Results of Double-Level Posterior Spine Fusion

Posterior lumbar interbody fusion (PLIF) is often used to fuse the spine. Patients with degenerative lumbar diseases with pain and instability are often treated with PLIF. Most studies report the results of single-level PLIF. This study from Japan reports the results of double-level PLIF.

Nineteen (19) patients were followed for at least two years. Everyone had two levels of the lumbar spine fused. Measures of success included improved pain, increased activity, and improved lumbar lordosis.

Lordosis is the angle of the bones forming the curve of the lower spine. Decreased lordosis means the back is flat. A curved low back occurs with increased lumbar lordosis. A flat back increases the pulling load on the spine causing pain. That’s why getting the right amount of lordosis is important.

In this study double PLIF had good results that were maintained for two or more years. The researchers report the unfused segments even tried to adjust to the fusion in an effort to keep the normal lumbar lordosis.

The authors also say the double-level PLIF didn’t have as good of results as a single-level PLIF. The difference may be because patients with degenerative disease at more than one level also have other problems. There was more neurologic damage. Almost half of the patients in this study also had arthritis affecting their knees.

Overall the results of the double-level PLIF were reported as “satisfactory.” The operation is considered invasive based on the amount of blood loss and how long the operation takes.

Doctors Review Nucleus Pulposus Implant

Spinal surgeons are looking to disc replacements as the next possible step in treating chronic pain from disc degeneration. For the past 40 years spinal fusion has been the best medicine had to offer for chronic back pain from disc degeneration. Over half a million adults had spinal fusions in 2005.

But there are many problems with spinal fusion. New treatment methods are needed. Disc implants to replace the aging, worn out inner disc called the nucleus pulposus are being tested now. Doctors from Thomas Jefferson University Hospital in Philadelphia reviewed the history of disc implants. The results are reported in this article.

A major advantage of the disc implant is that it saves motion in the spine. A fusion stops motion at that level and increases the load on nearby segments. The disc implant also keeps the normal disc height, which relieves pressure on the joints and ligaments.

The disc must be able to last over 40 years. It will need to withstand the forces of 2 million strides per year in the average adult. It must be designed to resist fatigue, fracture, or too much swelling. It must stay in place but allow movement of the spine.

Right now nucleus pulposus implants are still under study. The authors say they are “experimental.” The big question is whether these implants can function like a human disc. They must be flexible but strong enough to take loads at different rates from different directions. Long-term studies are needed to see how they hold up over the years.

Is IDET Safe and Effective for Low Back Pain?

At the turn of the century (2000) a new way to treat chronic low back pain (CLBP) caused by disc disease was introduced. It was called intradiscal electrothermal therapy (IDET). Early studies of this heat treatment put directly into the disc were promising. Later results were more conflicting with risks more clearly defined.

The authors of this study compare a group of CLBP patients who got IDET to a group with the same symptoms who had a placebo (sham) treatment. No one (except the person applying the IDET) knew which patients were in each group. Each person followed a Pilates-based exercise program.

Everyone was seen again at six weeks and at six months after the treatment. Measures of success included pain relief, increased activity level, and the ability to sit. Use of medications, ability to work, and any neurologic signs were also recorded.

The researchers set the standard for success based on these measures. No one in either group met the standard. In other words, there were no success stories. The authors concluded there was no difference between the two groups.

IDET may be a safe treatment bit it has not been proven consistently successful. The authors of this study review why previous studies have such wide-ranging results. They conclude that IDET is not beneficial for most patients with CLBP from disc disease.

Can a Shoe Insert Reduce Back Pain?

Even a mild difference in leg length from one leg to the other can lead to low back pain (LBP). Can a shoe insert make a difference? This is the question posed and answered in this study.

LBP patients with a 10 mm (about one-third of an inch) or less leg length difference were divided into two groups. The first group received a shoe insert made just for them. The insert was put inside the shoe of the shorter leg. Leg length difference was not corrected in the second (control) group.

