Lumbar Fusion With Nexxt Spine 3D-Printed Titanium Interbody Cages

Inclusion Criteria: * Subject is scheduled to undergo combined interbody and posterolateral spinal fusion surgery using either the Nexxt MatrixxTM 3D-printed titanium cage or HonourTM PEEK cage in conjunction with local autograft bone, and supplementation with a pedicle screw system. * Subject must be over the age of 18 years old. * Subject has been unresponsive to conservative care for a minimum of 6 months. * The subject must in the investigator's opinion, be psychosocially, mentally, and physically able to fully comply with this protocol including the required follow-up visits, the filling out of required forms, and have the ability to understand and give written informed consent. Exclusion Criteria: * Subjects with previous lumbar arthrodesis surgery. * Subjects requiring additional bone grafting materials other than local autograft bone. * Subject has inadequate tissue coverage over the operative site. * Subject has an open wound local to the operative area, or rapid joint disease, bone absorption, or osteoporosis. * Subject has a condition requiring medications that may interfere with bone or soft tissue healing (i.e., oral or parenteral glucocorticoids, immunosuppressives, methotrexate, etc.). * Subject has an active local or systemic infection. * Subject has a metal sensitivity/foreign body sensitivity. * Subject is morbidly obese, defined as a body mass index (BMI) greater than 40. * Subject has any medical condition or extenuating circumstance that, in the opinion of the investigator, would preclude participation in the study. * Subject is currently involved in another investigational drug or device study that could confound study data. * Subject has a history (present or past) of substance abuse (recreational drugs, prescription drugs or alcohol) that in the investigator's opinion may 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 12 months or who are lactating. * Subject is involved in or planning to engage in litigation or receiving Worker's Compensation related to neck or back pain. * Subject is a prisoner.