Artificial Disc Replacement for the Treatment of Degenerative Disc Disease
Degenerative disc disease with low back pain is among the most common reasons for disability among adults. Many patients respond to conservative, non-surgical treatment including physical therapy, lumbar bracing, medication, and spinal injections. When this does not work, patients may be referred for surgical intervention.
Patients with degenerative disc disease now have a choice in surgical treatment. Traditionally, surgeon's options were limited to fusing the affected area of the spine to limit motion and thus reduce pain. In October of 2004, the Charite Artificial Disc (DuPuy Spine) was approved by the PDA for use in patients with single-level degenerative disc disease. This is a high-tech device made of metal and pliable plastic that replaces the diseased disc and allows patients to maintain flexibility. It is the first "motion preserving alternative to lumbar spinal fusion surgery," explains Robert Ho, M.D., clinical assistant professor of neurosurgery at Wayne State Medical School. Dr. Ho has been specially trained in using the Charite Artificial Disc.
Advantages of Disc Replacement Surgery
There are several advantages of disc replacement surgery over spinal fusion surgery. While lumbar spinal fusion surgery is often effective in reducing pain, the surgery puts additional stress on the remaining mobile segments that may lead to adjacent segment degeneration and a recurrence of symptoms. The artificial disc design preserves motion and allows patients to maintain flexibility. In the clinical study, patients were observed to have motion between 0 and 21 degrees in flexion and extension (bending forwards and backwards).
Generally, the post-operative recovery and return to activities and work is faster with the artificial disc than with traditional spinal fusion surgery. In our practice, we typically have our lumbar fusion patients wear a rigid back brace for approximately 4-6 months while the fusion site heals. The limits range of motion, specifically bending forward and backward, as well as rotation of the lumbar spine. Physical therapy begins after the brace is removed to restore strength and motion to the lumbar spine. In contrast, with artificial disc replacement surgery, active rehabilitation begins in 3-6 weeks.
Another benefit to disc replacement surgery is that no bone graft is required. When a spinal fusion is performed, bone is taken from the iliac crest for the fusion. This means that the patient has two incisions that must heal as well as pain in the hip and back during the recovery period.
Who is a Candidate for Artificial Disc Replacement Surgery?
The lumbar artificial disc is an alternative to spinal fusion surgery. Its purpose is to maintain the basic motion of the disc, thereby protecting the adjacent discs against the increased stress that is present with fusion.
- Age 18-60 years
- Degenerative disc disease at one level, between L4 and L5 or between L5 and S1. Degenerative disc disease is defined as a disc that has worn out or becomes injured and causes back pain
- Patients have failed at least 6 months of treatment such as pain medication, physical therapy, facet joint injections, and epidural steroid injection therapy.
- Mechanical back pain at the operative level determined by provocative discogram. This is a diagnostic test that pressurizes the disc in question. A normal disc will not cause pain. An abnormal or degenerated disc when pressurized, will replicate the patient's pain pattern.
Who is Not a Candidate for Artificial Disc Replacement Surgery
- If you have disc degeneration at multiple levels in the lumbar spine
- If there is instability in the spine from spondylolysis or spondylolisthesis. This is a condition where one bone has slipped over another, producing instability
- If you have poor bone quality from osteoporosis or osteopenia
- Morbid obesity, defined as more than 100lbs over ideal body weight
- Pregnancy
- Certain spinal conditions such as scoliosis, spinal tumor, infection, or previous spinal fractures
- Metal allergy
- Multiple abdominal surgeries, usually greater than three
Surgical Approach for Artificial Disc Replacement
When undergoing disc replacement surgery, you will be lying on your back and the surgeon will operate on your spine through an incision near the belly button. During surgery, the surgeon will remove the diseased disc and replace it with the artificial disc.
Possible Complications of Artificial Disc Replacement Surgery
As with any surgery, there are possible complications that can occur when you have disc replacement surgery. Any surgery, no matter how minor or major, carries with it an element of risk. The following list of complications is included for you to discuss with your surgeon, so you will be able to make the best decision. If you have and concerns, we encourage you to speak frankly with your doctor before agreeing to surgery. Sharing your concerns and resolving reasonable doubts will contribute to your peace of mind and ultimately help you choose the best course of action. Complications in general include, but are not limited to:
- Bleeding, which may require a blood transfusion
- Infection, which may require removal of prosthesis
- Pain or discomfort
- Allergic reaction to the implant materials
- Slow movement of the intestines
- Spinal cord or nerve damage
- Paralysis
- Implants that bend, break, loosen or move
- The need for additional surgery
- Bladder problems
- Side effects from anesthesia
- Incision problems, such as hernia
- Retrograde ejaculation or impotence. This rare complication may occur in men undergoing any deep abdominal surgery. Retrograde ejaculation causes the semen containing sperm to be ejaculated in a retrograde fashion, thus rendering the male infertile. This may be of consequence in males who desire children. Impotence may occur due to nerve injury during the anterior exposure.
- Decreased sensitivity in women 2
- Problems with your blood vessels, such as inflammation (phlebitis), blood clot (thrombophlebitis) or pulmonary emboli (blood clot breaks off and travels to lung
- Stroke
- Death
General Postoperative Guidelines and Rehabilitation with an Artificial Disc
Early ambulation is vital to the overall success of the surgery, and limits the incidence of postoperative complications
Early rehabilitation (0-3 week's post-operative) is initiated. Walking is
encouraged. Flexion (forward bending) is allowed. No lumbar rotation for at least 3 weeks, no extension (backward bending) for 6 weeks.
Post operative physical therapy program initiated approximately 3 weeks following surgery
Limit abdominal exercises until after 6 weeks to allow incision to heal. Return to sports and high level activities should only take place after consulting with the surgeon three months postoperatively.
