTICIPANTS

7223 white women aged 65 years and older.

MEASUREMENTS

Lateral spine radiographs were obtained at baseline and at a follow-up examination an average of 3.7 years later. Prevalent and incident radiographic vertebral fractures were assessed by quantitative morphometry. Frequency and severity of back pain, disability in doing six activities involving the back, and days of bed rest and days of limited activity due to back pain were assessed annually by questionnaire during follow-up.

RESULTS

Among women without a vertebral fracture at baseline, those with at least one incident vertebral fracture were more likely to have increased back pain (odds ratio [OR], 2.4 [95% CI, 1.7 to 3.3]) and back disability (OR, 2.6 [CI, 1.9 to 3.7]) and at least 1 day of bed rest due to back pain (OR, 6.7 [CI, 4.4 to 10.2]) and 7 days of limited activity due to back pain per year (OR, 3.8 [CI, 2.7 to 5.0]). Among women with a fracture at baseline, those with an incident vertebral fracture also had a greater risk for increased back pain (OR, 2.0 [CI, 1.4 to 2.8]) and back disability (OR, 2.2 [CI, 1.5 to 3.1]) and at least 1 day of bed rest (OR, 7.9 [CI, 4.9 to 12.9]) and 7 days of limited activity per year (OR, 3.5 [CI, 2.4 to 5.0]). Women with incident fracture had about 10 additional limited-activity days and 1 to 2 days of bed rest per year. New vertebral fractures that did not come to medical attention were associated with increased back pain and functional limitation.

CONCLUSION

New vertebral fractures, even those not recognized clinically, are associated with substantial increases in back pain and functional limitation due to back pain in older white women. Prevention of new vertebral fractures should reduce the burden of back pain and functional limitation in women with vertebral osteoporosis.