Fusion Rates of 3D Printed Porous Titanium Cages in Three and Four Level ACDFs

Inclusion Criteria: * ≥ 18 years old * Symptomatic multi-level degenerative cervical spondylosis necessitating anterior cervical arthrodesis in the subaxial cervical spine (between C2-T1). * Surgery performed within the Department of Neurological Surgery at The Ohio State University Wexner Medical Center (OSUWMC) * Cervical x-rays at 24 months (±60 days; retrospective comparison group only) Exclusion Criteria: * Traumatic spinal fractures or spinal cord injury * Previous cervical fusion surgery * Co-morbidity requiring medication use that may interfere with bone or soft tissue healing (i.e., high dose oral or parenteral glucocorticoids, immunosuppressive agents, methotrexate) - at discretion of investigator * Severe co-morbidities (e.g., heart, respiratory, or renal disease) * Recent (\<3 yrs) or co-incident spinal tumor or infection * Concurrent involvement in another investigational drug or device study that could confound study data (prospective exclusion only) * History of substance abuse (recreational drugs, prescription drugs or alcohol) that could interfere with protocol assessments and/or with the subject's ability to complete the protocol required follow-up * Subjects who are pregnant or plan to become pregnant in the next 24 months * Prisoner * Other contraindications for DePuy Conduit 3D printed titanium cage implant (prospective exclusion only)