• Early and sustained decrease in pain (efficacy prong of primary endpoint) at 24 months compared to baseline using the Visual Analog Scale (VAS)
  
• Maintenance or improvement in function (efficacy prong of primary endpoint) at 24 months compared to baseline using the Oswestry Disability Index (ODI)
  

• Maintenance or improvement in quality of life (secondary endpoint) at 24 months compared to baseline using the SF-12
  
• Maintenance of treated vertebral height and alignment (secondary endpoint) at 24 months compared to baseline using diagnostic radiography
  

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 patient's pain and function post-operatively compared to baseline, and maintenance of vertebral body height and alignment.

For the purposes of this study, vertebral augmentation, or vertebroplasty, is defined as a minimally invasive procedure utilizing manual instruments and radiological guidance to deliver an in-situ polymerizable material to stabilize a collapsed or fractured vertebral body. The goal is to alleviate pain caused by the fracture and enhance or prevent further deterioration of function.

This multi-center study will evaluate Cortoss for the augmentation of one or two vertebra(e), fractured as a result of osteoporosis, located between (and including) the levels of the sixth thoracic and the fifth lumbar vertebrae. A total of 243 patients will be enrolled at up to 19 sites. All subjects must have radiographic evidence of a vertebral body fracture due to osteoporosis. After complying with all eligibility criteria, subjects will sign an informed consent document and will be randomized into vertebroplasty treatment with Cortoss or PMMA (1:1 ratio). Patients will be followed for at least 24 months and recruitment is expected to take between 9 and 12 months. Visits and assessments are planned according to the time and events schedule.

Inclusion Criteria:

• Are at least 18 years of age
• Have sustained a painful osteoporotic vertebral compression fracture (VCF) for at least 4 weeks but no longer than 1 year or have radiographic evidence of at least 5% worsening vertebral collapse as compared to previous radiographic evidence
• Give written Informed Consent to participate in the study and be willing to comply with protocol requirements
• Have pain requiring the regular use of analgesics or have a substantially altered life-style due to pain or disability
• Have central pain over the spinous process upon palpation at the planned level(s)
• Are appropriately communicative to verbalize and differentiate with regard to location and intensity of their pain
• Are physically and mentally willing and able to comply with the clinical and radiographic follow-up schedule
• Have radiographic evidence of one or two, Grade 1 or greater according to Genant's criteria, osteoporotic VCF(s) between (and including) the level of the sixth (6th) thoracic to the fifth (5th) lumbar
• Have an acute or persistent (not healed) fracture demonstrated by magnetic resonance imaging (MRI) or bone scan
• Have a patient self-assessment VAS score >= 50 mm at the pre-treatment visit
• Have a 30% or greater disability score on the baseline ODI (version 2.0).

Exclusion Criteria:

• Have significant vertebral collapse defined as more than 70% of original vertebral height, or a burst or pedicle fracture with posterior cortical wall disruption
• Have posterior vertebral wall displacement occupying more than 20% of the cross sectional area of the spinal canal
• Have neurologic symptoms or deficits, or radiculopathy related to the VCF
• Have pain based on a clinical diagnosis of herniated nucleus pulposus, high energy trauma, severe spinal stenosis as evidenced by progressive weakness or paralysis, or bone tumor at the level(s) of pathology as evidenced by computed tomography (CT) scan
• Have indications of instability related to the VCF at the level to be treated (e.g., neurologic deficit, kyphosis > 30º, translation > 4 mm, and/or interspinous process widening)
• Have canal compromise causing clinical manifestations of cord, neural foramen, or nerve root compression at the level(s) to be treated
• Have a bleeding disorder, including coagulopathy
• Have severe cardiopulmonary deficiencies
• Have an active systemic or local infection
• Are currently being treated for cancer or HIV
• Have a known allergy to acrylics (e.g., methyl methacrylate)
• Subject is currently an alcohol, solvent or drug abuser
• Female patients who are pregnant or nursing, or of childbearing potential not using a reliable contraceptive method
• Are involved in medical litigation
• Are prisoners
• Have participated in another investigational study within 30 days prior to inclusion