News Category: Lumbar Spine

Patients who need a spinal fusion often donate bone graft material from their own iliac (pelvic) crest. This is called an autograft. It takes quite a while for the fusion to occur. Often there are complications at the donor site.

To help with these problems, scientists have developed a special bone graft substitute called OP-1 (rhBMP-7). OP stands for osteogenic protein. Osteogenic means it stimulates bone growth. OP-1 comes in putty form and is now available for use in humans.

In this study, two groups of spinal fusion patients were compared. The first group had a fusion using an iliac crest bone autograft. The second group received the OP-1 putty. All fusions were done at a single spinal level following a decompressive laminectomy (removal of bone pressing on the nerve). The fusions were done without additional instrumentation (use of metal plates or screws).

Results were measured using dynamic X-rays of the moving spine. Fusion status can be assessed by looking at how much bone has developed to bridge the gap from the laminectomy. The X-ray also shows if there is any movement at the fusion site.

Patient function can also be measured using a variety of survey tools. The Oswestry Disability Index and the SF-36 questionnaire are two of the more commonly used tools to compare before and after results. Using these tools, success rates in this study were higher for the Putty patients.

The authors note that at least for the first two years after surgery, the OP-1 Putty provided an equally acceptable alternative to autografts for spinal fusion. There were good rates of fusion seen on X-rays. Patients reported overall improvement in function. There were some problems such as wound infection and pseudoarthrosis (false joint) in the putty group. There were no tumors, toxicity, or neurologic problems with the use of OP-1 putty.

Patients in this study will continue to be followed to assess the long-term results of OP-1 Putty as an alternative to bone autograft material. There is a concern that the putty might deteriorate over time. So far, there’s no sign of that happening in the medium- or intermediate-term outcomes.

The author of this article (Dr. T. Hoogland) has been involved for many years in performing lumbar discectomies (disc removal). The surgical technique has improved over the last two decades. Fifteen years ago, Dr. Hoogland developed new surgical tools to enhance the procedure. Special reamers are now available to make more room for an endoscope and other surgical instruments.

In this study, these special tools were used in patients with recurrent disc herniations. This is the first attempt to use transforaminal endoscopic discectomy for patients who needed another discectomy at the same level as the first operation.

The advantage of this technique is that it allows the surgeon to enter the spinal canal from the side and thereby avoid going through old scar tissue. By entering through the foramen (opening in the vertebral bone for the nerve root), the area could be widened at the same time.

This approach creates a working tunnel to the herniated disc. It also takes pressure off the nerve root and gives it more space. Local, rather than general, anesthesia was used (a second advantage). A third advantage is that less scar tissue is formed compared with dorsal techniques (going through the back of the vertebra to get to the disc material).

Decreased pain level, patient satisfaction, and rate of revision after a lumbar discectomy were the main outcome measures for this study. Early recurrence (within three months of the operation) was viewed as a postoperative complication.

Results were positive with a low complication rate and high patient satisfaction. Eighty-five per cent (85%) of the patients gave the surgery results a good to excellent rating. There was improvement in back and leg pain. Recurrence rate was less than five per cent.

Dr. Hoogland concludes that endoscopic transforaminal discectomy can be used effectively for repeat discectomies. There are many advantages to this technique over microdiscectomy. Being able to reach the protruding disc material without interference from scar tissue is an important breakthrough in surgical technique.

Pain beliefs are linked with pain intensity, psychologic distress, and disability. Having the wrong understanding or belief about the cause of your low back pain (LBP) can be more harmful than the problem causing the LBP.

In this study, researchers compare the pain beliefs of patients’ with two different types of LBP. The first group had noninflammatory LBP. This is the most common diagnosis in patients with chronic LBP. The second group had inflammatory LBP called spondylitis. Only 0.2 per cent of the western population has this type of LBP. The study also included a third (control) group of people who were pain free.

What patients believe about their pain dictate how they cope with their pain. For example, many patients with noninflammatory LBP believe that pain means there is ongoing damage occurring in the spine. They start to avoid certain activities or movements out of a mistaken belief that this will prevent further pain.

