A novel strategy of non-fusion instrumentation with coflex interlaminar stabilization after decompression for lumbar spinal stenosis

Lumbar spinal stenosis (LSS) is a pathological condition in which degenerative changes in the lumbar spine lead to spinal canal narrowing and compression of the dural tube and spinal nerve roots. Most patients with LSS have accompanying lumbar spondylosis with or without spondylolisthesis based on the aging process, and some experience regional low back pain due to spinal instability. Surgical treatment is indicated for patients with LSS who do not respond to conservative therapy. Conventional treatments are decompression alone and decompression plus spinal fusion using a pedicle screw and rod system with bone graft materials or a combination of anterior and posterior fusion. In terms of decompressive procedure, insufficient decompression can cause recurrence of stenosis after surgery; however, too much removal of the posterior elements and excessive facetectomy can cause postoperative spinal instability of the operated level. Iatrogenic fracture of the pars interarticularis due to massive laminectomy during surgery may result in isthmic spondylolisthesis. To avoid postoperative instability or to reduce regional low back pain due to degenerative spinal instability, additional spinal fusion is a promising strategy. Between 2002 and 2007 in the United States, 4,699 (79.4%) of 5,915 patients with stenosis plus spondylolisthesis were treated with decompression plus spinal fusion, whereas 19,699 (78.6%) of 25,060 patients with stenosis alone were treated with decompression alone (1). Whether additional spinal fusion is essential for LSS with low-grade spondylolisthesis remains controversial, but there is no doubt that spinal fusion is the gold standard operation for LSS.