Pain levels decreased in the group wearing the inserts. There was no change in the control group. The greater the difference in leg length, the more pain relief was obtained.

The authors point out that mildly shorter legs are rarely treated. Most people don’t realize it’s the cause of their back pain. Anyone with low back pain should be checked for leg length differences. Even one-quarter inch to one-third inch differences should be treated with a shoe insert for back pain relief.

Japanese Surgeons Report New Technique for Laminectomy

In a standard operation for lumbar canal stenosis (LCS) the muscles alongside the spine are cut and pulled away from the bone. This allows the surgeon better access to the spine to cut away some of the bone pressing on vital nerve tissue. In this study surgeons from Tokyo, Japan use a new technique that doesn’t involve cutting away the muscles.

The new method is called lumbar spinous process-splitting laminectomy (LSPSL). The backbone along the spine (spinous process) is split in half. The muscles and ligaments attached to the spinous process remain untouched. The surgeon separates the spinous process into two halves and pulls them out of the way. Then the laminectomy is performed. At the end the two parts of the bone are sewn back together.

The outcomes for two groups of patients were compared. Group one had the standard or conventional operation. Group two had the new LSPSL method. Measures used to compare results included muscle atrophy and recovery rate. Everyone was followed for at least two years.

The MRI results showed much better muscle definition and size in the LSPSL group. Atrophy was reported as 5.3 percent for the LSPSL group compared to 24 percent for the standard (control) group.

Surgical damage to the back muscles is a problem with laminectomy. The LSPSL method gives the surgeon a better view and more working space to gain access to the nerves. At the same time the LSPSL minimizes damage to the soft tissue supporting structures of the spine. Long-term results are needed before this method can be adopted.

Treatment for Lumbar Spinal Stenosis Still Debated

If you’re an older adult with lumbar spinal stenosis (LSS) (narrowing of the spinal canal), surgery may be an option. But if you can get pain and symptom relief without surgery, there’s less chance of other problems and complications. In this study researchers look at the result of conservative care for LSS. They try to find any factors that will predict outcome to help seniors make this treatment decision.

The study started out with 263 patients 70 years or older. Everyone was treated in the hospital. First they tried in-bed pelvic traction. If that didn’t work the patients got a body cast to put the spine in slight flexion, a position known to help with LSS. Corsets, injections, and nerve root blocks were also used if nothing worked so far.

In the end 140 patients had surgery because none of the conservative treatments worked. This study focused on the final 89 patients who got better and left the hospital without having surgery.

They found that patients most likely to do well with conservative care had the radicular type of LSS. This means there was pressure on the spinal nerve roots as they exited the spinal canal. The patients with the worst results had complete nerve block as shown with myelogram (dye injected into the spinal canal).

Poor Outcome with Dural Tears From Spinal Surgery

Tears of the dural sac called a durotomy are common during spinal surgery. The back half of the vertebrae form a protective circle around the spinal cord. There’s a covering around the spinal cord called the dural sac. This sac can get torn causing problems with headaches, low back pain, or leg pain.

In this study researchers report on the long-term results of durotomy in 41 patients compared to 41 normal (control) patients. They measured patients’ activity levels and ability to work. They also made note of anyone who needed more surgery.

The authors report a poorer outcome after durotomy when the tear isn’t repaired right away. Patients were unable to perform their usual activities. They were unable to work. Many had to change jobs or retire. Some had to have another operation.

Back Schools: How Much Does Your Back Really Learn?

Scientists haven’t been able to find one treatment program that works best for back pain. Every now and then researchers review recent studies looking for any evidence to support one treatment method over another.

In this study, researchers at the Department of Public and Occupational Health in The Netherlands studied the results of back schools. Nineteen studies were included.

Over 3,500 patients with low back pain (LBP) participated in a back school. They ranged in ages from 18 to 70 years old. No known cause was found for the LBP.

