A Randomized Controlled Trial Comparing Surgical Decompression With an Interlaminar Implant in Patients With Intermittent Neurogenic Claudication Caused by Lumbar Stenosis

Inclusion Criteria: * signed informed consent * is 40 to 85 years old at time of surgery * has INC, as noted by leg/buttock/groin pain with or without back pain. Leg/buttock/groin pain needs to be strongly relieved when flexed such as when sitting in a chair * has received at least three months of conservative care therapy which may have included, but is not limited to, physical therapy, bracing, systemic and/or injected medications * has a regular indication for surgical intervention of INC * has a narrowed lumbar spinal canal, nerve root canal or intervertebral foramen at one or two levels confirmed by MRI * is physically and mentally willing and able to comply with, or has a caregiver who is willing and able to comply with, the post-operative evaluations. Exclusion Criteria: * has cauda equina syndrome defined as neural compression causing neurogenic bowel (rectal incontinence) or bladder dysfunction (bladder retention or incontinence) * has Paget's disease, severe osteoporosis or metastasis to the vertebrae * has significant scoliosis (Cobb angle \> 25 degrees) * has a Body Mass Index (BMI) \> 40 kg/m2 * has had any surgery of the lumbar spine * has degenerative spondylolisthesis \> grade 1 (on a scale 1 to 4) at the affected level * has significant instability of the lumbar spine * has severe comorbid conditions that will increase the risk to the patient or interfere with the evaluability of this study * has a fused segment at the indicated level. * has a herniated disk on the level of interest