The U-shaped device maintains height between the bones in the spine so nerves can exit freely and extend to lower extremities. Surgery for cervical myelopathy is either conducted from the front or from the back, depending on several factors such as where the compression occurs and how the cervical spine is aligned. Anterior cervical discectomy and fusion: A surgical treatment of nerve root or spinal cord compression by decompressing the spinal cord and nerve roots of the cervical spine with a discectomy in order to stabilize the corresponding vertebrae. Posterior approaches seek to generate space around the spinal cord by removing parts of the posterior elements of the spine. Techniques include laminectomy, laminectomy and fusion, and laminoplasty.Decompression plus fusion appears no better than decompression alone, while spinal spacers appears better than decompression plus fusion but not better than decompression alone. No differences were found in the type of decompression. Epidemiology
The NAMCS data shows the incidence in the U.S. population to be 3.9% of 29,964,894 visits for mechanical back problems. The Longitudinal Framingham Heart Study found 1% of men and 1.5% of women had vertebral slippage at a mean age of 54. Over the next 25 years, 11% of men and 25% of women developed degenerative vertebral slippage. Research
A RCT is being conducted in Sweden, to compare surgery versus non-surgical treatment for lumbar spinal stenosis. See also
Spinal cord compression

References
External links
"Spinal Stenosis". PubMed Health. National Center for Biotechnology Information, U.S. National Library of Medicine. 25 May 2010. Archived from the original on 8 February 2011.
Myelophthisic anemia (or myelophthisis) is a severe type of anemia found in some people with diseases that affect the bone marrow. Myelophthisis refers to the displacement of hemopoietic bone-marrow tissue by fibrosis, tumors, or granulomas. The word comes from the roots myelo-, which refers to bone marrow, and phthysis, shrinkage or atrophy. Causes
Myelophthisis can occur in the setting of chronic myeloproliferative disease (e.g. myelofibrosis), leukemia, lymphoma, and metastatic carcinoma or myeloma. It is common in people who have chronic idiopathic myelofibrosis. It has been linked to small-cell lung cancer, breast cancer or prostate cancer that metastasizes to the bone marrow.Currently, the most common cause is displacement of bone marrow by metastatic cancer (extramedullary hematopoiesis tends to be modest). Other causes include myeloproliferative disorders (especially late-stage or spent polycythemia vera), granulomatous diseases, and (lipid) storage diseases. Myelofibrosis can occur in all of these. Factors that may contribute to decreased RBC production include a decreased quantity of functioning hematopoietic tissue, disordered metabolism related to the underlying disorder, and, in some cases, erythrophagocytosis. Pathophysiology
Some cases of myelophthisis are thought to be related to the release of cytokines that simulate fibroblastic proliferation and fibrosis in the marrow. Diagnosis
The first test for diagnosis myelophthisis involves looking at a small sample of blood under a microscope. Myelophthisis is suggested by the presence of red blood cells that contain nuclei or are teardrop-shaped (dacryocytes), or immature granulocyte precursor cells which indicates leukoerythroblastosis is occurring because the displaced hematopoietic cells begin to undergo extramedullary hematopoiesis.