Degenerative disc disease (DDD) is very common and is not always related to pain. However, if a patient is experiencing back pain, it is more likely the patient does have DDD or is in the process of acquiring it. Our models help explain that DDD is often a process and often intertwined with aging and spinal pain conditions.

Degenerative disc disease (DDD) is at the roots of Dynamic Disc Designs (ddd). Learning and teaching the underlying mechanisms of pain and the strategies to relieve and live with this common condition is what we strive to do. Bringing the research to the forefront, in front of the patient and doctor with a dynamic teaching tool.

lumbar creep

A study of male and female humans  1 subjected to three bouts of lumbar flexion-extension prior to, and after 10 minutes of static lumbar flexion confirmed prior animal studies that concluded static flexion caused lumbar creep in nearby viscoelastic tissues and alterations and spasms of the associated muscle functions. Researchers proposed micro-damage in the viscoelastic tissues occurred as the muscles attempted to compensate the relative loss of tension, creating spasms in more than half of the subjects while maintaining static flexion poses.

What’s at Stake?

Workers who must endure long periods of static lumbar flexion suffer high rates of lower back pain and degeneration, making static lumbar flexion a common risk factor for developing lower back pain and degeneration. How this occurs is not well understood. Recent studies have used feline models to better understand the processes involved in how static lumbar flexion creates creep and electromyographic spasms of the multifidi in the lumbar viscoelastic tissues under loads. In these studies, the multifidus muscles developed hyperexcitability during the post-static lumbar flexion resting period, particularly between the 6th and 7th hours of rest, and a full muscular hyperexcitability and creep recovery could take as long as 48 hours, which suggests that a transient neuromuscular disorder occurs after 20 minutes of static lumbar flexion. This new study was conducted to determine if healthy humans would experience the same transient disorder after static lumbar flexion.

flexion and pain

The Study

Study subjects included 24 males and 25 females with an average age of 23.7 years and no history of spinal function disorders. An additional six subjects were included in a control group. Electrodes were applied at the L3-4 level of the erector spinae musculature. Two-dimensional video motion analysis was performed to determine joint angles, and the data was collected prior to calculating lumbar flexion and overall flexion levels.

The subjects were instructed to stand quietly for three seconds then perform a full anterior flexion position over 2-3 seconds and hold the position for 3-4 seconds. The subjects then extended into an upright position over the course of 2-3 seconds and stand in a static position until the end of the recording. The recordings were 16 seconds long, with approximately 12 seconds of trial consideration. The subjects performed the deep flexion trials three times, with a 3—50 second break in between each trial.

Following the first trial sets, each subject was placed in a full lumbar flexion position on a physical therapy mat, with a foam bolster placed beneath their hips to ensure their pelvis was posteriorly placed and their knees were able to flex. This positioning reduced hamstring stretching and focused any tension (or creep) towards the posterior of the lumbar spine. They were asked to hold this position for 10 minutes while an EMG recording monitored any spasms or muscle activity. After this deep flexion period, the subjects were asked to stand up and perform three more flexion trials. The variables and data from all the trials were then extracted and analyzed.

Results

The results of the trial study indicated that there were clinically relevant changes in the flexion-relaxation response after 10 minutes of deep static lumbar flexion. The erector spinae muscles remained active longer and became active earlier prior to anterior flexion and during extension. This was due to moderate creep in the viscoelastic structures of the spine. The muscle activity intensity remained the same after static flexion, and there appeared to be variation in the flexion-relaxation response between the male and female subjects. Static flexion stances appeared quite often to cause visible EMG spasms.

When the subjects initiated anterior flexion, the muscles in their erector spinae slowly increased contraction to counter the increasing gravity effect on the upper trunk and head. Eventually, the passive forces of the strained viscoelastic structures were able to offset the upper body and head mass gravity, making the muscular forces unnecessary and causing them to disperse. The increase in flexion required the subjects to contract their abdominal muscles to counter the posterior viscoelastic tissue forces.

Conclusion

In this study, static lumbar flexion developed lumbar creep in the viscoelastic structures of the subjects. However, this effect was countered by the subjects’ musculature, which initiated or maintained the necessary active force during the periods of decreased viscoelastic tissue capacity. The results of the study confirm a synergy between the neurological system and the body’s ligaments and muscles that helps preserve skeletal stability and control movement. Further, microdamage to the collagen structure that may create spasms in the muscles appear to be related to viscoelastic tissue creep.

