<qa>  What is the primary endpoint of the study?This is a prospective, multi-center randomized, controlled study designed to evaluate the safety and effectiveness of Cortoss Synthetic Cortical Bone Void Filler in vertebral augmentation using the percutaneous vertebroplasty technique. Study eligible patients with painful osteoporotic compression fractures will be randomized 2:1 to vertebroplasty with Cortoss treatment group or PMMA control group, respectively. Patients will not be told which treatment they will receive single blind study design. Safety and effectiveness will be determined by comparing the success rate of the treatment group to the success rate of the control group. Secondary endpoints will include Quality of Life, Patient satisfaction, evaluation of the patients pain and function post-operatively compared to baseline, and maintenance of vertebral body height and alignment. 