Surgery for spinal stenosis involves making more space in the canal by removing the arthritis accumulation. This frequently involves an operation called a laminectomy, in which the roof over the canal and the underlying arthritis is removed. In some instances, a fusion, which entails growing adjacent vertebrae together with bone graft, is also performed. This is done when there is malalignment of the spine, excessive motion of the spine, or back pain originating from the area where the laminectomy is performed. Screws and rods may be used to help achieve a fusion. Surgery should be considered when standing, walking or lying flat and sleeping is so limited by spinal stenosis that it significantly interferes with a person's quality of life. The surgery stands an excellent chance of reducing the symptoms and improving a person's ability to stand, walk and sleep without pain or weakness. Rarely, bowel and bladder control can be affected by stenosis. In those cases, surgery is indicated to prevent further loss of function.