The purpose of this clinical investigation was to collect clinical evidence of the safety and efficacy of the OsseoScrew System. The OsseoScrew System is intended to provide immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion. The study was designed to compare the safety and efficacy of OsseoScrew compared to any other commercially available fenestrated pedicle screw system augmented with PMMA for posterior spinal fixation after surgical correction of spinal deformity or pathology.

This was a randomized, open-label, controlled, multi-center study in which patients were randomized in a 1:1 ratio to receive either the OsseoScrew or any commercially available fenestrated screw augmented with polymethylmethacrylate (PMMA) (Control group) for posterior spinal fixation after surgical correction of spinal deformity or pathology. The study was planned to include up to 150 skeletally mature patients with spinal instability and osteopenia at up to 10 sites. Patients were to return postoperatively at 6 weeks (± 2 weeks) and at 6, 12, and 24 months (± 2 months) for assessments.

Inclusion Criteria:

1. ≥ 18 years of age
2. Spinal instability or deformity requiring fusion with instrumentation
3. Osteopenia defined as (T-Score of less than -1.0)
4. No response to nonoperative treatment modalities preceding enrollment.
5. Subject is willing and able to provide informed consent and agrees to release medical information for purposes of this study and to return for scheduled follow-up evaluations

Exclusion Criteria:

1. Active systemic or local infection
2. A life expectancy less than the study duration
3. Autoimmune disorders
4. Currently an alcohol, solvent, or drug abuser
5. Psychiatric or cognitive impairment that, in the opinion of the investigator, would interfere with the subject's ability to comply with the study requirements
6. History of allergies to any of the device components including but not limited to commercially pure titanium, titanium alloy, polymethylmethacrylate or Zirconium Oxide (ZrO2)

150 skeletally mature study subjects with spinal instability and osteopenia will be enrolled in the study. Subjects will be randomized 1:1 to the OsseoScrew or the control group.