Another coping strategy is called catastrophizing. This is the belief that the pain will never go away. The patient is powerless to change and has no control over the situation.

Everyone in this study filled out four different surveys assessing their pain beliefs, coping strategies, and levels of catastrophizing. Analysis of the results showed that patients with noninflammatory LBP were more likely to be depressed and to catastrophize their symptoms.

The authors suggest that having a proper understanding of their diagnosis can help patients avoid unhelpful pain beliefs. Pain beliefs are learned and can be changed. Focusing on repair processes rather than damage or degeneration may be a good tool to use during treatment. The focus must be shifted away from thinking about LBP in a negative way.

Treatment of chronic LBP must take pain beliefs into consideration. Research results such as those provided from this study can help identify ways to change unhelpful beliefs in patients with chronic LBP.

In this article, two family medicine physicians offer a prescription for conducting a quick (10-minute) exam of the low back. The target population is adults with acute low back pain (LBP). This information is helpful since the majority of patients with LBP don’t have a clear cause of their painful symptoms. And most physicians don’t have the luxury of keeping hour-long appointments with their patients.

There are about a dozen key screening questions that can be used to identify the presence of a serious pathology. Quickly identifying infection, tumor, or fracture as the cause of the problem is important. If there are no red flags suggesting a significant problem, then a time-efficient exam can be completed in about 10 minutes.

The physician uses a four-part physical examination. This includes observing simple actions like moving and walking. Palpation of tender or painful areas and assessment of range of motion are next. The sciatic nerve can be tested for signs of compression, which might point to a disc problem. Muscle testing for gross strength helps identify nerve involvement.

If the LBP appears to be from a mechanical problem, then a treatment plan can be determined. Mild to moderately strong pain relievers may be needed to help break the pain-spasm cycle. The physician can prescribe Tylenol®, nonsteroidal antiinflammatory drugs (NSAIDs), muscle relaxants, or any combination of these.

Patients must be counseled and educated about resting, working, and driving. Anyone taking medications with a sedative effect should not be driving or operating heavy or potentially dangerous equipment. Resting in bed, inactivity, and taking time off from work is discouraged. The patient should remain as active as possible.

If no improvement is reported within three to five days, then the second part of the treatment plan takes effect. Referral to a physical therapist, chiropractor, or osteopathic physician is the next step.

Some patients seem to respond better to a combination of techniques. It may take a little time to sort this all out. The physician should plan a follow-up visit with the patient within three days to two weeks. Further testing may be needed for the patient who gets progressively worse rather than better.

Physical therapists (PTs) are involved in an ongoing effort to find out what works best to treat nonspecific low back pain (LBP). Nonspecific refers to the fact that no known cause can be found for the pain.

In this study, the results of two specific types of treatment for nonspecific LBP are compared. The first group received spinal mobilization. Mobilization is a technique used by PTs to improve movement at each individual vertebral level. The therapist applies pressure to the vertebra in a rhythmical and repetitive way. The authors describe the specific way in which spinal mobilization was applied to each patient.

The second group performed press-up exercises. These are done by the patient while lying face down on a table or mat. Using the arms, the upper body is pushed up away from the surface. The muscles of the back are kept relaxed, so that the arms do all the work. The abdomen and pelvis are allowed to sag back down onto the supporting surface. The authors also offered more details about the press-up technique used for this study.

Pain level was measured and dynamic MRI imaging of the lumbar spine was performed. Vertebral angles measured on the MRI gave a measurement of spinal motion at that level.
Both measures were taken before and right after a single-session using either mobilization or press-ups. The person collecting this information did not know which treatment group each patient had been in.

Pain was less for patients in both groups after one treatment. Lumbar extension (backward motion of the low spine) was improved in both groups. There was a slightly greater amount of motion improvement in the mobilization group. However, one treatment was not more effective than the other in achieving overall pain relief or increasing motion.

The authors point out some limitations of their study that should be considered. First, the small change in lumbar motion may have been linked to the patient’s age or activity level. All the patients in this study were young and active.

