News for Dynamic Disc Designs which includes updated research and a synthesis of the most updated studies to help efficiently engage with patients and their back and neck pain.

We take an approach that an evidence-based practitioner would take. Carefully dissecting the history of a patients complaints, weaving the mechanical and psychosocial factors and then deliver a rational and tangible approach to relieving the back pain to the patient. Our news helps keep the practitioner abreast of the latest publications related to musculoskeletal health.

At our headquarters, we dedicate weekly hours to comb through the research for those who treat back pain and neck pain and deliver it.

LBP and Disability

A cross-section study 1, in Spine, was conducted to investigate the link low back pain (LBP) and disability had with the structural features of the thoracolumbar fascia. The results shared that a relationship existed between these factors.

The Context

While the Global Burden of Disease Study has researched LBP to be the leading cause of disability in humans, a lot of work needs to be done to fully understand the etiology associated with LBP. More research needs to be done to address all of the factors linked to LBP. Such understanding is crucial because it will help with creating targeted prevention strategies to help millions around the globe.

Previous research has analyzed LBP and disability to be associated with structural abnormalities of the lumbar spine. Furthermore, MRI has shown LBP to be linked to disc protrusion, disc degeneration, nerve root displacement or compression, and high-intensity zone. While more research is still needed, the present results do suggest that the issues of LBP and disability can be addressed by targeting structural factors. Take note, there’s evidence that suggests the thoracolumbar fascia may be linked to LBP. However, few MRI studies have examined such a link.

hypermobility-spine

The Study

The current study had an aim to examine the link present between the lumbar fascia’s length and LBP as well as disability. The study used MRI.

A total of 72 participants (49 females and 23 males) were recruited. They weren’t required to have any history of LBP or current LBP to participate. The MRI was performed, in this study, using a 3.0-T magnetic resonance unit (with the participants in supine position). The study administered the Chronic Pain Grade Questionnaire (CPG) at the time of the MRI.

The study used the Logistic regression analyses for examining any likely associations between fascial length and high pain intensity (or disability).

What did the Results Conclude?

The results of the study concluded that there was a significant association between a shorter length of fascia and high-intensity LBP and/or disability. Such association was after adjusting gender, age, and the body mass index. The association was strengthened after adjustment for the cross-section area (in the paraspinal compartment).

While more studies are required, the current results do suggest that fascia’s structural features likely play a role in disability and LBP.

Sacroiliac Joint

According to research, at least 10 to 30% of LBP or low back pain is linked to the sacroiliac joints. A review 1 in the journal of Best Practice & Research Clinical Rheumatology decided to give the said link a more in-depth look.

The Context
As mentioned, studies have shown an approximate 10-30% of all LBP being attributed to sacroiliac joints SIJ. While almost 44% of SIJ pain is associated with trauma onset, the etiology is still unclear. So, even today, there are numerous challenges when it comes to diagnosing as well as treating sacroiliac joints. One of the biggest challenges is determining whether or not pain or dysfunction in the human body is primarily due to the sacroiliac joint. SIJ being a causative factor, while theorized, doesn’t have a lot of evidence for support.

The Purpose of This Review

The current content aimed to cover the available data regarding the anatomy of SIJ along with its examination, etiology, and treatment to assist clinical approaches. One of the major questions dealt with: when pain is experienced at the SIJ, is it better to direct treatment at local tissues, or should it focus on factors that are remote to the joint?

Furthermore, the review also wanted to analyze if the pain in a region was primarily due to SIJ or were other factors in place (on and around the said joint)?

The review went over the anatomy and function of the Sacroiliac joints, the etiology of Sacroiliac joint dysfunction, the clinical assessment of the SIJ, and managing SIJ pain.

The review tried its best to consider all of the complexities associated with SIJ’s diagnosis and management (including sport and exercise-related SIJ pain). It took a bio-psycho-social perspective.

What did the Review Find?

The review summarized that clinicians and researchers shouldn’t conflate sacroiliac pain, stability, and dysfunction (as all three are separate). Furthermore, trauma and repeated training might be associated with SIJ pain in athletes.

Clinical evaluations should administer clustered pain provocation testing. Such a suggestion was made after determining that palpation and mobility test didn’t offer any proven value. When addressing persistent pain, taking a bio-psycho-social approach is crucial. Treatments (backed by evidence) included pelvic compression belts, surgery, manipulation, exercise, and corticosteroid injections.

Also, further research is required for understanding SIJ pain better.

