Strontium ranelate is a new therapeutic approach to osteoporosis. Strontium ranelate’s mode of action involving dissociation of bone formation and resorption was shown in preclinical studies, explaining its efficacy on bone. In a recent study [1], 2D and 3D bone microarchitecture was determined from bone biopsies in postmenopausal women treated with strontium ranelate. One hundred forty-one transiliac bone biopsies were obtained from 133 postmenopausal osteoporotic women: 49 biopsies after 1–5 yr of 2 g/d strontium ranelate and 92 biopsies at baseline or after 1–5 yr of placebo.

3D analysis of biopsies after 3-yr of treatment (20 biopsies) and placebo (21 biopsies) using ¿CT showed significant changes in microarchitecture with, in the strontium ranelate group, higher cortical thickness and trabecular number, and lower structure model index and trabecular separation, with no change in cortical porosity.

The changes in 3D microarchitecture enhance bone biomechanical competence and explain the decreased fracture rate at vertebral, nonvertebral and hip levels with strontium ranelate.

1. Arlot ME et al. J Bone Miner Res. 2008;23:215-222