Surgery

Diskectomy is the surgical removal of the diseased disk. The procedure relieves pressure on the spine. It has been performed for 40 years with increasingly less invasive techniques being developed over time. However, few studies have been conducted to determine its real effectiveness. In appropriate candidates it provides faster immediate relief than medical treatment, but long-term benefits (over 5 years) are 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 called a slipped disk. Most slipped disks (herniated disks) take place in the lumbar area of the spine. Slipped disks are one of the most common causes of lower back pain. The mainstay of treatment 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 may be needed.

Microdiskectomy. Microdiskectomy 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 disk 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 Diskectomy. 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 Diskectomy. Percutaneous diskectomy (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 Diskectomy. 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 these less-invasive procedures are any more effective than the standard microdiskectomy.

Complications and Outlook. Many patients still have back pain after diskectomy 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 3 or 4 days after disk surgery. It may take 4 to 6 weeks for full recovery, however. Gentle exercise may be recommended at first. Starting intensive exercise four to 6 weeks after a first-time disk 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.

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 cases where 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 uses 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 2 years, compared to 7% who received conservative treatment with physical therapy. Pain improved most in the 6 months following surgery. However, a 2005 clinical trial found that spinal fusion surgery worked no better than intensive rehabilitation in reducing disability. The intensive rehabilitation program included both physical and cognitive-behavioral therapy.

Many spinal fusion surgeries use a tiny hollow metal cage, which is implanted into the disk space. Bone is then removed from the patient's 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. The new techniques 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

Intradiskal Electrothermal Treatment (IDET). Intradiskal electrothermal treatment (IDET) uses electricity to heat a painful disk. Heat is applied for about 15 minutes. Pain may temporarily feel worse, but after healing, the disk shrinks and becomes desensitized to pain. However, healing takes several weeks. The surgery may not work in obese patients.

Some studies have reported positive benefits to IDET; others say it does not significantly reduce pain. A randomized, blinded study published in the November 2005 journal Spine found that IDET was no better than a sham (fake) procedure in relieving chronic back pain due to problem disks. For the study, patients were randomly selected to receive either IDET or a sham procedure. After 6 months, there was no difference in pain symptoms between the two groups.

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. Serious infections 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. Medical research has shown that 60% of the patients who received electrical stimulation to block the nerves reported at least 90% relief of pain after a year; 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. A Mayo Clinic study found that patients who have the procedure have less back pain during rest and activity. A survey of records from more than 100 vertebroplasty patients revealed that most patients are more functional than before the procedure, and the benefits lasted for up to a year. Warning: The FDA has warned consumers that polymethylmethacrylate bone cement, used during vertebroplasty could leak. Such leakage could cause damage to soft tissues and nerves. It is extremely important that the patient is sure that the surgeon has had significant experience performing the vertebroplasty procedure.

Artificial Disk Replacement. Total disk replacement is an investigative procedure for some patients with severely damaged disks. The technique implants artificial disks (ProDisk, Link, SB Charite) consisting of two metal plates and a soft 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 disk herniation.

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

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Review Date: 4/26/2006
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital