Back Pain and Sciatica

Description

Alternative Names

Surgery

Discectomy is the surgical removal of the diseased disc, which then relieves pressure on the spine. The procedure has been performed for 40 years with increasingly less invasive technique being developed over time. Oddly, few studies have been conducted to determine its real effectiveness. Although in appropriate candidates it provides faster immediate relief than medical treatment, long-term superiority (over five years) is uncertain. A number of minimally invasive variations are now available.

When the soft, gelatinous central portion of an intervertebral disk is forced through a weakened part of a disk, it is a condition known as a slipped disk. Most herniation takes place in the lumbar area of the spine, and it is one of the most common causes of lower back pain. The mainstay of treatment for herniated disks is an initial period of rest with pain and anti-inflammatory medications followed by physical therapy. If pain and symptoms persist, surgery to remove the herniated portion of the intervertebral disk is recommended.

Microdiscectomy. Microdiscectomy is the current standard procedure. It is performed through a small incision (1 to 1 1/2 inch). The back muscles are lifted and moved away from the spine. After identifying and moving the nerve root, the surgeon removes the injured disc tissue under it. The procedure does not change any of the structural supports of the spine, including joints, ligaments, and muscles.

Other less invasive procedures that are available including the following:

• Endoscopic Discectomy. Endoscopy employs a catheter (a thin tube) that contains tiny cameras and surgical instruments that are inserted through small incisions. Various endoscopic approaches are proving to be useful for back surgery.
• Percutaneous Discectomy. Percutaneous discectomy (PAD). This approach uses a tube with a device at the tip that cuts away some of the nucleus pulposus and a vacuum that then sucks this gelatinous matter out.
• Laser Discectomy. A number of investigative surgical procedures employ lasers. For examples, endoscopic laser foraminoplasty (ELF) uses lasers to locate the likely source of pain and remove diseased tissue. The incision requires little more than a Band-Aid and complications are minimal. Long term benefits are unknown, however.

It is not clear yet if any of the these less invasive procedures are any more effective than the standard microdiscectomy.

Complications and Outlook. Many patients still have back pain after discectomy that delays discharge from the hospital. Narcotics are usually needed. Adding an injected NSAID may speed resolution of pain.

Scar tissue is a significant problem, since it can cause persistent low back pain afterward. Anti-scarring agents or certain devices may help reduce surgical scars and thereby postoperative pain. Other complications of spinal surgery can include nerve and muscle damage, infection, and the need for reoperation.

Patients now often remain in bed only three or four days after disc surgery. It may take four to six weeks for full recovery, however. Gentle exercise may be recommended at first. Starting intensive exercise four to six weeks after a first-time disc surgery appears to be very helpful for speeding up recovery.

Laminectomy

Operations that remove a vertebra (laminectomy) or shave off part of one (laminotomy) may be used in certain cases of spinal stenosis or spondylolisthesis to decompress the nerve. They may also be used to remove benign tumors on the spine. In a 2002 study laminectomy achieved a 68% improvement compared to 33% in patients not given surgery.

Click the icon to see an illustrated series detailing lumbar spinal surgery.

Although either procedure often brings immediate relief from pain, a 1999 statistical study suggested that it is inappropriately performed in 60% or more of sciatica cases. There are small risks to the operation and it is not always successful. Some recurrence of back pain and sciatica occurs in half to two-thirds of postoperative patients. Minimally invasive variations are under investigation.

Spinal Fusion

In some case in which abnormal vertebrae position or movement is responsible for severe and chronic back pain, such as spinal stenosis or spondylolisthesis, surgeons may fuse vertebrae together. Fusion employs a bone graft or some other device to join the vertebrae together. In a 2001 study of patients with severe long-term back pain, 33% of patients who had spinal fusion had less back pain after two years, compared to 7% who received conservative treatment with physical therapy. Pain improved most in the six months following surgery. The patients who had surgery also had less disability and depression.

Many spinal fusion surgeries use a tiny hollow metal cage, which is implanted into the disc space. Bone is then removed from the patients hip and packed inside the cage. Over time the bone grows through the holes and around the device, fusing the vertebrae. Alternatively, rather than performing a bone graft, the cage is filled with a sponge-like material containing a genetically-engineered protein called InFuse (rhBMP-2) that promotes bone to grow.

Click the icon to see an illustrated series detailing spinal fusion.

A number of video-assisted techniques have been developed that are less invasive than standard "open" surgical approaches, which uses wide incisions. To date, however, the newer procedures have higher complication rates than the open approaches and some medical centers have abandoned them.

Other Techniques

Intradiscal Electrothermal Treatment (IDET). Intradiscal electrothermal treatment (IDET) is a promising outpatient procedure for very select patients. It employs a hollow needle that is inserted into the painful disk. An electric wire passed through the need heats the injured tissue, specifically the annular ring nerve fibers. Heat is applied for about 15 minutes. After healing, the disc is toughened, shrunk, and desensitized. Healing takes several weeks and pain relief is not immediate. In fact, it may increase temporarily. Although most studies to date on IDET are positive, some show no significant reduction in pain. Most studies also have flawed methods, and better research is needed to determine if and who it will help. Currently, obesity is the only factor highly associated with failure.

Radiofrequency Nerve Destruction. Radiofrequencies are being used to destroy nerves involved in the facet joints (or z-joints), which connect the vertebrae. Evidence is still weak on its benefits. A 2003 analysis suggested that it may be beneficial, however, for relief of neck pain and possibly for low back pain caused by problems in the facets joints. To date, thee have been few side effects, but some (such as serious infection) have been reported.

Nerve Blocks. A number of surgical techniques are available for relieving pain by impairing nerves that are causing pain due to impingement. In one 2000 study that used electrical stimulation to block the nerves, 60% of the patients reported at least 90% relief of pain after a year, and 87% reported at least 60% relief.

Percutaneous Vertebroplasty. Percutaneous vertebroplasty involves the injection of a cement-like bone substitute into damaged vertebrae under endoscopic and x-ray guidance. It is proving useful for stabilizing the spine and relieving pain in patients with spinal compression fractures due to osteoporosis or cancer. Success rates of 73% to 90% have been reported. Serious complications occur in fewer than 1% of cases.

Artificial Disc Replacement. Total disc replacement is an investigative procedures for some patients with severely damaged discs. The technique implants artificial discs (ProDisc, Link, SB Charite) consisting of two metal plates and a soft synthetic core. The surgery can be performed using a minimally invasive laparoscopic procedure, which is performed through tiny cuts using miniature tools and viewing devices. A study in 2003 was the first to suggest that it may eventually achieve results that are comparable to standard surgeries for disc herniation. It is still experimental, however.

An artificial cushioning device called the prosthetic disc nucleus (PDN) replaces only the inner gel-like core (nucleus pulposus) within the intervertebral space, rather than the entire disc. It, too, is showing promise in early studies.