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pain. Hussein et al. 8 state that repair of three to four vertebrae per augmentation is reasonable. We also reported up to 16 repairs in one patient in the same paper (Figure 1e). While the majority (75%) of the 792 patients in this study required a single vertebral augmentation session, the median number of repairs was consistent with other studies at two per session. Augmentation repairs have been noted in levels up to the cervical area, and percutaneous repairs in the T3-L5 levels are considered safe and effective. 5,8 Others have differed in size requirements to successfully augment vertebral collapse and placed upper limits from T7 to T3. 10,11 However, repairs in our study were successfully made at the upper T1-T5 thoracic levels (4.7%). Subsequent to this study, we have successfully included some cervical levels. Limitations of our study include not assessing the potentially confounding effects of multiple myeloma therapy (for example, steroids) on outcomes, observational design, and participation and recall bias. Outcomes assessment was complicated by cancer therapy and/or relocation, and mortality, which was not assessed in this study, cannot be ruled out as a reason for nonresponse in some cases. This report comprises the largest study of distribution of compression fractures in consecutive multiple myeloma patients and prospectively acquired outcomes in patients undergoing vertebral augmentation to date.

A theoretical study of the F(2P) + OH(2Pi) --> HF(1Sigma+) + O(3P) reactive collisions is carried out on a new global potential energy surface (PES) of the ground 3A" adiabatic electronic state. The ab initio calculations are based on multireference configuration interaction calculations, using the aug-cc-pVTZ extended basis sets of Dunning et al. A functional representation of the PES shows no nominal barrier to reaction, contrary to previous results by others. Wave packet and quasiclassical trajectory calculations have been performed for this PES to study the F + OH(v = 0,j) reactive collision. The comparison was performed at fixed and constant values of the total angular momentum from 0 to 110 and relative translational energy up to 0.8 eV. The reaction presents a dynamical barrier, essentially due to the zero-point energy for the bending vibration near the saddle point. This determines two different reaction mechanisms. At energies higher than approximately 0.125 eV the reaction is direct, while below that value it is indirect and mediated by heavy-light-heavy resonances. Such resonances, also found in the simulations of the photodetachment spectrum of the triatomic anion, manifest themselves in the quasiclassical simulations, too, where they are associated to periodic orbits.