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ARTIFICIAL LUMBAR DISC REPLACEMENT. The Charite artificial disc is available through the Johnson & Johnson-DePuy Company with FDA approval. The device consists of two metal endplates and a polyethylene core. This device is FDA approved for treating low back pain only, and limited to the L4/5 and/or the L5/S1 disc levels. All the physicians at LDR Neurosurgery have taken the additional training for placement of these artificial lumbar discs at the Johnson & Johnson training center. To date, we have not done a single case for the following issues noted below.
The procedure is done anteriorly (eg, though an incision in the abdomen). The disc causing the back pain removed and the artificial disc inserted. The procedure is generally done by a neurosurgeon or orthopedic surgeon trained in spinal surgery, with an access surgeon (for the abdominal dissection) who is usually a vascular surgeon. The artificial disc has to be perfectly positioned or there are problems with the spinal movement which can translate into a poor outcome with ongoing back pain, etc.
The device may, in some patients work quite well, however there are potentially significant complications with this procedure. If the polyethylene core or either of the metal endplates become dislodged into the abdomen (eg, spit out) then the major blood vessels directly in front of the spinal column become immediately compressed which can cause poor blood flow into the legs, or prevention of blood returning from the legs though the major vein in the abdomen (the inferior vena cava) which could produce a blood clot into this large vein that could travel into the heart and lungs. This can be a life threatening problem. Surgical revision of this device, under this scenario, can be LIFE THREATENING as well. To remove the device which is now surrounded by scar tissue and to dissect off the very thin walled large vein and the artery can result in massive bleeding and death.
There have been surgeons who have given up the procedure due to this complication. As well, no one knows how long this device will last. If they are not perfectly placed, or if they do not do the job they intended to be done, then a posterior fusion (back of the spine) is performed with pedicle screws (large screws into the vertebral bodies) above and below the implant. Bone is then laid down over the back of the spine to then produce a posterior spinal fusion with the implant being left in position. Many insurance companies will not pay for the device as the insurance companies do not believe in this technology and thus will not authorize the placement of the devices.
Due to the above, we feel that this procedure, at least with the current technology, is too dangerous of a procedure. Perhaps if there are refinements or further developments with this device, or other devices in the future, we may perform a artificial disc replacement, but at least at this time we feel this is too dangerous of a procedure for the above reasons. For additional information on the Internet:
Website #1 & Website #2
ARTIFICIAL CERVICAL DISC REPLACEMENT: The Medtronic Prestige Cervical Disc has been approved by the FDA for use in patients to treat cervical nerve root or spinal cord compression. It is not FDA approved or recommended to be used by Medtronic for treatment of neck pain. The device can easily be inserted after the cervical nerve root and/or spinal cord have been decompressed. It is secured in place by screws that are placed into the vertebral body above and below the disc space. The surgeons at LDR Neurosurgery have taken the additional training through the Medtronic training centers. However, to this point, we have not done a single cervical disc replacement surgery (see below).
The problems with the design of this implant is that it is made out of stainless steel. The stainless steel is strong and may work well for the purpose intended, however, if a patient ever were to need a MRI scan of the cervical spine, the stainless steel will cause artifact on the scan that would make it unreadable. As a result, if a patient were to have this device implanted and then develop a cervical spine problem at, or above, or below the level of the implanted device then due to the metal artifact on the MRI scan it will make reading the scans difficult if not impossible. Also, the large flanges that extend over the vertebral bodies anteriorly that are fixed in with screws make it difficult or impossible to treat a cervical spine problem at the level above or below the site of placement of the artificial disc. This is due to the large flanges over the bone which prevent another artificial disc being placed above or below and also would prevent placement of a fusion plate immediately above or below the artificial disc. What this could mean is that if there was adjacent spine disease that needed surgery in the future the artificial disc may have to be replaced with a fusion device. Thus, it makes any further evaluation and treatment difficult. In the next year or two there may be made available titanium artificial discs which may help with the interpreting MRI scans after placement of a titanium disc. Depending on the design, however, it may not eliminate the issue with the flanges and further surgery at a adjacent level.