 

 

biomedical cause, LBP

An Australian study 1 into what male and female lower back pain (LBP) patients believe about the cause of their LBP flair-ups found that the subjects were most likely to attribute the source of their recent pain to biomedical causes, including active movements and static postures, rather than psycho-social factors. Though current evidence points to a positive correlation between mental health issues, including stress, anxiety, and depression, and LBP, few of the patients in this study attributed the onset of LBP flair-ups to psycho-social causes.

What’s at Stake?

LBP is the most common global cause of disability, lost income, and productivity decreases in the marketplace. Post-acute LBP flair-ups contribute to chronic job absenteeism and economic disruption at the individual and collective societal levels. While many studies have investigated the various causes of acute LBP episodes, few have focused on the fluctuations and triggers of LBP flair-ups.

Initial episodes of LBP are considered by health professionals to be overwhelmingly biomedical/biomechanical in origin, and most patients when queried agree with that assumption.

This study was conducted to determine what LBP patients believe about the triggers of their LBP flair-ups, in the hope that better understanding patient views will lead to more effective management of intermittent, non-acute episodes of LBP.

 

Professional LxH Dynamic Disc Model

Professional LxH Dynamic Disc Model

The Study

One hundred and thirty male and female volunteer subjects with episodic LBP participated in the online study by answering questions about their beliefs about the triggers for their flair-ups. Their answers were analyzed for common factors and were then clustered into various themes and codes by similarities. These common codes were further categorized into two overarching themes—biomedical, and non-biomedical triggers.

Overarching Theme: Biomedical Triggers

More than eighty-four percent of the subjects identified their LBP flair-up triggers as biomedical. Active movement and static postures were the most commonly identified biomedical causes for this group’s LBP recurrences. Patients reporting active movement as a trigger for their recurring LBP were most likely to cite bending and twisting as the most frequent instigator of their pain. Many of these patients felt that the quality of these movements played a role in initiating their LBP. In these cases, it was not the movement itself, but the way they performed the movement that caused their pain.

Roughly 5 percent of the patients reporting active movement as the cause of their LBP flair-ups believed it was repetition of the movement that was responsible for their pain. They claimed that “overdoing” a task could lead to LBP episodes.

Some of the patients reporting biomedical triggers believed their LBP was caused by biomechanical dysfunction. Roughly two percent reported motor control issues, and another 2.3 percent blamed their pain on spinal damage of some kind. Other biomedical themes included knee pain, endometriosis, and constipation. Some patients felt their LBP flair-ups were caused by lack of exercise, and others blamed work for their pain. Two percent reported their flair-ups were caused by not taking maintenance pain medications as prescribed.

Other biomechanical causes included participation in sex, wearing the wrong shoes, and medical treatments.

Overarching Theme 2: Non-biomedical Triggers

Only 15.2 percent of the subjects questioned reported non-biomedical triggers as the source of their LBP. Two participants—one male, and one female—believed the cause of their flair-ups to be related to stress or the weather. A few reported psychological factors—including anxiety, the lack of creative outlets, family problems, and depression— as potential triggers of pain.

The patients who claimed the weather was a factor in their pain were most likely to blame a drop in barometric pressure or the cold. One patient believed the pain episodes were triggered by rain, temperature changes, or warm weather.

Two percent of patients who attributed their discomfort to non-biomedical conditions blamed irregular or bad sleep qualities for their pain. Roughly 1 percent felt their diet had something to do with their LBP flair-ups, and another 1 percent blamed fatigue.

Conclusion

More than half of the patients with intermittent LBP flair-ups believed their pain was caused by biomedical dysfunctions, and only a few believed the source of their pain was something other than biomedical problems. Active movements and static postures were the most cited triggers for LBP.

The findings in this study are consistent with previous literature about what patients believe to be the cause of their LBP. However, the lack of patient emphasis on psychosocial causes of LBP contrast with current evidence that indicates a positive correlation between psychological or mental states and persistent LBP.

