An Evaluation of Interlaminar Lumbar Instrumented (ILIF™)

Inclusion Criteria: * Patient is over 40 years of age; * Patient is diagnosed with single-level lumbar degenerative disc disease between L1-L2 and L4-L5 with evidence of disc collapse and symptomatic claudication with or without back pain and requires surgical intervention; * Patient is unresponsive to conservative treatment greater than or equal to six month 6 months, or exhibits progressive neurological symptoms in the face of conservative treatment; * Patient is willing and able to comply with the requirements defined in the protocol for the duration of the study; * Patient has signed and dated Informed Consent. Exclusion Criteria: * Patients with lumbar pathologies requiring surgical treatment at more than one level; * Patients with spondylolisthesis \> grade 1; * Patients with lytic spondylolisthesis or a defect of the pars interarticularis; * Patients with prior lumbar surgery at or adjacent to the operative level; * Patients with spinal metastases or active spinal tumor malignancy; * Progressive neuromuscular disease, e.g., muscular dystrophy, multiple sclerosis; * Present chronic steroid use; * Patients with rheumatoid arthritis or other autoimmune disease; * Patients who are pregnant or interested in becoming pregnant within the follow-up period of the study; * Patients with a history of substance abuse; * Patients involved in active spinal litigation; * Patients receiving workman's compensation for spinal conditions; * Patients who are mentally incompetent; * Patients who are incarcerated; * Patients who are unwilling or unable to comply with the follow-up protocol schedule of visits and assessments.