The purpose of this randomized controlled trial is to assess and compare radiographic and clinical outcomes in patients who are to undergo combined interbody/posterolateral lumbar fusion procedures, supplemented with pedicle screw instrumentation, using one of the following interbody cages; the Medtronic Adaptix™ cage with roughened micro and nano-textured titanium surfaces or the CAPSTONE® poly-ether-ether-ketone cage.

The randomized controlled trial will prospectively evaluate the efficacy of Medtronic Adaptix™ titanium implants supplemented with a pedicle screw system as compared to a Medtronic CAPSTONE® PEEK cage currently used in routine fashion for lumbar interbody fusion procedures. This study will capture clinical and radiographic outcomes on patients up to 2 years postoperatively. Both cages will be used in conjunction with a 50:50 mixture of autograft: allograft using milled local autograft bone and GRAFTON™ DBM DBF (no iliac crest autograft will be utilized).

This single-centered study will enroll up to 100 subjects, with subjects followed for 24 months post-surgery. All subjects enrolled in the study will be recruited from a pool of subjects eligible for combined interbody/posterolateral lumbar fusion surgery. The inclusion/exclusion criteria are listed below.

Inclusion Criteria:

1. Subject is scheduled to undergo combined interbody and posterolateral spinal fusion surgery using either the Medtronic Adaptix™ titanium cage or Medtronic CAPSTONE® PEEK cage in conjunction with a 50:50 mixture of local autograft and GRAFTON™ DBM DBF, and supplementation with a pedicle screw system.
2. Subject must be over the age of 18 years old.
3. Subject has been unresponsive to conservative care for a minimum of 6 months.
4. 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:

1. Subjects with previous lumbar arthrodesis surgery.
2. Subjects requiring additional bone grafting materials other than local autograft bone or GRAFTON™ DBM DBF.
3. Subject has inadequate tissue coverage over the operative site.
4. Subject has an open wound local to the operative area, or rapid joint disease, bone absorption, or osteoporosis.
5. Subject has a condition requiring medications that may interfere with bone or soft tissue healing (i.e., oral or parenteral glucocorticoids, immunosuppressives, methotrexate, etc.).
6. Subject has an active local or systemic infection.
7. Subject has a metal sensitivity/foreign body sensitivity.
8. Subject is allergic to antibiotics (gentamicin) or processing solutions found in GRAFTON™.
9. Subject is morbidly obese, defined as a body mass index (BMI) greater than 45.
10. Subject has any medical condition or extenuating circumstance that, in the opinion of the investigator, would preclude participation in the study.
11. Subject is currently involved in another investigational drug or device study that could confound study data.
12. 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.
13. Subjects who are pregnant or plan to become pregnant in the next 12 months or who are lactating.
14. Subject is involved in or planning to engage in litigation or receiving Worker's Compensation related to neck or back pain.
15. Subject is a prisoner.

Subjects will be blinded to their group status for the duration of the study assessments and procedures (24 months post-operatively).