Open Lumbar Spinal Fusion

David M. Pagnanelli, M.D.

The word fusion means, the merging of different elements into a union, as in two different vertebrae. In this surgery, we are trying to get two or more vertebrae to meld together and function as one. Technically, the actual fusion of bone to bone takes several months. Therefore, we often place some type of hardware (screws and rods) to hold the bones together until the actual bone fusion takes place.

The fusion may be accomplished through the same incision as a laminectomy, or through smaller incision on each side of the midline.

The general indications for a fusion are, slippage of one vertebra on another, severe degeneration of a disc, instability probable after a boney decompression, or abnormal motion at a disc level that is felt to be the source of incapacitating back pain. The patient may have one or more indications.

Indications and diagnosis

The most common type of spine fusion is performed for mechanical low back pain. This type of mechanical low back pain occurs with increased activities and oftentimes is associated with advanced degenerative changes in the discs (such as degenerative disc disease). At other times it may be due to a low-grade slippage of the spine (such as degenerative spondylolisthesis and isthmic spondylolisthesis). The most important factor in treatment of these types of low back pain is the appropriate diagnosis.

When considering the indications for lumbar spine fusion, severe low back pain that lasts for more than six months is the most general indication.

Procedures for Lumbar Spine Fusion

Posterior Fusion – Open Procedure

An incision is made in the middle of the back overlying the vertebrae to be fused. The muscles are elevated off of the bone to expose the spinous processes, laminae, facets and transverse processes on both sides.
1. The posterior fusion is often carried out along with a lumbar laminectomy, in which the spinous processes, laminae, and a portion of the facets are removed to take pressure off the lumbar nerve roots.
2. The surface of the remaining exposed bone is partially removed to expose the inside of the bone for better fusion.
3. The bone that was removed for the laminectomy is mixed with bank bone (taken from a bone bank), along with a bone growth enhancer called Demineralized Bone Matrix (DBM) or Bone Morphogenic Protein (BMP)
4. This mixture will be used later with the interbody graft

One of the factors that decrease the chance of bone fusion is motion at the fusion site. If there is instability present such as seen in cases of spondylolesthesis, eliminating motion by binding the two vertebrae together increases the chance of a good fusion--This is the function of a pedicle screws. A specially designed screw is inserted through the center of the pedicle and anchored into the body of the vertebra. This is done on both sides and in all the vertebrae to be fused. The screws are then bound together by attaching a rod to each screw head. This construct is usually made of titanium.

The accuracy of inserting the pedicle screws is greatly enhanced by live X-ray guidance.

Using Preformed Bank Bone as the Interbody Graft

	In order to provide a surface for bone to create a boney fusion, an interbody graft is placed. This may be made of titanium, steel, synthetic plastics, or bone from a bone bank that has been processed for this purpose.

Lost disc height is restored when the graft, packed with bone is inserted into the space between the two vertebrae. Basically what happens is the bone, which has been neatly packed into and around the graft, begins to grow through the perforated walls of the graft material, eventually forming a solid bond (or 'fusion') holding the vertebrae together. This process is known as 'interbody graft. The end result is fusion, a strong and stable construct. However, in spite of these efforts, not everyone will form a solid fusion. Smoking tobacco reduces the chance of fusion by as much as 50%. Diseases such as osteoporosis, diabetes, and others decrease the chance of fusion. And, even with no particular reason, some patients simply do not fuse.

Minimally Invasive Lumbar Fusions

I do nearly all of my lumbar fusions using a minimally invasive technique. (link to “Minimally Invasive Lumbar Fusion”)

Will I lose mobility once a portion of my spine becomes solid bone?

It depends in part on how much of the spine is fused. The spine will not move as much but you will not notice it, as it is only a small amount at each individual level. Most people believe that the spine enables you to bend over at the waist; this motion actually occurs mostly at the hips. There are patients that have their entire spine fused yet are still able to touch their fingertips to the floor.

Smoking

Research shows that the healing rate is greater than 90% in non-smokers and less than 50% in smokers. Many surgeons frown on performing a fusion in patients who smoke because of the higher rate of non-union and infection. Physicians have also found that in smokers it is sometimes necessary to go in through the front and the back of your spine in order to obtain a successful fusion. If you smoke, be prepared to discuss the situation in detail with your physician.

Possible Complications:

In addition to the Risks and Possible Complications of Spinal Surgery outlined previously,

• Significant complications can accompany a lumbar fusion.
• Tear in the covering of the nerves with leaking of cerebrospinal fluid
• Injury to blood vessels
• Injury to bowel or ureters
• Pseudoarthrosis- failure of the fusion to take place. Successful fusion may not be able to be determined for over one year
• Prolonged ileus, a condition in which the bowel stops functioning
• Pain from the bone graft donor site; if it is necessary to take bone from the hip.
• Dislodgment or backing out of the implant (screws and rods)
• The possibility of unforeseen complications

Lumbar fusion is generally an elective surgery. Therefore it is your choice to proceed based on your current level of discomfort and disability. We recommend that you do not have surgery if you can live with your current level of pain or can make changes in your lifestyle to decrease the pain. If you make a valiant effort and the pain still persists, surgery can be your next step.
The rate of surgical success varies greatly depending on your exact problem, overall health, and the magnitude of surgery necessary. I hope that by providing you with as much information as possible about the surgery, you can determine if the pain you are experiencing is worth the risk of surgery.