The authors of this study emphasize the importance of further research into the validity of the triggers identified by the LBP patients in order to better understand LBP flair-ups and how those experiencing them conceptualize the event. Evidence indicates the efficacy of patient-centric treatment in LBP clinical outcomes, and better understanding what patients believe about their pain will help clinicians to identify more effective treatment plans to manage recurring LBP in their patients.

facet, lumbar spinal stenosis model

A retrospective CT scan and medical record review [ 1. The Prevalence of Asymptomatic Cervical and Lumbar Facet Arthropathy: A Computed Tomography Study] of 50 patients with no history of spinal pathology used a four-point scale to grade the severity of evident arthritis and found that arthritic spinal changes were frequently evident—even in asymptomatic patients. The incidence of these changes corresponded positively with aging and was more prevalent in scans of the lower lumbar spine.

What’s at Stake?

Chronic neck and lower back pain affect between 66 and 84 percent of the U.S. population and is responsible for approximately 87 billion dollars of lost income and medical expenses annually—a figure that is only surpassed by the yearly wage loss and expenditures on diabetes and heart disease.

Diagnosing CNP and LBP is problematic due to the number of possible factors—including dysfunction of the intervertebral discs (IVD’s), facet joints, spinal nerve roots, ligaments, and muscles surrounding the spine— that can contribute to these disorders.

Some studies have indicated that facet arthropathy, rather than nerve root irritation, cause axial neck and back pain. The increase of CNP and chronic LBP in aging populations may be associated with a progressive degeneration of the IVDs that subsequently increases facet joint loading and creates favorable conditions for the development of facet arthritis. Facet joint blocks by injection have been shown to be ineffective in providing symptomatic relief in up to 90 percent of patients diagnosed via CT scan in previous studies. This suggests that scan observations alone may provide prevalent false positive results and therefore cannot be a reliable diagnostic tool.

Disc replacement may alleviate pain and restore spinal fluidity of motion, but the presence of facet joint arthritis is considered a contraindication to this surgical procedure. Understanding more about facet joint arthritis can assist practitioners in developing effective treatment plans for LBP and CBP patients—including the determination of which patients may be ill-suited for IVD replacement. This study of asymptomatic patients was conducted with the aim of understanding the prevalence of facet joint arthritis to help quantify the percentage of patients for whom facet injections are ineffective.

The Study

An approved review of archived CT scans of 100 total non-spinal patients was conducted using scans of 500 cervical facet joints from 50 subjects and 500 lumbar facet joints from an additional 50 subjects. All of the patient subjects’ medical records and scans were previously analyzed and evaluated as spinally asymptomatic for the purpose of this study.

The images were each graded and evaluated by an orthopedic spinal surgeon, neuroradiologist, and trained medical student on an independent basis. An additional three observers with separate clinical backgrounds also conducted a review of the facet joints to ensure no bias existed due to training backgrounds of the first group. The severity of facet joint arthritis symptoms were graded and statistical analysis was applied across different subject age groups. An average of all groups was then calculated using a coefficient.

The Results

Cervical Data

Of the 500 cervical facet joints from 50 patient subjects studied, asymptomatic cervical facet joint arthritis was evident in more than 33 percent of the scans. Nearly 60 percent of these patients showed only mild narrowing of the joint space and irregularities. About half of the subjects over the age of 40 demonstrated signs of arthritic changes. There were fewer “normal” or non-degenerated facet joints in patients in the aging (over 45) subject population. The prevalence of degenerative changes increased at all cervical levels in the aging subjects.

In all age groups, greater changes occurred more prevalently in the caudal spine area. At the C6-C7 spinal level, 78 percent of patients over-40 demonstrated facet joint arthritis. At the C2-C3 level, however, only 29 percent of the patients of the over-40 age group showed arthritic changes.

Lumbar Data

Thirty-seven percent of the patient subjects in the lumbar data group demonstrated asymptomatic lumbar facet joint arthritis, and up to 2/3 of these subjects showed grade 1 changes. As with the cervical data set, the lumbar set demonstrated a positive correlation with aging (over 45) and arthritic changes and degeneration of the facet joints. Caudal levels (L5-S1, for example) were more likely to show increased arthritic degeneration compared to cephalad levels. Only 12 percent of the patients over 50 years old showed changes at the L1-L2 levels, while 54 percent demonstrated these changes at the L5-S1 level.

