The purpose of this study is to evaluate the safety and effectiveness of XL TDR in patients with single-level degenerative disc disease compared to other devices approved by the FDA for the same or similar indications.

The XL TDR® eXtreme Lateral Total Disc Replacement consists of two endplates that are provided in a number of sizes to accommodate a variety of patient anatomies and pathologies. The XL TDR device is made up of a ball and socket articulation and the joint is made of CoCrMo alloy.

The XL TDR is intended to be used to reconstruct the spine following the removal of part or all of the intervertebral disc on one level of the lumbar spine.

The XL TDR is indicated for reconstruction of the disc following discectomy in skeletally mature subjects with symptomatic degenerative disc disease (DDD) of the lumbar spine at one level from L1-L5. DDD is defined as discogenic back pain with degeneration of the disc confirmed by patient history radiographic studies.

Inclusion Criteria:

• 18-70 years of age (inclusive and skeletally mature) at the time of surgery
• Diagnosis of image-confirmed symptomatic DDD at one of the following levels: L1/L2, L2/L3, L3/L4, or L4/L5
• DDD diagnosed using patient history and image-confirmation such as (but not limited to), MRI, CT, or CT Myelogram with one or more of the following factors: contained herniated nucleus pulposus, facet joint degeneration/changes, decreased disc height >2mm, and/or scarring/thickening of ligamentum flavum, annulus fibrosis, or facet joint capsule
• Preoperative ODI ≥ 30 points
• Unresponsive to conservative treatment for ≥ 6 months

Exclusion Criteria:

• Symptomatic multilevel lumbar degeneration
• Chronic back or leg pain of unknown etiology
• Non-contained or extruded herniated nucleus pulpous
• Previous or other lumbar surgery at any level except prior discectomy, laminotomy, or nucleolysis at the same level
• Involved vertebral endplates dimensionally smaller than 45mm in the medial-lateral and/or 20mm in the anterior/posterior directions
• Idiopathic scoliosis
• Defect in the pars interarticularis
• Radiographic signs of significant instability at operative level
• Lytic spondylolisthesis or degenerative spondylolisthesis > than grade 1
• Bony lumbar spinal stenosis
• Radiographic confirmation of significant facet joint disease or degeneration
• Another lumbar device implanted
• Clinically compromised vertebral bodies at the affected level due to trauma
• Presence of metastases or active spinal tumor malignancy
• Osteopenia, osteoporosis, or metabolic bone disease
• Active local or systemic infection, including AIDS and hepatitis
• Rheumatoid arthritis or other autoimmune disease
• Taking any medications or supplements which potentially interfere with bone/soft tissue healing
• Progressive neuromuscular disease
• Allergy to device materials, specifically: cobalt-chromium-molybdenum alloy, titanium, and hydroxyapatite
• BMI >40
• Pregnant, or may become pregnant within follow-up period of study
• Enrolled in another investigational study within the last 90 days
• Waddell signs of inorganic behavior ≥3
• History of substance abuse
• Involved in active spinal litigation
• Receiving workman's compensation for spinal condition
• Mentally incompetent
• Incarcerated
• Unwilling or unable to comply with all protocol visits/assessments