Table 1

Study entrance eligibility criteria.

Criteria
Inclusion Criteria

  1. Minimum age of 21 y but not greater than 80 y

  1. Skeletally mature

  1. Have a confirmed diagnosis of lumbar DDD requiring single-level fusion between L2 and S1. Lumbar DDD diagnosis confirmation shall be determined by subject history, physical examination, and radiographic studies with one or more of the following factors:

    • ­ Instability as defined by >3 mm translation or ≥5° angulation

    • ­ Osteophyte formation of facet joints or vertebral endplates

    • ­ Decreased disc height, on average by >2 mm, but dependent upon the spinal level

    • ­ Scarring/thickening of the ligamentum flavum, annulus fibrosis, or facet joint capsule

    • ­ Herniated nucleus pulposus

    • ­ Facet joint degeneration/changes

    • ­ Vacuum phenomenon

  1. Report preoperative low back pain score of ≥40 mm on a 100-mm VAS correlating with involved level

  1. Report preoperative ODI score of ≥40

  1. Received at least 6 months of conservative (nonsurgical) treatment without sufficient relief from symptoms

  1. Willing and able to comply with follow-up evaluations per protocol, including completion of self-assessment survey questionnaire(s), and has read, understood and signed the sponsor and Institutional Review Board–approved site-specific informed consent form

Exclusion Criteria

  1. Previous implant surgery (ie, fusion procedure or total disc replacement) at the index level (Note: Previous less invasive procedures such as laminectomy, discectomy, etc, at the index level are not considered exclusionary)

  1. Greater than grade I spondylolisthesis

  1. Presents with a diagnosis of symptomatic nonindex level lumbar DDD between L2 and S1. Nonindex level lumbar DDD diagnosis confirmation shall be determined by subject history, physical examination, and radiographic studies with one or more of the following factors:

    • ­ Instability as defined by >3 mm translation or ≥5° angulation

    • ­ Osteophyte formation of facet joints or vertebral endplates

    • ­ Decreased disc height, on average by >2 mm, but dependent upon the spinal level

    • ­ Scarring/thickening of the ligamentum flavum, annulus fibrosis, or facet joint capsule

    • ­ Herniated nucleus pulposus

    • ­ Facet joint degeneration/changes

    • ­ Vacuum phenomenon

  1. Active systemic infection or infection local to the surgical site

  1. Active or suspected malignancy

  1. BMI of ≥40

  1. Significant metabolic bone disease (eg, osteoporosis or osteomalacia) to a degree that would contraindicate spinal instrumentation. Osteoporosis is defined as a T-score of < -2.5 on a DEXA scan A screening questionnaire for osteoporosis, SCORE, will be administered to identify those patients that require a DEXA scan (SCORE ≥6 requires DEXA scan)

  1. Taking medications that are known to potentially interfere with bone or soft tissues healing (eg, chronic systemic steroids)

  1. Has a current diagnosis of substance-related disorder, as defined per DSM-V, May 2013

  1. Has a diagnosis of somatoform, dissociative, eating, or psychotic disorder per DSM–V

  1. Waddell signs of inorganic behavior (3 or more signs)

  1. Is a current tobacco user (current use defined as tobacco use ≤30 d prior to surgery

  1. Is a prisoner at the time of enrollment

  1. If female: pregnant/contemplating pregnancy during the follow-up period

  1. Enrolled in a concurrent clinical investigation that may confound the findings of the present investigation

  • BMI, body mass index; DDD, degenerative disc disease; DEXA, dual-energy x-ray absorptiometry; DSM-V, Diagnostic and Statistical Manual of Mental Disorders 5th Edition; ODI, Oswestry Disability Index; SCORE, simple calculated osteoporosis risk estimate; VAS, visual analog scale.