Are back schools more effective than other treatments (or no treatment at all) for LBP? The authors report most of the studies reviewed were poorly done. Data reported couldn’t be relied upon for a certain answer.

For now it looks like back schools given at the work site may reduce back pain and improve function more than other treatment. Other treatment such as exercise, manipulation, manual therapy, and advice don’t give as good of results.

The authors say better studies are needed before the effects of back school are truly known.

Looking Back: Results of Artificial Disc Replacement

Researchers at the Spine Center in Germany have teamed up with orthopedic surgeons at Yale University. The goal was to assess the safety and effectiveness of the Prodisc implant.

This implant is an artifical disc replacement. Such implants are slowly replacing spinal fusion for back pain. Motion is preserved. The vertebrae above and below the level of the implant don’t break down as they often do after spinal fusion.

All patients had the Prodisc implant at one-single lumbar level. Results were measured using patient satisfaction and pain levels. Use of medication and any complications were also included.

The results of this study show major improvement three months after the surgery. The good results were still present at the two-year check-up. The authors think the 96 percent satisfaction rate is a direct result of three things: 1) careful patient selection, 2) quality of the implant, and 3) experienced surgeon.

Back Pain in Nurses

Nurses and back pain are the subjects of this study. The authors followed 174 female nurses from the time they entered nursing school until five years into their nursing careers. Episodes of back pain were recorded and monitored.

Here’s what they found:

  • At least half the nursing students had back pain by the end of the
    first year in school; this was before the students had patient contact

  • Nurses who had back pain in school were more likely to have back pain
    during their nursing years

  • Back pain with leg pain (sciatica) was linked with lifting, twisting,
    and bent postures

  • Actual injuries only accounted for a small number of nurses’ back pain

    The authors conclude it may be possible to predict which nurses will develop back pain during their early years of nursing. It seems that pain and symptoms are already present and get triggered or made worse during school/work.

  • Retraining Workers After Back Injury

    A previous history of low back pain increases a worker’s chances of having another episode. How can we change this? Studying the forces through the spine during lifting might offer us some helpful clues when retraining a worker after the first injury.

    The object of this study was to show how spine loading compares between workers with and without low back pain. Everyone lifted four different weights in five positions. Electrical activity of 10 muscles was recorded. The muscles included trunk and abdominal muscles. A computer monitored the speed, direction, and force of trunk and back motions.

    Signals were collected using a special Microsoft Windows software developed by the Biodynamics Laboratory at the University of Ohio. The program made it possible for patients with low back pain (LBP) to lift without using maximum exertion. The researchers could still get the needed readings for the study.

    In this study they measured compression and shear forces when lifting in patients with LBP compared to subjects who’ve never had back pain. In some positions there was more than twice as much pressure through the spine for the back pain group. Shear forces were much higher for LBP patients when lifts weren’t in the center or midline. These lifts required combinations of movements like bending and twisting and are called asymmetric. The greatest differences in force between the two groups occurred when lower weights were lifted.

    The authors of this study have spent the last 20 years developing a three-dimensional model that show how much the spine is loaded during motion. Movements tested so far include forward bending, sidebending, and twisting. This study is a first step toward matching a patient’s ability to lift with the amount of load that goes through the spine during asymmetric lifting.

    New Information on Pain Pathways From Brain to Muscle

    Scientists are studying back pain to find ways to prevent it. In this study researchers measure signals from the brain to the back (erector spinae) muscles.

    Two groups were tested. Patients with low back pain were in the first group. Healthy, pain free adults were in the second (control) group. Transcranial magnetic stimulation (TMS) was applied to the brain. Electrical activity of the low back muscles was measured at L4.

    Activity of the left and right muscles was compared for patients and controls. The results showed that there is reduced activity along the pathway between the brain and the low back muscles.

    The authors aren’t sure what the results mean fully. With further study they hope to be able to use this information to help patients. Perhaps drugs can be found to alter the pain pathway from brain to muscles. It’s possible that motor training of the muscles might change pain patterns.

    Using Disc Space Height to Predict Outcome of Spinal Fusion

    Patients with back pain from a degenerative disc may be helped with surgery. The best treatment depends on the patient’s symptoms and findings during the doctor’s exam. In this study results of X-ray to measure the disc space are used to predict outcomes.

    Patients were divided into four groups based on disc space height (DSH) measured on X-ray. Disc height ranged from less than five millimeters (collapsed) to more than 15 mm (tall disc space).

    All patients had a single-level anterior spinal fusion. The procedure was called an anterior lumbar interbody fusion (ALIF). Everyone was followed for up to 24 months. Results were measured based on pain levels, physical function, and disability.

    Everyone in all four groups got better. The patients with the most collapsed disc space had the most improvement. They also had the earliest results with more pain relief and better function as early as three months after the surgery.

    The authors conclude measuring disc height before ALIF may help surgeons find patients who can be helped the most by this surgery.

    Physical Therapist Reports Back Pain From Cancer

    Physical therapists (PTs) report a case of low back, hip, and leg pain from cancer. In today’s health care system patients can see a PT without seeing a doctor first. This is called direct access. Therapists must know how to recognize signs and symptoms of illness or disease affecting the spine.

    The patient was a 45-year old man who had never been seen by a doctor or other health care provider for this problem. There were no medical records on file.

    There were some findings on exam to suggest a true back problem. However, the therapist was tipped off to a serious medical condition by the following:

  • Most intense pain at night
  • No known cause of pain
  • Unusual loss of left hip motion
  • Patient did not improve with physical therapy

    The PT advised the patient to see a medical doctor. Special tests showed lung cancer with metastases to the spine.

    The authors point out that cases like this are rare but show how PTs must know what to look for as signs of serious disease causing back pain.

  • First Study to Look at Muscle Strength in Patients with Disc Herniation

    We know that patients with low back pain (LBP) of unknown cause have weaker trunk and knee strength. Is this also true for patients who have lumbar disc herniation (LDH)? Does sciatica cause leg weakness on one side or in both legs? These are the questions asked by researchers in this study.

    Strength of trunk muscles and both knees was measured for LDH patients with and without sciatica. Results for all patients with LDH were compared to healthy volunteers (the control group).

    Researchers found much lower muscle strength in trunk and knee motion for the LDH patients. This was true with fast or slow movements. There was no difference in strength between the sciatica and non-sciatica legs in the LDH group. Both sides were weak.

    The authors say the weakness doesn’t seem to be coming from the effect of the LDH on muscles. Patients with nonspecific LBP have the same weakness. It may be that pain in the back and legs leads to physical disability and muscle atrophy.

    Weakness is the final result of both. Fear of pain may add to the problem. Patients stop moving normally when they’re afraid it’s going to hurt.

    This was the first study to look at the effect of LDH on both trunk and leg muscle strength. Future studies are needed to help explain the results. Scientists will attempt to find out what the exact mechanism is for decreased strength of trunk and both legs in patients with LDH. This information may help prevent such problems for LDH patients.

    Results of Minimally Invasive TLIF

    Spinal fusion works best if the vertebrae are supported with screws and a device called a cage. Surgeons are trying to find the best approach for the operation. There are problems operating from the front or back of the patient. In this study, researchers use a transforaminal approach.

    Transforaminal lumbar interbody fusion (TLIF) places the hardware from the side rather than from the front or back. In this study a small incision was made. This method makes the operation minimally invasive.

    The small opening was three to four centimeters to the side of the spinal column. The facet joint was removed. The cage and screws were inserted (one screw from each side). Special X-rays were used to guide the surgeon.

    Patients had relief from pain down the leg right after the operation. Back pain was reduced in most cases. The small incision reduced muscle injury and soft tissue damage. There was also less blood loss during the operation.

    The authors support the use of a minimally invasive TLIF over the more standard TLIF with a larger incision. Long-term results must be acceptable before adopting this method.

    Sacroiliac Joint Fusion: The Rest of the Story

    The sacroiliac (SI) joint can be a source of low back, buttock, or leg pain. In this article researchers from Johns Hopkins Medical School review the various causes of SI pain. Their goal is to see what kind of results patients have after fusion for SI joint disorders.

    There is only one test that can prove the SI is the source of the pain. The joint is injected with a numbing agent. More than 75 percent reduction of pain in 15 to 45 minutes is a positive test pointing to the SI.

    Fusion was done in 20 patients after pain relief was obtained from joint injections. Results of SI fusion were measured using general health, function, pain, and X-ray results.

    Results were good for all patients selected. The authors say SI disorders can be treated successfully with fusion. The key is to conduct joint injection tests. Fusion should only be done in patients who have failed other treatment and who have more than one positive joint injection test.

    Emotional Distress Negatively Affects Patients After Spinal Fusion

    Researchers often use a survey called the SF-36 to measure results of medical treatment. In this study the SF-36 is used for the first time in patients with chronic low back pain (LBP). Each one of the 57 patients had a single-level spinal fusion.

    The study was focused on finding out if the patients’ psychological or emotional status before surgery affected the results of their treatment. The survey measured physical and mental function. It also showed how the patients saw their own health.

    The authors report a real link between mental status before surgery and results after. Lower mental health scores were connected to poor overall outcomes. Likewise patients with higher mental health scores had greater physical function. Results were measured one and two years after surgery.

    The results of this study suggest a patient’s mental health before surgery can predict the outcome of spinal fusion. Surgeons might want to use the SF-36 with patients who have chronic disc-related LBP before spinal fusion surgery.

    People With Low Back Pain Have Global Pain Hypersensitivity

    Pain and tenderness are common features in patients with back problems. Physical therapists (PTs) press and feel patients’ skin and soft tissues to find out where the pain is located. This exam method is called palpation. In this study PTs measured the amount of pressure it takes to cause pain in patients with chronic low back pain (CLBP).

    The study was made up of two groups. One group had 30 women who had back pain for more than six months. The second (control) group were healthy volunteers (30 women) with no back pain. The goal was to see if the amount of pressure needed to cause pain is less in people with back pain compared to “normal” (healthy) adults.

    The researchers measured pressure pain detection threshold (PPDT) in 10 places on the body. Some test sites weren’t near the back. Other test sites were near the spine.

    They found all PPDT values (near and far from the spine) were lower for subjects with CLBP. The authors aren’t sure how to explain the difference. It could be based on how the nervous system works. Or there may be psychologic or emotional links.

    The bottom line for PTs is that palpation may not be an accurate test of pain. People with CLBP are more sensitive to pressure than other healthy pain free adults.

    Incidence, Risk Factors, and Results of Nerve Pain After Surgery

    Surgeons say numbness of the front and side of the thigh is common after spine surgery. The patient is placed face down over a special frame called the Relton-Hall frame. Pressure from the supports on a nerve close to the surface causes the problem. Just how often does this happen?

    In this study about one-fourth of the patients had impaired sensation after spine surgery using this type of frame. About half of those patients had numbness on both sides. The condition is called meralgia paresthetica (MP).

    Looking at all the data collected, these researchers concluded that there are three main risk factors for this problem. First, overweight and obese patients are at increased risk. While the patient is supported by the frame the large abdomen hangs down. This position with the suspended weight puts pressure on the nerve.

    Second, a longer surgery time is a risk factor. Surgery lasting 3.7 hours (instead of the usual 3.2 hours) increases the risk of MP. Finally, a third risk factor was diagnosis. Most cases of MP occurred in patients operated on for degenerative spine conditions.

    Although MP is common after some spine surgeries, the condition is temporary. The authors report everyone had returned to normal within two months. Many patients had complete recovery in the first week.