Immediately After Surgery

Pain Control – You can expect pain after surgery. We will make every reasonable effort to keep you comfortable.

Eating - For most surgeries involving the back part of the spine, patients begin drinking clear liquids the night of surgery. In the following days your diet will be advanced appropriately.

Walking - Unless specifically instructed, you should plan on getting up and walking the day after surgery. Physical therapists and the nursing staff will help you. You may require a walker at first to keep your balance safely. As soon as you don't need the walker, you can walk on your own. Plan on walking three times a day, increasing the distance as you are able.

Bowel Movements - Since the bowels are slowed by surgery and some of the pain medicine, it takes time to get them going again. You will be placed on a daily stool softener pill, and you may be given a suppository to help get things going. Things which you can do to help your bowels awaken quicker include sitting up in a chair several times during the day, and going for at least two walks a day. The more you are up, the faster you will get back to a normal bowel schedule.

Length Of Hospital Stay - Most patients are ready to go home from 2 - 4 days after surgery, depending on what was done in surgery and your general health.
Going Home or to a Rehabilitation Center? - When you are ready for discharge from the hospital, a decision will be made as to your immediate needs. If the hospital's physical therapist considers you independent, or if you have help at home, you will be released to go home. A visiting nurse or therapist may be requested by your physician to visit you at home on a daily basis for a few weeks, if it is covered by your insurance plan. For patients who still require additional therapy before they are independent, or for those without any help at home, discharge to the rehabilitation center or skilled nursing unit may be appropriate. At the care center, the focus will be on physical therapy and becoming independent.

THE FIRST TWO WEEKS AFTER SURGERY

1. Avoid lifting objects over 10 pounds until further notice.

2. Keep your sitting to a minimum, especially in the first four weeks. Try not to sit for more than 30 minutes at a time -- either walk, stand or lie down for at least 30 minutes before sitting again. When you do sit, make sure the seat is firm and has a good back support. Many people find rockers and recliners to be comfortable.

3. You may ride in a car as a passenger to go home from the hospital. Thereafter, only ride as a passenger if your back doesn't hurt. If you have to travel a long distance, recline your seat back, or lay down in the back seat. You should also stop for about 10 minutes each hour so that you can walk around and stretch your back. You may be able to drive a car about 2 weeks after discharge from the hospital.

4. Refrain from sexual relations for at least 2 weeks after your discharge from the hospital.

5. Do not exercise, unless your doctor advises otherwise. However, we do want you to walk, as much as you find comfortable. The more you walk, the better your recovery.

6. Take showers, not tub baths, for 3 weeks after your discharge from the hospital. You may find it helpful to sit in a chair while you shower. Don’t try to cover your incision. You do NOT need to cover the incision. The little tapes on the incision will fall off in time.

7. Squat to pick things up or to wash yourself in the shower; avoid bending from the waist.

8. Do not move suddenly and twist your back.

9. The narcotics can cause severe constipation. It is important for you to move your bowels regularly and without straining. Use a bulking agent or laxative if necessary. You should be taking a stool softener as long as you are on a narcotic pain medication. If you are not on medication for constipation, call this office or your primary care doctor and get some.

10. Get your prescriptions filled upon discharge, and take the pain medicine only as needed to avoid becoming dependent on it. These are powerful drugs and are addicting.

11. If given an ice machine, you should use it for pain control at home for the first 2 weeks. Use the iceman for 20 minute intervals, at least 4 times per day.

12. Sleep on a mattress that is comfortable to you. Use a bed board under your mattress if necessary, and try propping your legs up on some pillows. Many people find sleeping in a recliner best for them. Don’t worry about laying on your incision, its more important that you’re comfortable.

13. Wear flat shoes with good support for the first several weeks. A one or two inch heel is permissible.

14. You can expect some tingling or pain in your leg, if it was present prior to surgery. You may even get sharp pains as before surgery. This should resolve in time. The nerve is unlikely to completely heal in just a few days

Our office hours are Monday through Friday from 8:30 AM to 4:30 PM. We ask that you call between these hours with your questions, concerns, prescription refill requests, etc. As a surgeon, I am frequently in the operating room and therefore unable to be available during all office hours.

Prescriptions

All prescription refills and changes must be requested during office hours. We advise patients to monitor their need for refills so that refill requests can be made during your office visit.

Emergencies

We understand that emergencies arise. If you feel that it is absolutely necessary to speak with your doctor during non¬-office hours, our answering service is available, by simply dialing our office telephone number listed below. We ask that this service be reserved only for emergencies.

Office Phone 580-531-4600