 

A review article 1 in Spine Surgery and Related Research presented an interesting overview of the molecular mechanisms involved in the degeneration of intervertebral discs. The review also described certain molecular targets and therapies that may help with intervertebral regeneration and repair.

Why do such a Review?

Even though life expectancy has increased over the past century, it isn’t without a share of medical issues. According to research, neck pain and low back pain (LBP) tends to increase with age. They’re also the 1st and 4th leading causes of disability in humans, respectively. Furthermore, intervertebral disc degeneration (IDD) plays a significant role in generating back pain. That’s why it’s important to understand the degeneration of healthy joints (especially intervertebral discs or IVDs) with age to improve quality of life.

One of the first tissues that experience degeneration in adults is the IVD. While there’s still a lot to learn, the current review was conducted to share some of the molecular pathways and cellular changes that tend to lead to IDD.

molecular mechanisms

What Did the Review Cover?

The objective of the current review was to offer an overview of the known molecular mechanisms leading to IDD. The review was sure to address the complex interactions of endogenous and exogenous stressors. It focused on the degeneration of the extracellular matrix (of the nucleus pulposus and the annulus fibrosus).

Furthermore, the review also went over the supporting role played by the DNA and intracellular damage, oxidative stress, cellular senescence’s catabolic effects, as well as the inappropriate response by the cells to damage. All of the data can prove to be beneficial in understanding how physical and chemical changes can increase the spine’s degeneration. The review also shared certain therapies for spinal regeneration and repair.

What was Concluded?

The review shared that there’s potential to discover novel disc degeneration mechanisms by focusing on disc functions that help maintain stability as well as motion of a mechanically loaded structure in a nutrient-poor, acidic, and hypoxic environment.

It was important to note that disc degeneration is influenced by the degeneration of adjacent spinal structures and systemic factors. That’s why researching the entire spine is essential for the progress in the spine’s degeneration and regeneration therapies. Also, early intervention (before the functional failure of the spinal disc) is crucial.

lumbar disc herniation

A study investigating kinematic changes in subjects with lumbar disc herniation (LDH) performing five activities of active daily living (ADL) found that LDH patients were more apt than healthy subjects to restrict the lower lumbar (LLx) and upper lumbar (ULx) spinal motions when performing ADLs. The LDH patients used pelvic rotation to compensate for their reduced lumbar flexibility and increased pelvic tilt and lower extremity flexion during problematic ADLs. 

What’s at Stake?

Lower back pain affects up to 85 percent of the worldwide population—especially those over 40—and can contribute to musculoskeletal problems when the lower spine and its surrounding structure is overloaded. Because LBP patients often restrict musculoskeletal motions during ADLs to avoid pain, understanding the kinematic idiosyncrasies of LBP patients during their ADLs is essential when treating spinal issues through physical therapy that involves gait and functional training. 

Past research has indicated LBP patients had less transverse plane movement than healthy subjects during level walking exercises. One study found that LBP subjects were more likely to exhibit spinal or pelvic rotation, while another study came to the opposite conclusion but found that LBP patients had less range of motion (ROM) in the lumbar spine than the control group. Conflicting studies have concluded that LBP patients had significant reductions in the range of hip flexion and spinal movement across all three planes during trunk flexion or better ROM in the lumbar spine, with more restriction in the pelvic or thorax ROM. The divergent conclusions are likely due to the trunk and whole lumbar being considered a single, rigid segment, rather than interconnected segments that operate independently. The prior studies may also have neglected to consider the kinematic differences among LBP patient subgroups. Analyzing the variability of joints and segments is vital when studying LBP patients and their unique kinematics. 

This study focused on how lumbar disc herniation (LDH) specifically contributes to LBP, including the lower trunk, thorax, hip, and pelvis. The goal of the study was to use a computing model to study LBP patients with LDH and understand their pain-related modulation of their lower extremities and multi-segmental trunk kinematics during level walking, stair climbing, trunk flexion, ipsilateral pickup, and contralateral pickup. 

The Study

Twenty-six healthy males with a mean age of approximately 24 years and seven LHD diagnosed male patients who were, on average, approximately 28 years old participated in the study. The disc herniations occurred at L4/5 in three of the LDH patients, L5/S1 in three cases, and at both locations in one patient. 

The motion of thorax, ULx, LLx, pelvis, hip, and knee were tracked via 3D active markers placed in various locations on the subjects’ spines, pelvises, thighs, and shanks. All the markers were placed by a single surgeon, who had previously demonstrated the five ADLs the subjects were to perform. After practicing the motions a few times, the subjects repeated them while data was collected through the active markers. 

