The present disclosure relates to bone cement formulations that have an extended working time for use in vertebroplasty procedures and other osteoplasty procedures together with cement injectors that include energy delivery systems for on-demand control of cement viscosity and flow parameters. The bone cement formulations may include a liquid component having at least one monomer and a non-liquid component including polymer particles and benzoyl peroxide (BPO). The non-liquid component may be further configured to allow controlled exposure of the BPO to the liquid monomer so as to enable control of the viscosity of the bone cement composition.
