Lumbar canal stenosis (LCS) is a degenerative disease involving the lumbar vertebrae, discs, and ligamentum flavum that result in neurological deficit to some extent. The natural history of symptoms of LCS is highly important because they do not necessarily worsen with progressive degeneration. Therefore, a observation therapy is adopted for the treatment of this condition. Although invasive treatment is required for some patients, surgery cannot be performed solely on the basis of radiological findings and careful evaluation of neurological symptoms is necessary. In the event that spinal surgery is required, it is important to minimize degree of invasiveness; various devices and operative approaches and methods have been developed to this end. Our strategy for the surgical treatment of LCS involves microscopic decompression via a posterior approach. In our method, modified bilateral decompression via the splitting of the spinous process using an ultrasonic bone curette (SONOPET), and the results of this approach have been excellent. Our method is less invasive, facilitates the preservation of the paraspinal muscle, and represents a useful approach to posterior spinal elements. Our findings indicate that this method involves less muscle damage as compared to other methods. LCS should be differentiated from conditions other than those involving the spinal canal such as foraminal stenosis and far-out syndrome, piriformis syndrome, and tarsal tunnel syndrome. The incidence of these conditions is higher than appreciated and they present with neurological deficits similar to observed in LCS. Here, we report our criteria of operative indications for surger and the procedures that we developed for the treatment of LCS, based on a review of the available literature.