Lumbar Spinal Stenosis Model

Conclusion

This study found a statistically significant positive correlation between aging and asymptomatic arthritic changes and degeneration of the facet joints of patients over the age of 45. These changes were evident at all spinal levels but were most prevalent in the lumbar facet joints and the C2-C3 and C6-C7 levels of the caudal spine. Approximately one third of the patient population in this study were found to have evident facet joint arthritic changes that were asymptomatic and associated with aging. When considering motion-preserving spinal implants, the age of the patient should be considered, as the treatment may not be as effective in patients over the age of 45, who are more likely to have or develop asymptomatic facet joint arthritis—a contraindication of the implant procedure.

 

 

 

 

Radiculopathy

A study 1 compared different treatment efficacies in two groups of patients with degenerative spinal disease-related buttock pain and found that the group receiving a selective nerve root block had clinically-significant improvement outcomes at post-procedure through 6-weeks, compared to the group that were treated with a facet joint block. This suggests that the cause of spinal-related buttocks pain is most likely radiculopathy, rather than facet joint degeneration.

What’s at Stake?

Many patients with spinal stenosis complain of back pain, buttock pain, or pain radiating from the buttock to the lower legs. As it is assumed that nerve root inflammation can contribute to lumbar and lower leg pain radiating from the spine, a common and frequently effective treatment may involve steroid or procaine injections. Selective nerve root block is used effectively in the treatment of degenerative scoliosis and has been demonstrated to be a successful form of short-and-long-term treatment for the pain. Similarly, a facet joint block has been used as an effective treatment for buttock pain, post-procedural lumbar pain, and morning stiffness associated with spinal degeneration.

Though various treatments have proven effective in alleviating or reducing pain in a percentage of the spinal patients receiving injections and blocks, the exact etiology of spinal-related buttock pain and radiating pain remains unclear. Because of this, uniform diagnostic and treatment guidelines for buttock pain—especially without concurrent radiating lower leg involvement—have been difficult to establish. This study links positive treatment outcomes with a more definitive diagnostic cause of buttock pain and seeks to contribute to the diagnostic and treatment criteria of buttock pain discussion.

The Study

Researchers treated 146 male and female patients presenting with spinal-related buttock pain without lower leg radiation by one of two methods—a) selective nerve root block (76 patients), or b) facet joint block (70 patients). The mean age of patients in both groups was 65 years. Both groups shared similar demographics when it came to age, sex, and health. Each of the patients was evaluated prior to their procedure and on day one, week 2, week 6, and at 12 weeks post-procedure. Their evaluation results were compared by their group injection method, and the results were then analyzed.

Results

On the DAY 1 post-procedure analysis, 7 percent of the patients in the nerve block group (GROUP A) were shown to have experienced an “excellent” response, and 6 percent of those in the facet joint block group (GROUP B) had an “excellent” response. In GROUP A, 46 percent of the patients treated showed a “good” response to the treatment, while only 13 percent of the patients in GROUP B had a “good” response.

At the two-week post-procedure follow up, 11 percent of the GROUP A patients demonstrated an “excellent” response, with only 4 percent of the patients from GROUP B had an “excellent” response. Similarly, 41 percent of the GROUP A patients were classified as having experienced a “good” response, compared with only 20 percent of those in GROUP B.

At the six-week post-procedural follow up, 11 percent of the GROUP A patients were classified in the “excellent” response group, while only 7 percent from GROUP B had this distinction. Forty-one percent of the patients from GROUP A demonstrated a “good” response, and only 20 percent of the GROUP B patients had a “good” response.

At 12-weeks, 47 percent of the GROUP A patients were classified in the “good” response category, and 46 percent of those in GROUP B experienced a “good” response to the treatment.

Conclusion

Researchers in this study sought to identify the cause of buttock pain associated with spinal stenosis. Specifically, they used a retrograde methodology to discover if the buttock pain was radiating pain or caused by facet joint degeneration. They treated two groups of patients using either selective nerve root block or facet joint block, and the data collected and analyzed indicates that the selected nerve root block was more effective through post-treatment follow ups through 6 weeks. The implication of this data suggests that spinal-related buttock pain is most likely caused by radiculopathy, rather than facet joint degeneration.

IVD Problems, Disc Degeneration

A study 1 of how dietary advanced glycation end-products (AGEs) effect the structure and function of intervertebral discs (IVDs) in male and female mice concluded that high dietary AGEs impaired IVD collagen quality, altered annulus fibrosus (AF) organization and changed the biomechanical properties of female IVDs, while having no clinically-significant effect on male mice subjects. The results of the study suggest the importance of targeting AGEs in spinal health assessments and treatments of female patients—particularly those at risk for, or suffering from, Diabetes Mellitus (DM).