Second, the results of this study are short-term (after one session). Long-term results still need to be investigated. Some changes in pain and motion could have occurred from the testing procedures themselves. More studies are needed to evaluate these two treatment techniques for nonspecific LBP.

Patients who herniate a disc at the L5-S1 lesion face surgery that can be difficult because of the location of the disc and its difficult access. While posterior approaches have been done regularly, an anterior approach, transabdominal is proving to be a viable technique. The authors of this article review the surgical method and evaluate its effectiveness and safety.

Researchers located 30 patients who had undergone transabdominal percutaneous lumbar discectomy (TPLD) for treatment of L5-S1 extruded disc fragments. The patients were, on average, 42 years old. Five patients had undergone surgery previously. All patients had undergone conservative medical treatment but had not been relieved of their pain.

To undergo the procedure, several steps had to be followed. Step 1 involved bowel preparation, which is crucial to obtaining optimal outcome of the surgery. Following the bowel protocol, which evacuated the bowels, the patients received a barium meal that would help the surgeon visualize the bowel. The patients also received metoclopramide to enhance bowel tension, and barium was introduced through the rectum to fill the left colon.

The patients underwent spinal anesthesia as their assistance is needed for this surgery. The discectomy is performed and broad-spectrum antibiotics are injected into the disc space to prevent infection. Evaluation of success begins immediately after surgery with straight leg raises and neurological examination.

After the surgery, the patients were followed for between 12 and 30 months. Their progress was assessed regarding function and pain. Patients filled out a standard spine questionnaire and every three months, x-rays, computed tomography (CT) scans, or magnetic resonance imaging (MRI) were performed. In the case where patients couldn’t be evaluated by the researchers, they were interviewed over the phone regarding their progress or any problems.

The results showed that the TPLD was technically successful and well-tolerated in all patients. Only one patient did not see a resolution of pain or neurological problems and one patient developed pancreatitis. Before surgery, the mean visual analog scale (VAS), measuring the intensity of pain from 0 to 10, with 10 being the most severe, was 7.1. After surgery at the final follow-up, VAS was 0.933. The McNab classification of excellent, no pain, no restriction of activity; good, occasional back or leg pain of sufficient severity to curtail or modify work or leisure activities; fair, improved functional capacity but handicapped by intermittent pain of sufficient severity to curtail or modify work or leisure activities; or poor, no improvement or insufficient improvement to enable an increase in activities and thus further operative intervention required, was used to measure progress. According to the Mcnab criteria, all patients showed good results (26 were excellent and four were good).

The authors wrote that the advantages of this procedure over the traditional approach from the back included avoiding paraspinal muscle trauma and partial denervation, the ability to remove more of the offending disc, which minimizes the possibility of recurrent herniations at that level, less pain after surgery, and earlier discharge from the hospital. They point out that the preoperative measures must be strictly enforced in order to minimize the potential of complications and the surgical procedure must follow exactly as is indicated.

There were some limitations to the study, the authors pointed out. This included that this was not a comparative study and there was no control group. They conclude, however, that TPLD is a safe and effective method of treatment for removing lumbar disc herniations at the L5-S1 level.

In this article, the authors report the case of an 81-year-old woman who was diagnosed with a primary hydatid cyst on the thigh. This cyst caused radiating pain down through the left sciatic nerve, as well as numbness and weakness in the left foot and leg.

The patient had initially been treated conservatively with no relief. Following assessment with magnetic resonance imaging (MRI), some disc herniation at L4-5 was detected but with no nerve root compression. Six months later, the patient was seen to have a slowly growing mass on the left thigh.

AFter further testing, a cyst was seen and surgery was performed on the patient. The surgeons discovered a lesion tangled in the sciatic nerve, which they were successful in removing. After the surgery, the patient was given antiparasitic medication and a medication to prevent muscle spasms. Within a few days of the surgery, the pain from sciatica was significantly improved.

While hydatid cysts are not unusual, they are rarely found in the soft tissues. In certain areas of the world, human hydatidosis is still a public health issue that can lead to neurological problems. The authors of this article suggest that physicians must be aware of the possibility of such a cyst, which can be accurately diagnosed using ultrasounds, computed tomography scans (CT scans), or MRIs.

