Accuracy of height loss during prospective monitoring for detection of incident vertebral fractures

Abstract

Vertebral fractures are the most common type of osteoporotic fracture, but more than two-thirds remain undetected. We have examined the relationship between height loss and the development of new vertebral fractures to determine whether there is a height loss threshold that has useful clinical accuracy to detect new fractures. We studied 985 postmenopausal women with osteoporosis in the placebo arms of the Vertebral Efficacy with Risedronate Therapy studies. Height was measured annually for 3 years using a wall-mounted stadiometer. New fractures were determined using quantitative and semi-quantitative radiographic morphometry. The relationship between height loss over three years and the number of new vertebral fractures was: height loss (cm) = 0.95 x number of new vertebral fractures-0.4 cm (r = 0.33). The odds ratio for the development of a new fracture increased up to 20.6 (95% confidence interval, 9.3, 45.8) when height loss was greater than 4.0 cm. At a threshold of > 2.0 cm height loss over 3 years, sensitivity was 35.5% for detecting new vertebral fractures and specificity was 93.6%. These findings show that there is a strong relationship between the amount of height loss and the risk of a new vertebral fracture. While there is no cut-off that can reliably rule in a new fracture, height loss of < or = 2.0 cm over 1-3 years has acceptable accuracy for ruling out an incident fracture.

Goal-Directed Treatment for Osteoporosis: A Progress Report From the ASBMR-NOF Working Group on Goal-Directed Treatment for Osteoporosis

“…(7,19,35) Treatment monitoring should also include assessment of possible adverse effects of therapy, interval fracture history, assessment of back pain, and body height measurement to determine whether VFA should be repeated. (36) There have been no analyses of the best frequency for reassessing fracture history, rescreening for vertebral fractures, or measuring height. Furthermore, the ideal interval for assessing BMD has not been studied and would depend on the difference between the patient's T-score and T-score goal and expected effects of the treatment.…”

“…More than a 2 cm (>3/4 inch) decrease in measured height indicates an increased probability that a new vertebral fracture has occurred and warrants spine imaging with repeat VFA or radiography. (36,37) For the same reasons, if height and spine imaging were not obtained at baseline, they should be considered early during treatment. These principles are based primarily on expert opinion and warrant additional analysis of the cost and benefits of this approach.…”

Canadian Consensus Conference on Osteoporosis, 2006 Update

“…[50][51][52][53][54][55] Measurement of height loss is a good clinical indicator of vertebral fracture. 56 Klotzbuecher et al 57 performed a meta-analysis of the risk of future fracture, given the history of prior fracture, and concluded that women with prior fracture had a 2-to 10-fold risk of another fracture, compared with those without fracture. This risk was reported to further increase with the number of prior vertebral fractures.…”

“…63 Postmenopausal women with historical height loss greater than 6 cm, prospective height loss greater than 2 cm, kyphosis, or acute incapacitating back pain syndrome should be sent for spine radiographs with specific request to rule out vertebral fractures. 56 …”

Height loss starting in middle age predicts increased mortality in the elderly

“…(7,11,12) Kyphosis and height loss are thought to result mainly from underlying vertebral fractures, but have not yet gained much clinical interest other than as markers for osteoporosis. (13)(14)(15)(16)(17)(18) Height loss, however, not only could be caused by vertebral fracture, but also to some extent by intervertebral disk degeneration that decreases disk height; osteoarthritic conditions of the spine, hip, or knee, various inflammatory and structural/congenital spinal deformities; and weakness of the back muscles. (19,20) Our previous report showed that height loss and vertebral deformity significantly and independently affected quality of life (QOL) in the elderly, and height loss aggravated QOL more significantly than did vertebral deformity in all domains, even with different effect patterns between height loss and vertebral deformity.…”