The kinematics of the thoracic segment, ULx, LLx, pelvis, hip, and knee were calculated using a modified Gait-full-body computing model that would analyze the motion of each lumbar vertebra using at least three markers. The kinematic spine and hip angles were analyzed with the computing model using a Euler rotation sequence of spinal segments or thigh/pelvis movement, and the thoracic segment as it related to the L1 vertebra. The ROM for all segmental or joint angles during flexion-extension or gait cycles across all three planes in three planes was calculated, and data analysis was performed using a custom program. 

Results

The LDH subjects had much more pelvic rotation and LLx rotation than the healthy subjects during level walking. The LDH group had much less ROM for thoracic flexion, pelvic tilt, and hip abduction during stair climbing, but they showed more ROM for LLx rotation. No clinically significant variance was noted between the two groups for thoracic flexion, trunk flexion or ipsilateral and contralateral pickups. Lumbar flexion ROM was significantly decreased in the LDH group—especially for ULx with nearly no sagittal angular displacement.  

The findings suggest that people with LDH modulate their movement patterns and motor regulation in response to, or avoidance of pain. There were evident kinematic differences between the healthy subjects and LDH patients in this study. LDH patients had more pelvic rotation and increased LLx rotation during level walking, contradicting earlier studies where patients had less than or similar pelvic rotation when compared with healthy subjects. The use of different marker sets, study methods, computer models, and speed of motion might account for the varying test results, but it appears that pelvis and LLx motions in the transverse plane may have a more pronounced effect than that of the other two planes during LDH abnormal motion level walking analysis. 

Conclusion

In regard to the direction or range of motion, there were contrasting kinematic characteristics and different adaptations to LDH between the ULx and LLx in this study. The thoracic motion did not appear to be affected by the LDH when subjects were performing the ADLs, with the exception of stair climbing. During all five ADLs the LDH patients maintained limited lumbar flexion, and their pelvises, knees, and hips compensated for the lost lumbar motion capacity in the sagittal plane during contralateral pickups. In four of the five ADLs (the exception being stair climbing), the LDH patients increased their pelvic rotation significantly. They also had higher rates of antiphase movement between thorax and pelvis in the two pickups and in level walking and stair climbing in the transverse plane between ULx and LLx.

The findings of this study should help provide a more comprehensive understanding of how LDH influences kinematics and lead to more specific treatments and better therapeutic outcomes for LDH patients. 

disc height

In this Spine Education video, Dynamic Disc Designs’ Dr. Jerome Fryer demonstrates the benefits of helping lower back pain patients better understand their condition by using dynamic models and visual aids.

“How often do you encounter a patient that explains that their symptoms are worse as the day progresses?” he asks.

Though clinicians understand the key to a graduating pain syndrome involves a complex biomechanical and biochemical matrix in the spine, back pain patients don’t need extensive medical knowledge to appreciate the dynamics of what is happening in their bodies. A simple visual aid can help clarify and simplify their predicament and potential solutions.

 

Hands-On Demo of Diurnal Expression of Fluid from the Disc

Using a dynamic disc model, Fryer demonstrates the diurnal expression of fluid from the disc as the disc height changes over the course of the day.

“We know that the disc height is tallest in the morning,” he says, holding a fully expanded disc model to the camera and then slowly squeezing the dynamic model to demonstrate the loss of height that occurs throughout the day.

“As the day progresses, the disc height will slowly lose its height [causing the facets] to imbricate or shingle. If a patient [complains] their symptoms are more present as the day progresses, you [use] this graph 1 to demonstrate what’s happening in their spine.

“As the person gets up in the morning, there is a quick change in the disc height in the first 10 minutes,” he says, pointing out a steep curve on the graph.

“As the day progresses, the disc height is lost.”

Annular Disruption in Degenerated Discs Reduce Capacity to Maintain Height

Fryer says the situation can be even more extreme when a patient is suffering from degeneration in the disc because the disc can no longer hold its full height, due to disruption in the annulus.

“Helping patients understand symptoms as the day progresses will help them understand why it hurts,” he says. “That gives you more empowered strategies to help patients get motivated, if its posture, or even recumbency, or exercise, or getting out of a chair to help with the disc height changes. These dynamic disc models are very powerful in helping patients with self-awareness.”

For more information on dynamic disc models and patient teaching aids, visit Dynamic Disc Designs.