If suspected lesions are found through testing, blood work for serology can confirm the cysts’ presence.

Before the cyst can be removed, it’s essential that the patient be tested for hydatidosis, a tissue infection of the parasite. If there is such an infection, if it is exposed during surgery, the patient is at increased risk of anaphylaxis. This diagnosis, however, isn’t easy. Biopsies are not recommended because of the anaphylaxis risk and the risk of contaminating nearby tissues. Acknowledging this difficulty, the authors of this study chose to remove the mass while contained in the muscle tissue, rather than just removing the cyst alone.

There are reports in the literature of physicians who used chemotherapy and percutaneous treatments to shrink the cysts and avoiding the need for surgery. The medication albendazole has been effective.

The authors conclude that physicians should consider the hydatid cyst as a possible diagnosis, particularly if the patient is from an area where the possibility is high.

Phantom pain and/or stump pain are experienced by approximately 80 percent of people who have undergone amputations. Phantom pain, the feeling of pain in a limb that is no longer there, isn’t completely understood. Often described as burning, aching, or cramping, phantom pain does seem to improve eventually for many. Stump pain, on the other hand, appears to originate from the nerves at the amputation site and has been described as pressing, throbbing, burning, or squeezing.

The authors of this article describe the case of a 41-year-old man who had complained of severe stump pain two years after undergoing a left leg amputation following a motor vehicle accident. At this point, the stump pain had been unrelenting for the previous 15 days and the patient rated it at 100 on a scale of 0 to 100, with 100 being the most severe ever.

After examining the patient for anything that could be causing the stump pain, such as infection, tissue breakdown, wounds, or edema (swelling from fluid), the doctors were unable to pinpoint the cause of the pain.

In the orthopedic department, the doctors x-rayed the stump without discovering any indication of the cause. They injected the stump with a local anesthetic without any relief reported by the patient. At this point, the doctors performed a lumbar magnetic resonance imaging scan (MRI) when they located that a disc had herniated at the L4-5 level.

Following surgery for the disc herniation, the patient was pain free (reporting zero out of 100) and was able to wear his prosthesis.

The authors conclude that although this cause of stump pain is rare, it is a possibility and should be kept in mind when diagnosing stump pain.

Back pain from a degenerative or protruding disc can be severe and disabling. So severe that surgery to remove the disc is needed. This procedure is called a discectomy. In this study, surgeons compare ways to reduce pain after the surgery.

Two groups of patients were included. All patients had a one-level lumbar microdiscectomy. Microdiscectomy refers to the use of a minimally invasive approach. A very small incision is made. Special surgical tools are used that allow the surgeon to see inside the spine without making a large incision.

This was the first time any of these patients had back surgery. They all had a piece of underskin (fat) harvested from their own bodies. It was then used as a patch over the epidural area. This helps prevent spinal fluid from leaking.

One group received a graft with meperidine injected into the graft before it was put over the epidural site. The other group just had the graft placed without the meperidine. Meperidine (also known as Demerol) is a fast-acting opioid analgesic (pain reliever).

All patients were given a patient-controlled analgesic (PCA) pump to use for the first 24 hours after surgery. The PCA released a small dose (20 mg) of Tramadol (a weak opioid analgesic). They were allowed to control their own drug use with at least a 10-minute interval between doses.

Results were measured based on pain severity and the amount of drug used during the first 24 hours. The authors report the group with the meperidine graft had much less pain the first hour after the operation. Total amount of pain relieving drug used was also lower in the meperidine graft group.

The authors encourage surgeons to reduce patient postoperative pain whenever possible. This can be done by minimizing trauma during the procedure. Minimally invasive techniques can be used. Tissues must be handled skillfully and carefully.

The use of a meperidine graft can also reduce pain. Proper pain control makes it possible for the patient to get up and move about sooner. Early mobilization can reduce the risk of blood clots after surgery. Patient-controlled analgesia is expensive and isn’t always available. In such cases, the meperidine seeps into the epidural cavity during the first 24-hours. This effect can also reduce pain and sensation.

