Artificial Disc Replacement

T. Sunil Thomas, MD
Spine & Orthopedic Surgery
Eau Claire Spine & Orthopedics
Eau Claire

Low back pain due to “worn out discs” or degenerative disc disease in the lumbar spine is a common condition affecting a large segment of the population. Patients with this condition are treated non–surgically with anti-inflammatory medications, physical therapy, epidural or cortisone injections, and lifestyle and activity modifications. Most patients respond favorably to this type of non-surgical treatment, but a small number of patients will continue to experience pain and significant functional limitations. For these patients with ongoing low back pain due to degenerative disc disease, surgical treatment in the form of lumbar spinal fusion (knitting of the bones together) has been the preferred surgical treatment.

Artificial disc allows flexibility and movement similar to one’s
natural spine.

The spinal column is made up of bones (vertebrae) and discs which alternate with each other in a repetitive fashion. The discs are the soft tissue structures in between the vertebrae and function as cushions or “shock absorbers” and also give stability and motion to the spinal column. The disc is made up of an inner jelly-like substance consisting predominantly of water and proteins (nucleus) and an outer fibrous covering (annulus fibrosis). As normal aging progresses, the disc looses its water content and can develop tears. The deteriorating disc starts to lose its function of cushioning and stability and can give rise to low back pain (degenerative disc disease). This type of scenario can also occur earlier in life from injuries to the low back and in some cases can be hereditary.

Disc is composed of two cobalt chromium end plates
and a polyethylene core. (Images provided courtesy of DePuy Spine, Inc. Copyright 2006)

Spinal fusion surgery does have its drawbacks. First, the bones have to grow (fuse) together and in about 10-15% of patients the fusion does not take and can lead to ongoing symptoms and necessitate further surgery. This is a particular problem for smokers undergoing fusion surgery. Second, the surgery does not completely alleviate all the pain (60-80% pain relief). Third, the fusion causes stiffness and decreased range-of-motion which can lead to increased stress on the adjacent unfused segments of the spine. In an effort to avoid some of the drawbacks associated with spinal fusion, research was directed towards non-fusion or motion sparing technology such as artificial disc replacement.

Artificial Disc Replacement is a procedure where all or most of the disc tissue is removed and replaced by an artificial disc made of metal and plastic. These materials are the same as those used in artificial hips and knees. There are several different designs available on the market and at this time there are two manufacturers that are approved to market artificial discs in the United States. Disc replacements have been used in Europe since the late 1980s and have a good track record in the European literature. The artificial disc replacement surgical procedure is currently offered in the Chippewa Valley by Dr. Sunil Thomas, Eau Claire Spine & Orthopedics.

Are you a candidate for artificial disc replacement?

The key to the success of artificial disc replacement is patient selection. This includes a thorough history and physical examination and appropriate testing to identify the exact source of the patient’s low back pain. There are several conditions that may prevent a candidate from receiving an artificial disc, including spondylolisthesis (slippage of one vertebrae across another), osteoporosis, fractures or tumors of the vertebrae, infection, morbid obesity, or pregnancy. Since the disc is inserted from the front (through the abdomen), prior abdominal surgery or problems with the blood vessels in front of the spine, may prevent disc insertion.

As with any new technology, the long term results and potential complications associated with artificial disc replacement in the U.S. are not fully known at this time. Possible complications include infection, dislodgement or breakage of the device, wear of the artificial disc materials, damage to the blood vessels or nerves, failure to resolve the pain or development of new pain.

The surgical treatment of degenerative disc disease to date has been spinal fusion and continues to be the surgical procedure against which all new technologies will be compared. Artificial disc replacement does offer a new and promising option to consider in the surgical management of degenerative disc disease of the lumbar spine.

For more information or to schedule an appointment with
Dr. Thomas, Eau Claire Spine & Orthopedics, call 715-858-0320.
Dr. Thomas also sees patients in St. Croix Falls and Rice Lake.

For more information or to schedule an appointment with Dr. Thomas, Eau Claire Spine & Orthopedics, call 715-858-0320.
Dr. Thomas also sees patients in St. Croix Falls and Rice Lake.