The effects of alendronate on stature and the spine deformity index

Several diagnostic tools are now available to assess the presence and severity of vertebral deformity in patients with osteoporosis. In addition to categorical x-ray confirmation of fracture, a spine deformity index (SDI) has been developed to quantify vertebral deformity. Sequential measurements of stature are also valuable, and both methodologies have been used in Phase III clinical trials to assess the efficacy of alendronate to treat postmenopausal osteoporosis. In these clinical trials, the SDI increased (worsened) in 41% of placebo-treated patients and 33% of alendronate-treated patients (P = 0.028). Alendronate reduced mean stature loss by 35% (P = 0.005). These beneficial effects were consistent in older and younger women, and in those with and without baseline vertebral fractures. Spine deformity index and stature results corresponded with a 48% reduction in categorical vertebral fractures (assessed by means of digitized x-ray analysis) in these trials. Taken together, these data show that treatment with alendronate progressively reduced the risk for vertebral deformity height loss and vertebral fracture over 3 years of therapy.