Evidence-based medicine is a major focus of research right now. Without evidence that a specific treatment is effective, methods that don’t really work can be eliminated. Studying different treatments for low back pain is one way to find out what works best.

Randomized controlled trials (RCTs) are considered to be a model approach to quality research. Patients are divided randomly but equally between treatment groups. Whenever possible, the patients and/or the clinicians have limited (or no) knowledge of who is being treated and by what method.

In this systematic review, RCTs of acupuncture versus manipulation of the spine were examined and compared. Articles were included from around the world and in any language.

Each study was examined to see if it was an expertise-based RCT. This means that each participant was randomized but only clinicians with expertise in the area of intervention saw the patient.

In conventional RCTs, patients in group A (acupuncture) or B (manipulation) were treated by clinicians who may not have expert skills in the assigned area. In other words, one practitioner provided both competing therapies. In the area of acupuncture, this may have been an anesthesiologist with training in acupuncture or a chiropractor with experience in acupuncture.

Bias in results can be reduced. This is done by having all patients assigned to the acupuncture group receive acupuncture from the most expert acupuncturist available. Likewise, manipulative treatment should only be delivered by someone highly skilled in this modality.

It’s possible that someone providing both types of treatment but with greater expertise in one area over another will bias the treatment toward the area of their particular expertise. Having clinicians who only provide the therapy for which they are an expert would increase the validity of RCTs and make them evidence-based.

The authors evaluated the role of tumor necrosis factor a, TNFa, in patients with low back pain. Inflammatory cytokines such as TNFa are known to play a role in central and peripheral pain perception. The authors chose to evaluate the presence and level of TNFa in subjects with chronic low back pain. Upon entry to the study, 56 percent of the subjects with chronic low back pain versus 12 percent of the healthy control group were positive for TNFa. The TNFa level was evaluated four times over the course of six months.

While the levels decreased in those with chronic low back pain after participating in a multidisciplinary treatment initially, they remained higher than the control group over the six month period. Even when pain and function improved in the chronic low back pain group, the TNFa level did not significantly decrease as might be expected. Therefore, the authors do not feel that the presence or level of TNFa is useful as a predictor of the clinical course in patients with low back pain. The clinical relevance of the findings are uncertain. They do feel that treatment targeting TNFa may be worth further exploration.

Waddell et al defined illness behavior that can be relevant to both the development and the maintenance of chronic pain. They developed a screening tool to screen for nonorganic signs that they feel indicate emotional or psychological distress. This can be beneficial in terms of further assessment and treatment. The Waddell score consists of eight standardized physical nonorganic maneuvers, divided into five categories. The overall score is positive if at least three of the categories are scored positively.

Some clinicians have criticized these signs even though there is increasing evidence that these nonorganic signs are associated with poorer outcomes and greater disability. The authors of this study agree with others that there is limited literature, and conflicting outcomes regarding the reliability of nonorganic signs.

The authors recruited 126 subjects with chronic low back pain. Two examiners were involved in testing the subjects for nonorganic signs two times over the course of the study. The prevalence of positive signs and categories varied from 14 percent to 49 percent, and was 36 percent for the Waddell score.

The authors concluded that the Waddell score when used by the trained observers in their study demonstrated moderate interobserver reliability. The intraobserver reliability was good.

Spondylolisthesis is a condition that usually affects the lumbar spine. It occurs when one of the vertebrae slips forward over the one below it. As the bone slips forward, the nearby tissues and nerves may be pulled or pinched causing nerve irritation and pain.

Over the past 20 years, the treatment of spondylolisthesis has evolved. Fusion remains the gold standard in the management of moderate to severe spondylolisthesis. Newer methods and technologies such as bone substitutes for the graft site and stabilization devices are being studied.

In this review article, the pathophysiology, evaluation, and natural history of degenerative spondylolisthesis are presented. This type of spondylolisthesis occurs in adults age 50 and older.

