Pedicle Osteotomy for Stenosis Trial

LSS is a narrowing of the spinal canal and/or the intervertebral foramina by bony spurs or soft tissues that decrease space for the neural elements resulting in compression of the nerve roots or spinal cord in the lumbar region of the spine. LSS can cause low back pain, weakness, numbness, and pain and loss of sensation in the buttocks and legs. In most cases the symptoms improve when the patient is sitting or leaning forward, due to the flexed position of the vertebra which leads to reduced impingement of the neural tissue. In addition, many patients with LSS complain of pain when standing and walking referred to as neurogenic intermittent claudication (NIC). Nonsurgical management is well-established as the first-line treatment approach for LSS patients with mild to moderate symptoms. It typically involves the prescription of modified physical activity, physiotherapy, anti-inflammatory drugs, epidural steroid injections, use of a lumbar corset or some combination thereof. Surgical treatment is reserved for patients who do not obtain adequate relief of symptoms by conservative management. The goal of surgical treatment for LSS is to relieve the compression of the spinal nerves in the spinal canal or neural foramina. Such decompressive surgery generally involves laminectomy, laminotomy, foraminotomy, partial facetectomy or some combination thereof. Decompressive surgery in subjects with LSS and spondylolisthesis commonly requires fusion to stabilize the spondylolisthesis. The most commonly performed lumbar fusion for patient's with the combination of LSS and spondylolisthesis is a Transforaminal Lumbar Interbody Fusion (TLIF) which involves stabilizing the motion segment by placing pedicle screws, rods and an interbody fusion cage. Autograft or allograft bone are commonly used to bring about fusion or a bridging of bone across the intervertebral joint. The Altum® Pedicle Osteotomy System contains the implants and instruments required to perform the pedicle lengthening osteotomy procedure for the treatment of LSS. The Altum® implant is an expandable bone screw that is available in a variety of sizes (7.5 mm, 8.5 mm and 9.5 mm). Altum® instruments are manufactured from IXEF PARA GS-1022 GY/51, medical grade titanium alloy (Ti 6AL-4V ELI ASTM F-136), and medical grade stainless steel (17-4 ASTM F899).