A Spinal Fusion is a surgical technique used to join two or more vertebrae. Supplementary bone tissue, either from the patient (Autograft) or a donor (Allograft), is used in conjunction with the body's natural bone growth (Osteoblastic) processes to fuse the vertebrae.
Fusing of the spine is used primarily to eliminate the pain caused by abnormal motion of the vertebrae by immobilizing the faulty vertebrae themselves, which is usually caused by degenerative conditions. However, spinal fusion is also the preferred way to treat most spinal deformities, specifically scoliosis and kyphosis
Spinal fusion is done most commonly in the lumbar region of the spine, but it is also used to treat cervical and thoracic problems. The indications for lumbar spinal fusion are controversial. People rarely have problems with the thoracic spine because there is little normal motion in the thoracic spine. Spinal fusion in the thoracic region is most often associated with spinal deformities, such as scoliosis and kyphosis.
Patients requiring spinal fusion have either neurological deficits or severe pain which has not responded to conservative treatment. Spinal fusion surgeries are also common in patients who suffer from moderate to severe back deformities that require reconstructive surgery.
There are two main types of Lumbar Spinal Fusion
, which may be used in conjunction with each other:
Posterolateral Fusion: places the bone graft between the transverse processes in the back of the spine. These vertebrae are then fixed in place with screws and/or wire through the pedicles of each vertebra attaching to a metal rod on each side of the vertebrae.
Interbody Fusion: places the bone graft between the vertebra in the area usually occupied by the intervertebral disc. In preparation for the spinal fusion, the disc is removed entirely, for example in ACDF. A device may be placed between the vertebra to maintain spine alignment and disc height. The intervertebral device may be made from either plastic or titanium. The fusion then occurs between the endplates of the vertebrae.
Using both types of fusion is known as 360-degree fusion. Fusion success rates are higher with Interbody Fusion.
- Anterior Lumbar Interbody Fusion (ALIF ) - The disc is accessed from an anterior abdominal incision.
- Posterior Lumbar Interbody Fusion (PLIF) - The disc is accessed from a posterior incision.
- Transforaminal Lumbar Interbody Fusion (TLIF) - The disc is accessed from a posterior incision on one side of the spine.
- Transpsoas Interbody Fusion (DLIF or XLIF) - The disc is accessed from an incision through the psoas muscle on one side of the spine.
In most cases, the fusion is augmented by a process called fixation, meaning the placement of metallic screws (pedicle screws often made from titanium), rods or plates, or cages to stabilize the vertebra to facilitate bone fusion. The fusion process typically takes 6–12 months after surgery. During this time external bracing (orthotics) may be required. External factors such as smoking, osteoporosis, certain medications, and heavy activity can prolong or even prevent the fusion process. If fusion does not occur, patients may require reoperation.
Some newer technologies are being introduced which avoid fusion and preserve spinal motion. Such procedures, such as artificial disc replacement, are being offered as alternatives to fusion in the cervical spine, but have not yet been adopted on a widespread basis in the US. Their advantage over fusion has not been well established. Minimally invasive techniques have also been introduced to reduce complications and recovery time for lumbar spinal fusion.
In addition to Lumbar Fusions, Cervical Spinal Fusions may also be performed on the neck.
The purpose of a Cervical Spinal Fusion is to join certain bones in the back. Bone, metal plates, or screws can be used to make a bridge between adjacent vertebrae. In extreme cases, whole vertebrae can be removed before the fusion occurs. In most cases, however, only the intervertebral disk is removed, and the bone or metal graft is subsequently inserted, allowing for the vertebrae to eventually heal together.
Cervical Spinal Fusion can be performed for several reasons, a few that include the following:
- Following injury, this surgery can help in stabilizing the neck and preventing fractures of the spinal column which could damage the spinal cord.
- It can also be used to treat misaligned vertebrae or as a follow up for other spinal injuries.
- Additionally, cervical spinal fusion can be used to remove or reduce pressure on nerve roots caused by bone fragments or ruptured intervertebral disks.
The Los Angeles Times reported a while back about an article in the Journal, “Spine”, questioning the use of implanted hardware in spinal fusion surgeries for back problems. The Spine study found that the implantation of hardware does not improve results. The authors also determined that the hardware carries a higher risk of complications.
It is hard to offer a lot of opinions on this without seeing the study. Also, this is just one study. But in our practice in Fresno California (and throughout the Central Valley), we see a lot of herniated disc injuries and other types of back complications resulting from auto and truck accidents. Rarely does hardware seem to be a quick fix for the patient. Nor multiple surgeries, which many times do not have a better outcome than the preceding surgery.
A friend of mine had a car accident case in Los Angeles where the client is on his 8th back surgery (no prior back complaints before the car crash). I have a current client that has been involved in three rear end car accident in the last three years and has had two lumbar fusion surgeries and now needs a neck fusion due to an 8mm herniation with spinal cord impingement (no complaints prior to the first accident and he was playing basketball daily).
But that is not to say that it is not medically indicated because sometimes you would rather have a 20% chance of success than a 5% chance. (You would be amazed at how many medical malpractice calls we get claiming negligence of the doctor in performing back surgery not to mention medical malpractice in general). Unfortunately, there are often adverse results absent medical malpractice.
The good news is spinal surgery has come a long way. Not that many years ago, spinal surgery required a large incision and the patient was left in a body cast for six months to a year. About five years ago, a spinal surgeon from the University of California performed one of the first minimally invasive spinal surgeries in the U.S. using a new technique to stabilize the lumbar spine.
The procedure is called Axial Lumbar Inter-Body Fusion (ALIBF) and it has grown to be a widely accepted procedure in the United States. http://spinetreatmentcenters.com/library/procedures/axial-lumbar-interbody-fusion/
The ALIBF procedure requires only a tiny incision in the back and can have patients up and walking with little pain within hours of leaving the operating room. Absolutely incredible. Interestingly, the fusion is done in the front of the spine without having to go through the abdomen. The technique was developed 5 years ago by an interventional radiologist. The first surgeries were performed in Brazil, where 33 patients have been operated on since the technique was introduced there in 2003. The Food and Drug Administration (FDA) only recently approved the procedure for use in the U.S.
Who knows what the long term prospects for these patients will be? But many of the early returns have been very positive. Hopefully, the next ten years will provide a lot of relief for patients with chronic back pain.
It is still extremely difficult to determine from this data the settlement or trial value of an individual accident case. But seeing relative data for different types of disc injury cases does provide at least a small piece of the complex puzzle of valuing disc injury cases claims.
Any type of surgical procedure is a big deal that should be given significant consideration. WebMD has an excellent form entitled "Surgery: Questions to Ask Your Doctor?". Click here
for the Questionnaire, take a look at it and use it if you like.