Table 1. Inclusion and exclusion criteria.

Inclusion criteria

≥18 years of age

Patients presenting with lumbar spondylolisthesis, stenosis, degenerative disc disease including herniation, spinal instability, spondylosis, radiculopathy and/or myelopathy as diagnosed by their respective spine surgeon based on patient history, physical examination, and radiographic assessment

Patients receiving Valeo I or II Si3N4 interbody fusion devices

No improvement in symptoms within ≥6 weeks of conservative therapy

All studies with a surgical date at least 6 months prior to initiation of the data collection process

Exclusion criteria

None