The disc starts to thin out and the disc space gets smaller. As the disc and vertebra start to collapse, pressure increases on the adjoining facet (spine) joints. Arthritic changes at the joint and buckling of the ligament along the length of the spine add to the progress of this condition.

Women are affected most often. Scientists think this may be because of greater joint laxity and influence of estrogen in women. For about one-third of the patients with spondylolisthesis, the condition rarely gets worse. Back pain may even get better as the spine stabilizes itself.

Three-fourths of the patients without neurologic signs remain stable and don’t need surgery. But for the patients with buttock pain and/or numbness down the legs, surgery may be the best option. Conservative care is always advised first. This may include antiinflammatory drugs, activity modification, and physical therapy.

When surgery is recommended, the procedures available include decompression with fusion and fusion with or without instrumentation. Decompression involves removing a piece of bone to take pressure off the spinal cord or spinal nerve root. Instrumentation refers to the use of metal plates, screws, or wires to hold the spine in place.

The authors review results of each of these operations based on studies published in the last 20 years. More recently, fusion with transforaminal lumbar interbody graft and fusion with biologics are being used. The interbody fusion increases the fusion surface area creating a more stable segment. Biologics refers to growth factors that are able to increase bone growth.

Currently under investigation is the use of motion sparing technology. These devices are inserted between the spinous processes of the vertebrae to distract (separate) the bones and stop motion. The spinous process is the bump you feel along the back of your spine. By preventing spinal extension, the nerves are protected from further pinching or pressure.

More and more older adults with chronic lumbar pain are having spinal fusion to treat the problem. As a result, surgeons face new problems to deal with. For example, once a moving spinal segment is fused, the load on the other (adjacent) segments increases. The result may be adjacent segment degeneration (ASD).

But it’s not clear yet if these changes cause clinical problems. The changes can be seen on X-rays. The question is: do they cause painful symptoms or loss of function? In this study, patients treated with L4-L5 or L5-S1 fusion are observed for many years after the surgery. Periodic X-rays and clinical exam were performed.

Their pain levels, function, and satisfaction are measured and tracked over the years. Disc space height, movement of the vertebrae, and angle of the lumbar spine alignment were also calculated or assessed.

Follow-up results showed that patients with a L5-S1 fusion had fewer cases of ASD. Fusion at the L4-L5 level seemed to result in a greater risk of ASD. If the fusion was done at the level of the stable sacral base, then there was a trend toward fewer cases of ASD. Fusions at the L4-L5 level called floating fusions were more likely to develop ASD.

The rate of ASD did not seem to depend on the way the surgery was performed. There were two different methods for fusing the lumbar spine used in this study. A detailed description of approach, operative strategy, and postoperative program used for these patients was included for the readers.

Important factors affecting the outcome of the procedure included the angle of the sacrum and the age of the patient. Younger patients (less than 45 years old) were less likely to develop ASD. A more vertical angle of the sacrum was accompanied by higher rates of ASD. The type of surgery performed did not seem to make a difference.

The results of this study confirm what other studies have shown. Stress and shear forces increase on adjacent spinal segments after spinal fusion. The level above the fusion is subjected to the most changes.

Newer procedures using cage devices in between the vertebrae to correct the sacral angle may have better results. But even with these implants, there is concern about early degenerative changes seen on X-rays at the adjacent segments.

However, it’s not clear if changes observed on X-rays translate to increased painful symptoms and loss of function clinically. Re-operation isn’t necessarily the next step when ASD occurs. More studies are needed to identify predictive factors for successful outcome of fusion. This could help predict which patients are good candidates for lumbar spinal fusion with lower risk of ASD.

In this study, 39 patients over the age of 65 were treated surgically for severe lumbar stenosis. Spinal stenosis describes a clinical syndrome of buttock or leg pain with or without back pain. The opening for the spinal cord and spinal nerves narrows with age. Pressure on the nerve tissue can cause this pain, and in some cases, numbness, tingling, and weakness.

With older adults living longer, in better health, and more active, effective treatment for this problem is needed. Decompressive surgery to remove the bone from around the nerve tissue is often needed. The spine is then stabilized with a fusion. Results of this type of fusion was the focus of this study.

