Comparison of the Aspen Device Versus Pedicle Screws for Supplemental Posterior Fixation in Lumbar Interbody Fusion

Inclusion Criteria:

• Age between 18 and 75 years
• Scheduled for an elective single-level circumferential lumbar fusion by means of supplemental posterior fusion with fixation (allowing for the placement of ASPEN or pedicle screws) for an anterior or lateral interbody fusion
• Diagnosis of primary symptomatic Degenerative Disc Disease (DDD) and/or spondylolisthesis confirmed with appropriate imaging studies and/or positive lumbar discography
• Oswestry Disability Index (ODI) v2.1 score > 30%
• Failed at least 3 months of conservative care (non-surgical) OR has clinical signs of neurological deterioration
• Signed Informed Consent Form

Exclusion Criteria:

• Previous fusion at the operative level
• Spondylolisthesis Grade 3 or more
• Lytic spondylolisthesis
• Incompetent or missing posterior arch at the affected level (e.g. complete laminectomy, pars defect)
• Requires complete laminectomy at level of surgery
• Facet joints at implant level are absent or fractured
• Vertebral body compromise or acute fracture at implant level
• Body mass Index (BMI) ≥ 35
• Known allergy to titanium
• Osteoporosis: Simple Calculated Osteoporosis Risk Estimation (S.C.O.R.E.) > 6 AND Dual-energy X-ray absorptiometry (DEXA) T-score < -2.5
• Paget's disease, osteomalacia, or any other metabolic bone disease
• Use of medications or any drug known to potentially interfere with bone/soft tissue healing (e.g. chronic systemic steroids)
• Planned use of additional segmental fixation (eg. facet screws)
• Planned use of Bone Morphogenetic Protein (BMP) for posterolateral fusion*
• Unlikely to comply with the follow-up evaluation schedule
• In the opinion of the Investigator, Subject has history of chemical substance dependency or significant psychosocial disturbance that may impact the outcome or study participation
• Active participation in a clinical trial of another drug or device
• Active systemic infection or any other health condition that would preclude surgery
• History of invasive malignancy, except if the subject has received treatment and displayed no clinical signs and symptoms for at least five years
• Subject is a prisoner
• Pregnant or planning to become pregnant during the length of study participation
• Involvement in active litigation related to back problems at the time of screening
• Direct involvement in the execution of this protocol
• Pre-existing conditions that could interfere with the evaluation of outcome measures (e.g. musculoskeletal, neuromuscular, etc.)