Lumbar stenosis is a well-described pathologic condition typically resulting from spondylosis. This occurs throughout the spine but is more prevalent in the cervical and lumbar regions where relatively mobile segments combined with axial loading can lead to degenerative arthritic changes. A combination of hypertrophied facet joints and ligaments, disc herniation, spondylolisthesis, www.selleckchem.com/products/Imatinib(STI571).html and osteophyte overgrowth can lead to lumbar stenosis and subsequent compressive neurologic symptoms [1]. This chronic and debilitating condition affects 5 out of 1000 Americans older than 50 years. Surgical decompression of lumbar stenosis is the most common surgery for patients older than 65 years of age [2]. Prospective randomized clinical trials have shown significantly greater improvements in patient functional outcome and quality of life with surgical intervention compared to medical management [2, 3].

The Maine Lumbar Stenosis Study and the Spine Patient Outcomes Research Trial (SPORT) have both shown statistically significant improvement in patient outcomes. Although some studies have reported that the beneficial effects downtrend over time, the SPORT trial suggested continued improvement of the beneficial effect [4�C6]. Traditionally, lumbar stenosis is treated with an open, decompressive laminectomy with or without facetectomies. This has been very effective for improvement of clinical symptoms but may inadvertently lead to cases of iatrogenic spinal instability, requiring additional surgical intervention for stabilization [7�C14].

Radiographic studies, cadaver models, and finite element analyses have shown that open decompressive laminectomies are effective for lumbar stenosis but may also disrupt the native anatomic support structures (supraspinous ligament, interspinous ligament, spinous process, lamina, facet joints, ligamentum flavum, and paraspinal musculature) leading to muscular atrophy [15�C21] and potential long-term spinal instability [22, 23]. Subsequently, ��minimally invasive spine surgery�� (MISS) was developed to focally address the diseased structures but minimize disruption of the surrounding normal anatomic structures (Figure 1). Muscle splitting serial tube dilators and retractors were designed to minimize disruption of the paraspinal musculature and provide direct and focal access to the diseased anatomy [24, 25].

Figure 1 Dacomitinib Illustrations of intraoperative surgical exposure and postoperative cross-sectional CT of lumbar spine with spinal canal decompression. Open laminectomy (a) and (b). Minimally invasive microendoscopic decompression (c) and (d). Recent studies by multiple authors have shown similar patient outcomes with MISS approaches for lumbar decompression when these techniques are compared to the traditional open approach.