Lumbar Total Disc Replacement (TDR)

The first type of artificial disk was approved by the FDA in October 2004. This is the CHARITE artificial disk from Depuy Spine, Inc. this is a significant new implant in the modern treatment of spinal problems. The disk replacement is the first motion preserving implant. The disk replacement has a high density low friction polyethylene spacer between 2 metal endplates. The design is similar to that of hip and knee replacement.

The artificial disk may offer several theoretical benefits over spinal fusion for treatment of chronic low back pain in carefully selected patients.

o Potentially a higher rate of clinical success.
o Potentially avoid adjacent segment deterioration

TDR Helping quality-of-life.

Disc replacement may help those who have suffered for years with disabling low back pain. Presently, Spinal fusion has been the treatment for disabling low back pain. The long term results may be similar between the two methods.

What will be one person's outcome with TDR.

A person must be careful, because not everyone can expect to become normal again. The FDA study with two-year follow-up showed that while the disk replacement patients had similar function of daily living, pain, and satisfaction as the corresponding fusion patients, neither group was completely relieved of their pain. 14% of disk replacement and 24% of fusion patients at two years had no improvement or deterioration of their preoperative pain.

Keep reasonable expectations.

Not everyone will be able to have complete pain relief. The challenge for the patient is to realize that complete relief of their pain may not be possible with disk replacement. Patient should decide whether to have the surgery based on the reasonable expectation of the risk of incomplete pain relief versus the potential of complete relief.

The challenge is to determine if disk replacement is appropriate for each person.

Surgeons have learned from the FDA trial and the European experience the patient selection is very important. Proper technique and placement of the artificial disk is very important also. The responsibility of the surgeon is to strictly adhere to the guidelines of the FDA study, and properly perform the procedure. This responsibility should maximize the benefit of the surgical result.

Will disk replacement become the gold standard for treatment of degenerative disk disease?

This is the big question for disk replacement. The same question was asked for hip and knee surgery in the 1970s. No one can predict the impact of TDR yet. In five years, we will be better able to answer this question.

Traditional treatment has been lumbar fusion.

Spine fusion surgery rather than artificial disk replacement has been the treatment of choice for individuals who have failed all conservative treatments including physical therapy and Cortisone injections for chronic low back pain. Spinal fusion surgery may not work perfectly. The average healing rate of lumbar fusion was 97% in our 10 year analysis of interbody cage fusions. The clinical success was 86.5% at two years and maintained at 87.8% at ten years. Spine fusion may take a longer time to heal completely (three to 24 months), and there is an increased rate of deterioration of adjacent motion segments over time. In our ten year study, 61% had radiographic changes of deterioration, and 20% with additional surgery recommended. This adjacent segment deterioration is a major concern for surgeon advising patients regarding spinal fusion.

Function of the normal disk.

The normal intervertebral disk has several functions. It is a spacer to maintain the height of the disk space and maintain the size of the foramina where the nerve root exits the canal. The disk is a shock absorber to allow the Spine to compress and rebound with activities such as jumping and running. It also withstands the pull of gravity during prolonged sitting or standing.

The jellylike center of the disk is called the nucleus pulposis. It has high water content. The outer ligamentous layer is called the annulus fibrosis. The annulus seals the disk space and resists pressure and prevents disk herniation. It is similar in function to a hydraulic shock absorber on an automobile.

The disk may be the source of pain as the nucleus dehydrates, and the disk space narrows and the annulus fails with cracks and bulging. Loss of the normal soft tissue tension may allow slipping of the spinal segments, bone spur formation, mechanical instability, narrowing of the foramina, and back pain. The disk may cause pain by disk herniation or disk degeneration without herniation.

Wear debris.

Debris is a concern with polyethylene implants of the hip and knee. It has been studied in the CHARITE artificial disk. Biomechanical testing simulating more than 10 years of use found no wear particles, so wear debris may not be clinically relevant in the TDR. Meticulous technique with implantation of the device placing the endplate prostheses parallel to one another will prevent abnormal wear and maximize the long-term result.

What are the results of the FDA Trial.

The study involved 375 patients at 15 centers across the country. The initial 71 patients were considered learning cases and not included in the final results. 205 patients received artificial disk replacement and 99 received BAK fusion cages. After two years of follow-up the clinical outcomes were very similar between the BAK fusion cages and the artificial disk replacement. In both groups pain and functional abilities improve substantially after surgery. The BAK fusion cage may not have been the best comparison because it is very difficult to assess fusion healing because of the interference in imaging of the titanium BAK cage.

What are the indications for Total Disk Replacement.

Disk replacement is not going to help everyone. Indications for potentially good candidate are:

1. Lumbar degenerative disk disease confirmed by medical history, x-rays, MRI and discogram.
2. Pain of degenerative disk disease not relieved by more than six months conservative treatment including physical therapy, injections, heat or cold, manipulation, etc.
3. The damaged disk is one of the two lower lumbar disks L4-5, L5-S1.

What are the contraindications for Total Disk Replacement.

Generally, the disk replacement is not recommended for anyone with back pain and one of the following conditions.

1. Multiple levels disk degeneration
2. instability of the spine (spondylolithesis, fracture, tumor)
3. poor bone quality, e.g. osteoporosis
4. previous major back surgery
5. patients with inflammatory arthritis of joints
6. patient with previous infection of the Spine
7. morbid obesity

Questions and Answers

How do I know if I have degenerative disk disease?

A. The diagnosis of degenerative disk disease is made on the patient's medical history of chronic severe low back pain, and imaging including x-rays, MRI, and possibly lumbar discogram. X-rays will show narrowing of the disk space. The MRI will show decreased water content or hydration of the degenerative disk. A lumbar discogram will show leakage of dye and re-creation of the patient's normal pain with the injection.

Will I need Spine surgery?

a. Rarely does degenerative disk disease require surgery. Conservative care including anti-inflammatory medication, physical therapy, exercise programs, manipulation, and hot and cold modalities, usually will restore lumbar spine health. Surgery is reserved for those with debilitating back pain that do not responded any conservative care for more than six months. Usually the painful disc and normal adjacent discs are identified by discography before surgery is recommended.

What type surgery is usually done for painful degenerative disks?

a. In general, surgical treatment is controversial because there may be other sources of pain than the degenerative disc. Lumbar spinal fusion is the standard surgery for mechanical low back pain, caused by painful degenerative disc disease. Fusion stops the motion of the painful degenerative disk. The un-fused adjacent disks must take on the motion loss by the fusion of the painful disk.

Is the artificial disk like a total joint replacement?

a. They are similar. Both have metal surfaces separated by a high density plastic piece. The artificial disk is inserted in a degenerative disk space. This restores disk height, improves spinal motion, and should decrease pain.

Cervical Disc Replacement

This is an alternative to traditional discectomy and fusion of the cervical disc. STOSSA physicians have been trained to use the ProDisc from Synthes Company.

Patient information about the ProDisc-Cervical

Why May I Need Surgery?

Your doctor has diagnosed you with Symptomatic Cervical Disc Disease (SCDD). Your doctor may call your condition a herniated disc, spondylosis or radiculopathy. Normally, the intervertebral disc between each pair of vertebrae provides the cushioning space that keeps the bones separated.  Symptomatic Cervical Disc Disease (SCDD) can occur when the discs no longer work normally because of wear or from being injured. This can cause the vertebral bodies to compress or lose height, and they may press on the nerves or the spinal cord. This can cause pain and/or numbness in the arms and neck and limit your ability to perform daily activities. 

If you have been diagnosed with SCDD and your pain has failed to improve after at least six weeks of conservative (non-surgical) treatment such as physical therapy or medication, you may get relief by having surgery.  One type of surgery is total disc replacement surgery. A Computed Tomography (CT) scan, Magnetic Resonance Imaging (MRI) and/or X-rays may be required to confirm the source of your pain and to help your doctor determine if you are a suitable candidate for surgery, including total disc replacement.

