STUDY DESIGN:This study is a prospective, multi-center, randomized controlled "Conditions of Use" clinical trial comparing the Superion® IDS to open, direct decompression in the treatment of subjects aged 45 or older suffering from moderate symptoms of neurogenic intermittent claudication secondary to a confirmed diagnosis of moderate LSS at one or two contiguous levels from L1 to L5, i.e. from the L1-L2 level to the L4-L5 level. A maximum of 20 investigative sites in the U.S. will enroll subjects into the trial using a 1:1 randomization assignment. Enrollment will include 358 subjects (152 per arm, plus 18% to account for lost to follow-up). An investigative site is defined as a facility or facilities in the same general geographic location if they are under the control of a local Institutional Review Board (IRB).
After implantation of the Superion® IDS or performance of the direct decompression, each Investigator will be permitted to provide a postoperative care regimen based on the subject's specific need. The regimen may include, but need not be limited to: medications, a corset or brace, acupuncture, traction, physical therapy, chiropractic treatment, use of a TENS unit and massage therapy. The type and amount of the postoperative care will be collected.
At each follow-up visit through 60 months, subjects will be interviewed to determine if they have experienced adverse events (AEs) since the previous follow-up visit. A neurological assessment will be performed for all patients at baseline and all follow-up visits. All subjects will be required to complete ZCQ, ODI, VAS, EQ-5D and the VertiFlex® Patient Satisfaction questionnaires to evaluate disability, function, pain, quality of life and satisfaction at each follow-up visit. Subjects are also required to complete a VAS questionnaire to evaluate pain status at discharge.
The potential impact of spinal injections/nerve blocks use on the ZCQ was evaluated based on review of the medical literature. As these are potentially confounding of the ZCQ outcomes, epidural steroid injections or nerve block procedures at the treated level(s) will be deemed failures. Further, rhizotomy procedures at the treated level(s) will be deemed failures.
With respect to spinal cord stimulators, because the use of a permanent implant would require a surgical procedure, this will be deemed a device failure.
Radiographic evaluations will be performed at discharge, and at each scheduled follow-up visit and prior to any re-operations, in accordance with the Radiographic Evaluation Protocol. The Investigator may also obtain x-rays at unscheduled visits or to assess adverse events, if clinically indicated.