Therefore, at least at this time, we do not feel this is a good design for the artificial cervical disc. With improved design and materials future artificial cervical disc replacement may prove to be superior to a fusion operation. For additional information on the Internet:
Website #1 & Website #2 .
There are other sites as well.
THE X-STOP: The X-Stop is a titanium device that is used as a spacer between the spinous processes in the back for treatment of the symptoms of neurogenic claudication from lumbar stenosis. In other words, the device separates the spinous processes from the very back of the spine, stretches the ligaments inside the canal where the nerve groups pass, and then in theory take the pressure off the nerves inside the spinal canal. The LDR group has taken the additional training in order to insert these devices. We have inserted a couple of these devices, but without good results. One case the spinous process fractured after two weeks which required a small open operation. The other case never really improved.
The device costs to the hospital are around $5,000 for the implant alone, and if two levels are done, then double that figure. It is out opinion that a very small, limited bone removal on one side of the spine will open up the spinal canal and decompress the nerve elements. This has a very high probability of significant long term improvement of the compression of the nerve root sac in the back. In addition, there is no implanted device that could fail with a reproduction of the same symptoms.
Thus, it is our opinion that this device has only limited application and a higher potential for failure than the gold standard operation of a limited bone removal over the nerve root sac in the spine. For additional information from the X-stop company see the following web site:
Website #1 & Website #2 .
LASER DISCECTOMY: A laser discectomy is one in which the burning force of the laser is used to burn away disc material to remove a herniated lumbar disc. This procedure requires the same bony opening done in a conventional lumbar discectomy, thus no change from a conventional approach. The difference being that the laser is used to burn away the disc once the open operation has been performed. Conventional instruments used to grasp the disc, or scrape some of the disc out of the disc space works quite well without the effect of burning the tissue. Once the tissue surrounding the disc has been burned by the laser there is, in our opinion, a higher chance of causing a disc space infection and inflammation in the bone, which could lead to long term antibiotic use, additional pain and no advantage to conventionally removing the disc material. Thus, in our opinion, there is no advantage to the lumbar laser discectomy and perhaps some additional risks to the procedure. We have not performed this operation for these reasons.
KYPHOPLASTY: A Kyphoplasty is a procedure to treat osteoporotic compression fractures. There is a similar procedure called a Vertebroplasty. Both procedures accomplish similar results with similar indications. The Kyphoplasty is, in our opinion, a better procedure. It is a technique where, under general anesthesia, two needles are inserted into the fractured vertebral body. A balloon is inflated inside the fracture and then the balloon is deflated. This creates a empty space in the vertebral body. After this is done, passive injection of methylmethacrylate is injected into the vertebral body which fills up the empty cavity and the spaces inside the vertebral body. The methylmethacrylate hardens in a few minutes inside the compressed vertebral body. This procedure strengthens the vertebral body against further compression fractures which helps to reduce the pain and improving the height of the vertebral body. We feel this is an excellent procedure for treating osteoporotic compression fractures. Without such a procedure, further compression of the vertebral body can occur which could cause compression of the nerves and spinal cord in the spine or develop a progressive kyphotic deformity (angulation of the spine) at the level of the fracture. As a result of a change in the dynamics of the weight distribution on the spine, the spine is then a set up for additional compression fractures. Visit these websites for additional information:
This last image demonstrates the methylmethacrylate after injection into the cavity created by the balloon.
GAMMA KNIFE: The PERFEXION Gamma Knife Unit has been installed and is being used at San Antonio Community Hospital. This is a non-surgical radiation therapy for brain tumors, certain vascular abnormalities, trigeminal neuralgia and some movement disorders. Additiional information can be obtained at http://www.irsa.org/ (International RadioSurgery Association). This is available at San Antonio Community Hospital. Dr. Lederhaus, Dr. Rodriguez, Dr. Disney and Dr. Amirnovin are certified GAMMA Knife operators. The Website for the SACH Gamma Knife Center: http://www.sach.org/asp/Site/ProgramsAndServices/Gamma/index.asp
|Last Updated ( Tuesday, 04 August 2009 )|