InterFuse® S and T for the Treatment of Scoliosis, Spondylolisthesis and Degenerative Disc Disease (DDD)

Inclusion Criteria: * 1\. The patients has a planned fusion construct of at least five levels and will have the InterFuse (S) or (T) planned for L5-S1 and/or L4-L5. 2\. The patient has documented conservative (non-operative) treatment for at least 6 months. 3\. The patient has a VAS score of ≥ 60 mm for Back and/or Leg. 4. The patient has an ODI ≥ 40%. 5. The general condition of the patient is appropriate for surgery, as evaluated by the Investigator. 6\. The patient is willing and able to comply with study requirements. 7. The patient has agreed to participate in the study Exclusion Criteria: * 1\. The patient has undergone any prior spinal fusion surgery at the proposed treatment level(s). Previous non-fusion surgery at the proposed treatment level(s) is acceptable. 2\. The patient has osteoporosis or severe osteopenia as determined by the Investigator. A clinical SCORE calculator may be utilized for females over 40 years of age. 3\. The patient has grade 2 or higher spondylolisthesis or retrolisthesis at the affected level(s). 4\. The patient has known neoplastic disease other than skin cancer. 5. The patient has a Body Mass Index (BMI) of greater than 40; BMI = wt (kg)/ht2 (m2). 6\. The patient has an active infection. 7. The patient is pregnant or is planning on becoming pregnant in the next two years. 8\. The patient is mentally ill or has a history of drug abuse or severe depression/ psychosocial issues. 9\. The patient has a known allergy to polyether ether ketone (PEEK), stainless steel or tantalum. 10\. The patient is currently enrolled in an investigational spine study. 11. The patient has rheumatoid arthritis, ankylosing spondylitis or other autoimmune disease. 12\. The patient has symptomatic fibrous arachroiditis.