What is the ProDisc-C Total Disc Replacement?

The ProDisc-C Total Disc Replacement implant is composed of top and bottom metal (cobalt chromium molybdenum) endplates and a plastic inlay (ultra-high molecular weight polyethylene) that forms a ball and socket joint. The ProDisc-C Total Disc Replacement implant provides the possibility for motion by allowing the top endplate to move over the plastic ball attached to the bottom endplate. The materials used in the ProDisc-C Total Disc Replacement implant have been used in spinal disc replacement for over 20 years in Europe and are the most commonly used materials in knee and hip replacements worldwide.

How Is Surgery With the ProDisc-C Different From Other Surgical Choices?

ProDisc-C Total Disc Replacement surgery is an alternative to Anterior Cervical Discectomy and Fusion (ACDF), which is the surgery that is most commonly done for your condition. In both the ACDF and the ProDisc-C Total Disc Replacement procedures, the unhealthy disc is removed and the height at that level of your spine is restored to relieve pressure on the nerves and/or spinal cord.  In an ACDF procedure, after the unhealthy disc is removed, the bones are fixed in position with implants and bone graft. In some ACDF procedures, the bone graft may come from your hip in a separate incision. After surgery, the two bones are supposed to grow together, creating one solid piece of bone and eliminating motion at that level of your spine.  In the ProDisc-C Total Disc Replacement procedure, the device is inserted into the disc space to restore the height at that level of your spine, while potentially allowing some motion. The ProDisc-C Total Disc Replacement procedure does not require a bone graft.
The ProDisc-C Total Disc Replacement is used to replace one unhealthy (diseased and/or degenerated) disc of the cervical spine after the unhealthy disc is removed.  The ProDisc-C Total Disc Replacement is designed to reduce pain by removing the unhealthy disc while potentially allowing your neck to move after surgery. The ProDisc-C  Total Disc Replacement should only be used in patients who are at least 21 years of age, have only one unhealthy disc, and have had neck or arm pain for at least six (6) weeks that did not respond to non-operative care (physical therapy, medication, etc.).

Who Should Not Receive the ProDisc-C?

You should not receive the ProDisc-C Total Disc Replacement if you have any of the following:

Any type of infection, especially infection in the spine and/or surrounding area

• Poor quality bone (osteoporosis or osteopenia)
• An unstable or overly weak neck
• Allergies or sensitivity to metals (cobalt, chromium, molybdenum, and/or titanium) or plastic (polyethylene)
• Stiffening of the neck or severe degeneration
• Weakened bones at the treatment level due to past or present injury
• More than one unhealthy disc in your neck

What Warnings and Precautions Should I Pay Attention To?

It is important to select a surgeon who has attended a training course sponsored by the company who makes the ProDisc-C Total Disc Replacement (Synthes Spine, Inc.). 

This device is placed close to nerves and blood vessels in the cervical spine. There is a risk of nerve damage or serious and potentially fatal bleeding if damage to these structures occurs during or after surgery.

It is very important that you let your doctor know about any allergies you have, any medications you take on a regular basis, if you are pregnant or if have any other treated or untreated illnesses, such as rheumatoid arthritis, cancer, cardiac disease, diabetes, hepatitis, osteoporosis, previous surgeries or injuries you may have that may impact whether this device is right for you.

As with any surgery, there are some possible problems that can occur when you have neck surgery, including surgery with the ProDisc-C Total Disc Replacement.  There is a risk that the surgery may not make you feel better or may cause you to feel worse. If this happens you may need another surgery to help you feel better.  Specific possible problems that may occur include:

• Allergic reaction to the anesthesia used during your surgery
• Allergic reaction to the implant materials that may lead to implant loosening or failure
• Change in the curvature of your neck
• Death
• Difficulty or pain when you swallow
• Difficultly with or change in your speech
• The implant may not stay in place or may break, bend, loosen, or move, potentially causing pain, paralysis, or damage to blood vessels, nerves, or the spinal cord
• Pain in your neck, arms, or other parts of your body
• Numbness or tingling in your extremities
• Muscle weakness in your extremities or in general
• Failure of the device/procedure to make you feel better
• Fracture of the bones in your neck
• Seizures
• Infection (of your wound, your spine or an infection in your blood)
• Inability to move your neck at the treated level (unintended fusion)
• Development or progression of disease at other levels in your cervical spine
• Bleeding or a collection of clotted blood (hematoma)
• Blood clots in your extremities, lungs, brain (stroke) or other parts of your body
• Swelling
• Complications of pregnancy including miscarriage and fetal birth defects
• Inability to resume activities of normal daily living;

In a U.S. clinical study of 103 patients who received ProDisc-C, there were six (6) patients who did not get any relief of their symptoms and a number of other patients whose improvement was likely not significant enough for them to notice a difference. There were two (2) patients who needed additional surgery on their neck. Throughout the course of the clinical study patients reported health related problems to their physicians. Some of the most common were pain, headaches, and muscle aches. There may be other risks associated with treatment using the ProDisc-C.  Although many of the major risks are listed in this patient information brochure, a more complete list is provided in the physician’s package insert, which your doctor has received.  Please ask your doctor for more information about any additional risks possibly related to your planned surgery.

What Can I Expect During the Surgery?

During the total disc replacement surgery, you will be under general anesthesia. The surgeon will make a small incision in the front of your neck to get to your unhealthy disc. Then the surgeon will remove the unhealthy disc. The surgeon will insert the ProDisc-C Total Disc Replacement implant into the disc space.  Finally, the surgeon will close the incision.

What Can I Expect After the Surgery?

Surgery with the ProDisc-C Total Disc Replacement is considered major surgery.  As with any major surgery, you should expect some discomfort as well as a period of rehabilitation.  Your doctor may prescribe medicines to help you manage any pain or nausea you may experience.  On average, you should expect to stay in the hospital for a day or two.

After you go home

You and your doctor should talk about a plan to steadily bring you back to normal activity while the healing process occurs.  It is very important that you follow your doctor’s instructions.  You can begin moving soon after surgery, but try not to do too much, too soon.

Your doctor may recommend the following instructions:

• A hard or soft collar may be used if your doctor thinks it is necessary
• Avoid prolonged or strenuous activity
• Avoid heavy physical activity until your doctor tells you it is okay
• You will be taught how to clean and care for your wound
• You will be taught how to clean and care for your wound.

After surgery, your doctor may refer you to a physical therapist who will teach you exercises to improve your strength and mobility while protecting your spine.

Contact your doctor immediately if you:

• have a fever,
• notice fluid draining from your wound,
• have trouble swallowing or breathing,
• have trouble urinating
• have new or increased neck pain, arm pain, numbness, or weakness .
• Please be sure to tell any doctors you later see that you had surgery with the ProDisc-C Total Disc Replacement before you have a magnetic resonance imaging (MRI) taken. The metal in the ProDisc-C Total Disc Replacement can effect the quality of images taken.

What are the Expected Outcomes of the Surgery?

The U.S. clinical study of the ProDisc-C Total Disc Replacement showed that ProDisc-C Total Disc Replacement was just as good as fusion surgery in helping to relieve pain and restore normal function.  The rates of complications were about the same between the two groups in the first two years following surgery. The clinical benefit beyond two years has not been measured. Ask your surgeon for more details about the clinical study and its results.

Is the ProDisc surgery covered by insurance?

Total disc replacement is a new therapy. While some payors, such as Aetna, Cigna, Blue Cross,  and Kaiser Permanente have recognized the value of this therapy, many insurance companies are not familiar with total disc replacement and may not have a routine procedure for covering the surgery. Patients should ask their physician to request preauthorization from the insurance company before surgery. Patients can also request preauthorization, but there is often medical information that must be submitted and patients do not always have full access to their medical histories.