Lumbar Microdiskectomy
The following information will help explain what is involved when a “microdiskectomy” is performed on your lower back. We have found that the more knowledgeable the patient, the more successful the surgical outcome. The following are commonly asked questions by patients undergoing a microdiskectomy.

1. What is an intervertebral disk?
   

   An intervertebral disk is a kidney shaped structure located between each pair of vertebrae. They are designed to redistribute forces incurred by the spinal column when sitting, standing, or lifting. The normal intervertebral disk is composed of a semi-liquid substance (nucleus) surrounded by several layers of fibrous rings (annulus fibrosus). Together they form a self-contained unit.

   The intervertebral disk is strong and stable. When an object is lifted, the force is transmitted directly onto the semi-liquid center and then redistributed to the outer fibrous rings. As the force is redistributed, the rings resist deformation. It is this combination that enables the disk to act like a shock absorber.
   

2. What causes a disk to rupture or herniated?
   

   Repetitive bending and twisting and sometimes a single back injury can create a sheer stress across the disk. Over time this stress may cause the outer fibrous rings to break down, one layer at a time. Gradually, the semi-liquid center of the disk will work its way through the outer ring and push on a nerve. This is known as a disk herniation. Herniated disk, ruptured disk, and slipped disk generally mean the same thing.

   There are 5 disks in our lower back, located between each pair of vertebrae from L1 to S1. The two lowest disks, L4-5 and L5-S1, most commonly rupture. L3-4 occasionally ruptures, whereas L1-2 and L2-3 rarely do so. Depending on the level involved, different nerves may be pinched. Pressure on a nerve may manifest itself in the form of pain, numbness, weakness, tingling, or loss of a reflex. The distribution of symptoms varies depending on which nerve root is involved.
   

3. What are the main reasons for performing a microdiskectomy?
   

   There are some extreme circumstances, such as loss of bowel and bladder function, when immediate surgery is necessary. However, most disk ruptures resolve gradually without surgical intervention. The most common reason to have surgery is to alleviate pain which has not resolved within a reasonable time period. Many people would like to be more active than their pain allows and this usually persuades them to have surgery.

   Research shows that after1 year of observation, patients who have chosen surgery have significantly better results than patients treated conservatively (Weber, 1983). However, after follow-up periods longer than 4 years, both the surgical and non-surgical groups have the same amount of improvement.

   If you pain is mild or moderately tolerable we do not recommend you proceed with surgery. We also feel that numbness, tingling, or the loss of a reflex is not sufficient to indicate surgery is absolutely necessary. Weakness that causes a functional problem is another reason surgery may be recommended.

   It is important to realize disk surgery is quite effective in relieving pain in the buttocks area or pain that travels down the leg; however, it is not particularly effective in relieving back pain. Back pain is typically treated with aggressive rehabilitation. The primary reason to proceed with surgery is to relieve pain in the buttocks or leg sooner than would be accomplished without surgery.
   

4. What is the chance of a successful outcome?
   A microdiskectomy is 85%-95% successful in relieving pain in the buttocks and leg. Pain relief is typically quite rapid, although in specific instances, it may take six to eight weeks for the nerve to calm down. If a nerve has been pinched for a long time, the success rate is rarely 100% as there is usually some residual mild tingling, weakness, or pain, all of which are fairly tolerable.
   
   
5. What are the limitations of the procedure?
   Surgery is intended only to remove pressure from a pinched nerve. When a disk ruptures, a hole is created in the outer ring of the disk. During surgery, the surgeon will enlarge this hole to remove any loose material; however, there is no way to repair the hole. Even though surgery is quite effective in getting rid of buttock and leg pain, you are still left with a disk that will heal but takes time to do so. Care has to be taken to prevent undue stress to the disk during this healing period, for fear of a re-herniation.
   
   
6. What happens during surgery?
   During surgery, you are carefully positioned on a padded frame in a manner which allows the space between your vertebrae to be opened as widely as possible. A small incision is made on your back over the ruptured disk. The muscles are dissected over to the side to allow us to look at the back part of your vertebrae called the lamina. A small amount of bone is trimmed from the lamina to create a space between the two vertebrae. Some ligaments between the vertebrae will also have to be removed. Utilizing a microscope, the nerve is visualized and then retracted towards the middle of the spine. We then enlarge the hole in the disk where the rupture has occurred and try to remove any loose fragments or material within the disk space.
   
   
7. Why is a microscope used?
   The microscope allows us to make a smaller incision. It enhances our visualization by magnifying the field and providing better lighting. A microscope is simply a way of making the procedure safer and more reliable; the general principles remain the same.
   
   
8. What is the hospital stay like?
   

   Microdiskectomies are now typically done as an outpatient procedure. You check into the Seattle Surgery Center about an hour prior to surgery. You will complete some basic paperwork and a nurse will ask you about your medical history. Twenty to thirty minutes prior to surgery you will be taken to the Transfer Area where you will be interviewed by the anesthesiologist. The surgery will take approximately one hour to complete and afterwards you will be brought to the Recovery Room where you will remain for approximately one hour.

   After surgery you should have significantly less leg pain, although, your back will be quite sore. Even though the size of the incision will be small, pain should be expected as your muscles where manipulated during the procedure.
   

9. What am I allowed to do when I go home?
   We generally advise people to take it easy for the first couple days. You will be able to take care of yourself, go up and down stairs, and move around based on your own comfort level. For the first 6 weeks you should not put any unnecessary stress on your back. We have found that there is a lower incidence of complications if you are mobilized early, so we encourage you to start a walking program after you are home. You should walk for as long as is tolerable and slow enough so the pain does not flare up in your leg. The nerve is generally quite sensitive after surgery and intermittent leg pain similar to your pre-surgical pain is common. The pain should calm down quickly if you decrease your activity level. A realistic guideline to establish for yourself is to exercise for a total of 1 hour per day, under the guidance of your doctor. The exercise can be done all at once or in multiple, shorter intervals.
   
   
10. When can I shower?
    You can shower with the dressing in place, or off, the second day after surgery, depending on the advice of your surgeon. Approximately 10 days after surgery you can remove the steri-strips from the incision. We recommend you do not take a bath, swim, or get in a hot tub, for one week.
    
    
11. When can I return to work?
    Each situation is unique and should be discussed with your physician prior to surgery.
    
    
12. When do I start rehabilitation?
    

    During the first 6 weeks after surgery the nerve tends to be very sensitive. We do not recommend physical therapy in the beginning of your recovery cycle because it may cause the nerve root to flare up.

    Repetitive bending, twisting, lifting, and prolonged sitting are the most common causes of disk herniation. Therefore, we believe in preventing future problems by teaching you how to properly care for you back. A back education program includes developing proper posture and body mechanics, a strengthening and stretching program, and an aerobic exercise program. You should be aware that a long term rehabilitation program is an important part of your overall recovery process. Each physician has his own approach to rehabilitation. Your physician will prescribe a rehabilitation program based on your specific needs.
    

13. What are the major risks of this procedure?
    Infection: 0.5%-2%

    Infections may show up several months after surgery and require prolonged use of IV antibiotics. To minimize the risk of infection, antibiotics are used routinely. Occasionally, an infection may progress to osteomyelitis (inflammation of the bone marrow). Future surgeries may also be necessary.

    Dural Tear/ Cerebral Spinal Fluid Leak:
    The spinal cord and nerves are surrounded by a sac of clear fluid called the dural sac. This sac is not routinely entered. However, if the sac is inadvertently torn during surgery, it is sewn tightly together to prevent any cerebral spinal fluid from leaking. Small tears require no further treatment. Larger tears may require you to remain flat on your back for 24 to 72 hours to enable the leak to seal. If the leak persists you may require further surgery or special drains.

    Nerve Damage (rare):
    In rare instances, the nerve may be damaged due to excess traction or direct trauma. Symptoms include numbness, weakness, and/or pain to the part of the body the nerve supplies. Nerve damage is usually a temporary problem (lasting 6 to 12 months) which is isolated to only one nerve. Occasionally, multiple nerves may be involved and/or the nerve may be damaged permanently. In rare instances bowel and bladder function may be lost.

    Operating at the Wrong Level:
    The most common complication of a microdiskectomy is operating at the wrong level. This risk can be minimized by intra-operative x-rays but may still occur despite all precautions.

    Lack of Pain Relief: 10%-15%
    Sometimes surgery simply does not provide satisfactory relief or pain. We suspect the nerve has been damaged by pressure and the problem can not be solved with surgery. Occasionally there is a retained fragment, such as residual disk material, pressing on the nerve. A second operation may be necessary to remove the material.

    Re-rupture: 5%-10%
    As stated earlier, there is a permanent weakness in the disk which may not heal perfectly. It is also not possible to remove all the fragmented material from the inside the disk. About 10% to 15% of patients will re-rupture additional disk material through the same hold and develop identical problems. This can occur many years later.

    There is also a group of patients who will develop a chronic aching pain in their back. A fusion may be necessary to resolve this pain. Other treatment methods are available which should be discussed with your surgeon.
    

    Reactions to Anesthesia:
    Those risks need to be discussed with your anesthesiologist.
    

14. What are some of the less serious risks of surgery?
    Complications which are less serious include bladder infection, kidney infection, superficial wound infection, superficial incision breakdown, inability to urinate, temporary increase in leg pain, nausea, headaches, reactions to medication, and constipation. As with any surgery, unanticipated complications may occur which have not been mentioned. Some complications have the potential of becoming a significant problem. These less serious risks should be considered when deciding whether to undergo a surgical procedure.
    
    
15. What is your overall philosophy regarding spine surgery?
    We recommend you have surgery if your symptoms are disruptive to your quality of life and there is a specific anatomic lesion that can be corrected. However, if your symptoms are tolerable or we cannot find a specific structural problem causing your pain, surgery is probably not a good idea. It is our role to define whether or not there is a structural lesion that can be corrected. However, only you can determine if the pain and discomfort you are experiencing is worth the risk of surgery.
    
    

Final Comments
This letter is intended to answer questions, but do not hesitate to ask as many questions as needed to get a clear picture of the procedure and options available.