Titanium rods and screws were used for the fusion. This type of allow is less stiff and allows some give. A less rigid rod is needed when the bone is osteoporotic (brittle). Poor bone density makes it difficult to attach fixation hardware. Stiffless rods are a good solution for this problem.

X-rays and bone density tests were done on each patient before and after the operation. About one-fourth of the group had a one-level fusion. Half the group had two levels fused. The rest were three or four-level fusions. Everyone was followed for at least two years.

There were no major problems reported after fusion for the entire group. No reoperation or adjustment to the hardware was needed. Fusion was complete in 35 of the 39 patients. Broken rods and screws occurred in a few cases but did not cause any symptoms. The spines remained stable in those cases.

The authors concluded that less rigid fixation can be used successfully when the patient has poor bone quality. This means that patients with severe lumbar spinal stenosis who also have osteoporosis can be treated surgically.

The use of small diameter Titanium rods with large thread is advised. This eliminates the need for reinforced anchoring to the bone. Complete correction of spinal deformity caused by vertebral rotation or slippage is not needed. Further study using this less rigid fixation is still needed.

Total disc replacement (TDR) was approved by the FDA in 2004. Since that time, more surgical centers have started to include this procedure. But how often does the average community-based spinal surgeon have patients who could benefit from this operation?

In this study, the charts of patients seen for lumbar surgery by one private practice surgeon were reviewed. Fusion and nonfusion patients over a period of 15 months were included. The goal was to identify how often patients in a typical spine surgery practice might be a good candidate for TDR.

As it turned out, there were 190 patients who had lumbar spine surgery during that time period. Two-thirds had nonfusion procedures. The remaining one-third had a spinal fusion. The authors used criteria from two well-known studies to determine eligibility for TDR.

None of the patients in the nonfusion group were good candidates for TDR. Everyone had at least one factor that was considered a contraindication (reason not to have the surgery). About 14 per cent of the fusion group would have been potential candidates for TDR surgery. Only half of those patients eligible had private health insurance.

Only five per cent of the entire group (fusion and nonfusion patients) were potential candidates for TDR. The authors point out that this figure is much less than the 70 per cent previously predicted by the companies that manufacture the TDR implants.

These results were consistent with information from other studies. However, not everyone uses the same indications and contraindications when evaluating patients for a TDR. It’s likely that as TDR technology improves, more people will qualify for TDR surgery. For now, it appears that patients who qualify for spinal fusion groups are also the most likely candidates for TDR.

Scientists are studying new materials to replace bone graft for use in spinal fusion surgery. In this study, Chitra-HABg, a glass ceramic composite was used on one side of the spine. Natural bone graft harvested from the patient’s own pelvic bone. This is called an autologous bone graft. The harvested bone was placed on the other side of the spine.

Patients were followed for a full year. But it quickly became apparent that the ceramic graft substitute was being absorbed by the body without bone to replace it. Fusion failed on the ceramic side of the spine. As a result, the study was ended early.

Biodegradable, bioactive ceramic substitutes such as Chitra-HABg combine the best mechanical and biologic properties of various ceramics available. But it can’t be used alone as a bone graft substitute.

Researchers will continue to explore ways to avoid using autologous bone grafts. The complications at the donor site are often the biggest problem patients have after spinal fusion.

Bone substitutes must be porous in weight and structure like the surrounding bone. New bone grows into the interconnecting pores in the bone. A microlock forms between new and old bone. Autologous bone takes three months to a year to form a solid fusion. Bone graft substitutes or graft extenders must provide equally rapid growth of new bone.

Glass ceramic seems like a good choice for a bone substitute material. It is strong and provides a chemical surface that allows for new bone cells to stick. But it appears that new bone doesn’t go deep enough into the ceramic. It may be a problem with in-growth but it could be that the ceramic is too thick.

Other factors in the failure of fusion to occur with Chitra-HABg include poor local bone growth, too large of a soft tissue gap to fill in, and too small of a bone surface area for fusion to occur within. Despite more than three years of clinical trials, the makers of this ceramic bone substitute are back to the drawing board.