Zygapophyseal Joint Pain in Chronic Whiplash Patients

A study 1 of sensory hypersensitivity in patients suffering from chronic whiplash associated disorder 6 months or more after being involved in a motor vehicle collision (MVC) found that the hypersensitivity was reduced, and pain thresholds were increased after receiving a medial branch block (MBB) procedure of the cervical spine.  The results of the study indicate the cervical zygapophyseal joints most likely contribute to sensory hypersensitivity caused by peripheral and centrally mediated pain.

 

What’s at Stake?

A common problem of people who have been involved in MVC’s is chronic whiplash associated disorder (WAD). According to research, between 32-56 percent of those involved in MVC’s may continue to suffer from related disability or pain 6 months or longer after their accident. Research has implicated the cervical zygapophyseal joint as a possible source of chronic hypersensitivity in 54-60 percent of subjects with WAD—evidence that is supported across multiple biomechanical and neurophysiological studies. It is thought that tissues that had been seemingly unaffected by the MVC experience sensory hypersensitivity when the body’s pain processing mechanisms are altered in the spinal cord. This sensory hypersensitivity and central nervous system hyperexcitability decrease the pain thresholds in the body, creating an exaggerated response for thermal, electrical, or mechanical stimuli for WAD patients. The prognosis for WAD patients suffering from sensory hypersensitivity is poor, and better understanding of the phenomenon could improve long-term treatment outcomes.

The Study

 

The pretest-posttest exploratory study involved 18 volunteers (15 females, 3 males) with an average age of 45 years and who had experienced WAD for 6 months or longer, with numerous neck complaints, body tenderness, and decreased range of motion. A control group of 18 healthy patients (15 females, 3 males) with an average age of 45 years also participated in the study. A group of chronic WAD patients with pain reported for 6 months or longer and who had a minimum of 80 percent decrease in neck pain intensity following an intra-articular zygapophyseal joint block procedure also took part in this study. Exclusionary criteria included pregnancy, previous history of headaches or neck pain requiring treatment, central or peripheral neurological problems, coronary artery or peripheral vascular disease.

Researchers rated the subjects’ pain intensity levels on a scale of 1-10 before and after receiving MBB procedures. Quantitative sensory testing (QST) based upon pressure pain thresholds (PPT’s) and cold pain thresholds (CPT’s) were conducted on the control and WAD groups. All measures were recorded, including patient demographic variables and their current MVC litigation status.

Cold Pain Threshold Testing

A 30mm x 30mm thermode set to 32 degrees Celsius placed over the anaesthetized articular pillars of the cervical zygapophyseal joints measured cold pain thresholds in the test subjects as the temperature was decreased at the rate of 1 degree Celsius per second. Patients used a self-controlled switch to indicate when the sensation of cold turned to pain as each bilateral site was tested. (The minimum temperature was 1 degree Celsius.) The average values were gathered for analysis.

Pressure Pain Threshold Testing

The articular pillars of the cervical zygapophyseal joints, peripheral nerve trunk of the median nerve, and the tibialis anterior were measured in the PPT tests, with the subjects using a self-controlled switch to indicate when the sensation of pressure turned to one of pain. The tests were performed three times bilaterally on each site, with a pause of 10 seconds between each test. The average values were recorded and later statistically analyzed.

Cervical spine model to demonstrate zygapophyseal joints

Dynamic Cervical Model

Diagnostic Cervical Zygapophyseal Joint Blockade

The patient group with chronic WAD underwent two diagnostic zygapophyseal joint block procedures—one, prior to the study, where a spinal needle was inserted with fluoroscopic guidance into the joint while the patient was in the prone position. An injection containing a local anesthetic and a corticosteroid was made into the affected zygapophyseal joint. If these patients experienced a relief of pain intensity of at least 80 percent but their pain later returned, they received the second MBB injection. In this study, none of the patients were excluded from the second MBB, as each of them had experienced at least an 80 percent reduction of pain from the first procedure, with the return of pain post-procedure.

Results

The WAD patients demonstrated clinically significant changes in their sensory hyperactivity measurements after the blockade of the cervical zygapophyseal joint. These changes included a decrease in CPT’s and increase of PPT’s in the cervical spine and distal sites. This finding is unique in the study of chronic WAD patients and suggests that minimizing the source of pain—in this case, the zygapophyseal joint—may help modulate sensory hypersensitivity in chronic WAD patients, at least in the short-term. The study authors urge larger trials with long-term follow-ups of patients to gather more information and improve the treatment outcomes of patients with WAD.

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.