What’s at Stake?

Structural disruption and chronic inflammation of the IVD is one of the leading causes of back pain, disability, and lost work wages worldwide. The many contributors to IVD damage and degeneration include DM and obesity, conditions that are increasing rapidly across the globe. Obesity increases the risk of IVD herniation, spinal stenosis, chronic inflammation, and other complications of the spine. It is also associated with an increased risk of cardiovascular disease, stroke mortality, and heart attacks–particularly in women. Since AGE accumulation is known to cause complications in populations with DM, this study investigates the effects of a high AGE diet on the IVD and how sex-differences may play a role in sex-specific IVD changes and disruption.

The Study

The subjects of the study were 21 male and 23 female recently-weaned mice, separated by sex and assigned to two groups. One group received a low-AGE diet (chow), and another group was fed only high AGE chow, which had been subjected to high-temperature heating. Each subject represented a third-generation off-spring of maternal mice fed only the respective diet used in the study groups, to exclude any effects of maternal AGES on the newly-weaned experiment mice.

The high AGE chow was representative of the typical Western human diet, with 80 percent higher AGE values than those of the low AGE chow. An increased AGE content is typically caused by thermally processing (extreme heating) the foods prior to ingesting. Examples of this include microwaving or deep-frying foods.

The feeding study lasted for 6 months, after which time the mice were sacrificed, dissected, and prepared for biomechanical IVD testing through Western blot analysis. Fasting glucose and total serum AGE levels were measured and quantified, and proteins were extracted, buffered, and sonicated. A single freeze-thaw cycle was used prior to biomechanical testing to avoid the process influencing the IVD mechanics. Axial compression-tension and torsional tests were performed on caudal motion segments, and the IVD diameter measurements were taken using a caliper. Assessments of IVD morphology, collagen molecular properties, and fiber orientation were created, measured, compared, and analyzed.

Results

The Western blot data showed a significant accumulation of AGEs accumulation of the IVD problems of the female mice fed the high AGE (H-AGE) diet compared to those fed the low AGE (L-AGE) diet. There were no changes in the IVD AGE levels or serum samples of the male mice in either feeding group. The results indicate that even without the presence of DM or obesity, dietary AGEs are likely to systemically accumulate in the IVDs of female mice—but not in males.

Further, the H-AGE female mice IVDs showed increase stiffness and torque-range, while the date on the L-AGE female mice showed no such correlation, and the male mice IVDs of both feeding groups were unaffected. This indicates that motion segment behaviors of female mouse IVDs—but not male mouse IVDs— are negatively affected by the H-AGE diet.

In addition, the AF organization and collagen fibers of H-AGE diet female mouse IVDs—but not male mouse IVDs— appeared compromised, particularly in the anterior AF. The H-AGE diet also appears to have contributed substantially to AGE accumulation and collagen damage in the AF of the female mice subjects but not the male mice subjects.

Conclusion

The results of this study, combined with previous study literature, suggests that female mice are negatively affected by a H-AGE diet, which appears to increase glycation within the AF collagen matrix and damage collagen and molecules in the IVD. High IVD crosslinking and collagen damage can contribute to biomechanical changes in the IVD and disrupt form and function in the unit. It appears that high AGE diets may increase these risks in female spinal tissues. Future research is needed to investigate ways to promote spinal health through dietary interventions to lower AGE levels, particularly in at-risk populations. This includes patients suffering from obesity and DM, especially females.

 

 

 

 

 

intradiscal, endplate

A study 1 on the efficacy of intradiscal biologic therapy, where new cells or genes are implanted into the degenerated disc matrix to reduce inflammation and increase matrix cell production, found that degenerated discs may not have the necessary nutrient transport capabilities to ensure proper disc nutrition during this form of therapy. The authors of the study emphasize the importance of research into the determining factors influencing disc cell nutrient transport in informing targeted treatments and strategies to improve disc nutrition in degenerated discs.

What’s at Stake?

Disc degeneration (DD) is a chronic condition that causes spinal pain in aging adults worldwide. The process of DD involves biomechanical modeling of the entire disc matrix and frequently leads to surgical intervention to remove the offending disc and restore functionality to the spine. For many patients, surgical procedures are unsuccessful, however. A noninvasive treatment that has demonstrated recent promise involves regenerating the DD by injecting it with genes, growth factors, small molecules, or implanted cells. These procedures are intended to reduce inflammation and catabolism and assist in the creation of a new disc matrix. But a cell-rich disc requires increased nutrients, and the cartilage endplate (CEP) of the DD may not have the capacity to deliver these nutrients to the matrix. In this study, researchers examined the effects of CEP transport properties in DD on nutrient diffusion and cell function and survival.

The Study

In order to isolate the variable of how nutrient supply affects the nucleus pulposus (NP) cell function, the researchers involved in this study mimicked the in vivo, diffusion-poor disc environment by creating diffusion chambers with similar parameters to isolate the NP nutrient supply mechanics. The cells of the NP receive nutrients that are diffused through the CEP matrix. Cells at the center of the lumbar discs can be up to 10mm from a capillary, while other cells can be just beside a CEP.

Researchers provided glucose and oxygen to cultured NP cells within the chambers. These nutrients were delivered through diffusion from human CEP’s from the open sides of the chamber. Metabolites were expelled into the culture medium by CEP diffusion. The functioning and survival of the cells require a balance between CEP transport properties and cell density, allowing for the request and supply of nutrients. The researchers reproduced the disc matrix environment and physiologic transport conditions in their CEP tissue cultures and diffusion chambers to monitor the effects of NP cell viability and gene expression across the different conditions of nutrient transport.

Specifically, intact human CEP’s from human cadaveric lumbar spines were used for the study. Full-thickness samples of the CEP’s and surrounding calcified cartilage were frozen and sectioned. The researchers calculated the diffusivity of each full-thickness CEP sample through fluorescence and photo-bleaching and using the Axelrod method. They measured each CEP’s biochemical composition spatially via imaging. They created special maps of the collagen, aggrecan, and mineral-to-matrix ratio of the CEP samples with the highest and lowest diffusivities. They measured CEP thickness with photomicrographs and then determined the average measurement across the five chambers.

Bovine NP cells were used in the study (similar to human NP cells). Post-incubation cell viability was determined using a cytotoxicity assay involving gel-stains and low-magnification imagery. Each L4-L5 donor CEP was analyzed for cell density and the anabolic and catabolic gene expressions were examined after chamber incubation. A regression model of fluorescence intensity was used to determine the NP cell gene expression and distance from the CEP. Spatial fluctuations of the CEP composition were described based upon regression models.

Results

The diffusive transport of nutrients varied widely between the CEP samples, affecting the function, health, and survival potential of the NP cells. In fact, there was a four-fold variation in small solute diffusivity in our human CEP sample array. Those allowing less diffusive transport reduced the supply of nutrients to the NP and shortened the viable distance within the diffusion chambers up to 51 percent with typical cell density. Those permitting poor diffusion seemed to downregulate anabolic and catabolic NP cell gene expression. This may mean that a reduced number of disc cells are capable of being sustained through low nutrient CEP diffusion, and the cell’s ability to retain its matrix homeostatic condition is hindered.

When we increased cell density, there was a reduction in cell viability caused by the CEP transport properties, though increasing cell density should raise nutritional demands and shorten the viable distance.  The CEP’s in our study that exhibited low diffusive transport were unresponsive to doubling the cell density, perhaps because they did not provide enough nutrient diffusion to nurture the cell.

We imaged the CEP’s to identify any differences between those with low or high intradiscal diffusivity. Our data found that those with low-diffusivity (and shortened viable distance) contained more collagen and aggrecan, mineral, and lower cross-link maturity. This could explain the blockage of solute penetration and diffusion. At any rate, there appears to be a strong correlation between NP cell survival or function and the availability and mobility of the nutrient supply in the CEP. Compositional defects with the CEP matrix can inhibit nutrient diffusion and undermine biologic therapies that depend upon an increased supply of nutrients to the cell matrix to succeed.

Summary

Our findings suggest that the composition of CEP can contribute to or detract from the function and viability of NP cells. Deficits within the CEP matrix can cause poor nutrient diffusion and block solute passages. This can cause an abundance of collagen and aggrecan, as well as mineral, and lower cross-link maturity. When cell density is increased, CEP’s developed transport deficits, decreasing the cell’s viability. It appears NP function and survival are dependent on the proper CEP composition, as an imbalance in this makeup can reduce the supply of nutrients to the cells, reducing the success rates of biologic therapies.

 

Spinal manipulation, DDD

A follow-up MRI study 1 of how non-specific lower back pain (LBP) patients responded to spinal manipulative therapy (SMT) showed that, while there were no significant differences in spinal degenerative features across responding and non-responding groups studied, the non-responding patient group appeared to have more severe degenerative features and lower baseline ADC values in their MRI scans than those who responded well to SMT. The study indicates that patients who respond well to SMT have fewer degenerative changes in posterior joints and disc diffusion than those who do not respond positively to SMT. The study suggests that treatment for patients with extreme degenerative changes should be tailored to address their LBP, as SMT may not provide a desired outcome for their condition.

What’s at Stake?

LBP –in particular, non-specific LBP—is one of the leading causes of disability and lost income potential across the world. Though SMT has been proven an effective form of treatment for many patients with non-specific forms of LBP, not all patients respond favorably to spinal adjustments or report satisfaction with their levels of pain relief and physical comfort, post-SMT. While many patients demonstrate measurable clinical improvements after 1 -3 SMT treatments, a subset of non-specific LBP patients do not respond to SMT. A previous study demonstrated a reduction in spinal stiffness, improvements in modality and an increase in lumbar multifidus contraction, and water diffusion at the L4-L5 disc level in a group of SMT responders after one week of treatment, while these benefits did not manifest in a group of non-responders or a control group. The current study was conducted to use MRI to look for significant differences between responders and non-responders that might account for the discrepancy in SMT outcomes.

The Review

A secondary analysis of the original non-randomized clinical trial involving subjects between 18 and 60 years of age who experienced non-specific LBP with an intensity of at least 2 on an 11-point scale and at least 20 percent on the modified Oswestry Disability Index (mODI) was conducted. Exclusion criteria included prior lumbar surgery, scoliosis, pregnancy, SMT within the past four weeks, and spinal tumors, fractures, or any issues that might exclude the subject from MRI scanning.

The 32 subjects attended three sessions—the first, with an MRI scan and standardized SMT, the second, with SMT only, and the third, where an evaluation of their mODI score, spinal stiffness, and multifidus function was analyzed. No SMT was performed at the last session. Subjects with greater than 30 percent improvement at the third session within one week were deemed “responders.” Those with less than 30 percent improvement were considered “non-responders.”

MRI findings were graded on a 4-point scale of joint degeneration and clinical value. Considerations included space between joints, osteophyte presence, hypertrophy of the articular process, subchondral cysts, and subarticular erosion. Other spinal irregularities were also analyzed and graded on subsequent rating scales.

Results

Baseline spinal structure demographics were similar across the board for all subject groups. A total of 15 subjects were labeled as “responders” based on the mODI scores, and 17 were considered to be “non-responders” to the SMT. The non-responders had more disc degeneration in their facet joints, as seen in the MRI scans. IVD and MC grading was similar in both groups. There was a higher prevalence of degeneration in the L4-L5 and L5-S1 levels in those with disc degeneration. Modic endplate changes were more prevalent in the non-responder group, at 58 percent (46.7 percent in the responder group).

Baseline ADC mean measurements and post-SMT disc diffusion responses varied between the two groups, with the lower scores of non-responders suggestive of higher rates of L4-L5 disc degeneration—a potential source of pre-and-post-treatment pain. The limited mobility of the degenerated discs could also be a factor in the non-responder group’s outcomes. The authors of the review suggest further studies with a larger sample size be conducted in the future to investigate the relationship between spinal degeneration, SMT response, and lower back pain.

The review did find beneficial post-SMT ADC level increases in the group of responders with LBP that suggests the therapeutic value of spinal manipulation in improving disc diffusion in and around painful spinal segments. However, 26 percent of the responders with LBP had no significant change in the ADC levels, so the beneficial effects of SMT may have more to do with mechanical or neurophysiological alterations, rather than diffusion.

Pathologies that are not biomechanical in nature, including bone inflammation, are unlikely to respond to SMT, according to the study. The findings highlight that non-specific LBP is treatment-specific, since its origin may be caused by a number of different conditions. Therefore, the review’s authors caution against using a single SMT approach in treating all non-specific LBP.