Scientists are looking for good ways to surgically treat acute lumbar fractures. Balloon kyphoplasty has been used by some, but there are a few problems with this procedure.

During kyphoplasty, a long, thin needle is inserted through the skin and soft tissues into the fractured vertebral body. A deflated balloon is pushed through the needle and placed inside the collapsed bone. The balloon is inflated in order to restore the vertebral height.

The balloon is deflated and removed. Once the balloon is removed, then cement is injected through the needle into the open space. Patients experience rapid pain relief and return of function after kyphoplasty.

But without proper support along the front of the vertebrae, the results may not last. Loss of correction has been reported. In this study, surgeons from Greece used balloon kyphoplasty along with pedicle screw fixation to fuse the segment. The use of hardware to fuse the spine is referred to as instrumentation. Patients included all had a lumbar compression fracture. They were operated on within two days after the fracture.

Screws were placed through the pedicles (upright columns of supporting bone) at the level of the fracture and above and below the fractured bone. Biocompatible self-hardening calcium phosphate cements were used. This type of cement doesn’t increase the heat inside the bone and can stimulate the growth of new bone.

Results of fusion were assessed using X-rays and CT scans. Pain levels before and after the procedure were also recorded. Pain improved after surgery up to six months after the procedure was done. No further improvement in pain was reported after six months. Physical function improved during this same time frame.

The formation of bone bridging was seen on X-ray as early as three months after surgery. No further bone development was seen after eight months. Solid fusion was seen eight to 10 months after surgery. There was increased stiffness at the level of the segmental fixation.

Although the results of this study support the use of balloon kyphoplasty with instrumentation, long-term results must be studied. Loss of correction and increased deformity might occur later (after 10 months). Short-term results support the use of this technique to treat burst and compression lumbar fractures.

Spondylolysis is a fracture of the pars interarticularis in the lumbar spine. The pars articularis is also known as the pedicle. It’s the area of bone between the upper and lower facet (spine) joints.

Motion at the site of the fracture can create a pseudoarthrosis or false joint. Low back pain is common with this condition. But the exact cause of the pain remains a mystery. Some experts suggest the extra motion at the wrong place causes the pain. Others believe the fibrocartilage that fills in the defect has nerve endings.

Japanese scientists studied the spondylitic tissue removed from 17 patients. All patients were adults with low back and/or leg pain from spondylolysis. Tissue samples were prepared, stained, and studied under a light microscope.

X-rays of flexion-extension motion were also taken and studied. Severity of low back pain was recorded. Both of these measures were compared to the tissue samples taken.

They found the spondylolytic tissue was made of the same type of tissue found in tendons and ligaments. It was dense, fibrous tissue made up of collagen fibers. There were no nerve endings or nerve tissue. There were some elastic fibers present. These were part of the normal ligament along the spine and not really part of the spondylolytic defect.

The authors were unable to find the cause of pain associated with spondylolysis. The healing spondylolytic tissue was not linked with low back pain. Neither was the loose lamina (tissue next to the pedicles). The ligament-like tissues that form to stabilize the fractured pedicles may be the cause of the pain, but more study is needed to find the exact link.

Lumbar spinal stenosis (LSS) is a common condition among older adults. The US Agency for Healthcare Research and Quality (AHRQ) estimates that up to 14 per cent of adults with low back pain have severe enough LSS to need surgery.

Many others in this age group suffer from painful symptoms who never see a doctor or who don’t want surgery. Finding the best treatment for this condition is the goal of the Spinal Stenosis Work Group of the North American Spine Society (NASS).

This review article is an attempt to provide a summary of the best evidence-based clinical guidelines for the treatment of chronic LSS. These guidelines will help physicians and patients decide the best approach for the patient.

The committee followed 12 specific steps in reviewing the literature on LSS and assessing levels of evidence before making recommendations. Each of these steps was described in this report. When evidence wasn’t available, expert opinion was included. Guidelines were not adopted unless there was agreement among the group members.

Eighteen questions were posed during the review of studies published before April 2006. Each of these questions was presented and the findings summarized. Some of the questions included: