At Dynamic Disc Designs, we believe research to be the foundation of our spine models so practitioners in musculoskeletal health feel confident in the use of an accurate model while they educate patients about their findings.  Historically, models have been inaccurate and most critically, static, making it very difficult for the doctor to be convincing to the patient in the accuracy of diagnosis.

Research is at the roots of any practice. It fuels practice guidelines and directs both the patient and practitioner down the best path of care. Our models help support that voyage. We have worked hard to bring the best to practitioners of musculoskeletal science by scouring databases of spine science, to arrive at the most accurate model for teaching possible.

With over 1000 papers read in full text, Dr. Jerome Fryer leads the way by making sure our models are keeping up to the standards of best evidence. Weekly literature searches on keywords that surround musculoskeletal health are at the core roots of Dynamic Disc Designs.

Synovial fold, tag, meniscoid

Synovial Fold Release and Joint Cracking : a New Hypothesis for the Sound Generator has been created

In 2013, much work on simulating the synovial joint was conducted and led to in-vitro testing using ddd models to demonstrate the sound.
The mechanism of a cracking joint sound was produced with two factors in place.  The precursory details required to create the environment to produce the sound of an audible release were:

polished simulated cartilage surface and elastomeric simulated synovial fold. No fluid or gas was required.
  1. Negative pressure was required to induce the noise
  2. Negative pressure was required to re-produce the noise
  3. Different sound characteristics (differing tones) were observed when different material properties were used for the fold—both in size, shape and intrinsic qualities (ie., elongation, tensile strength and durometer).
Points to support this suction release phenomenon in a vitro testing environment.
  1. The noise generated from a suction cup release is not a gas rushing into the negative space but the elastic recoil of the cup material itself.
  2. This noise is generated both without fluid (in air) and in fluid (in water). This provides support that the sound is irrespective of the environment and more related to the elastic properties of the simulated fold.
Other points.
  1. Audible releases have different sound signatures. Not all events are identical.
  2. Audible releases of differing synovial joints make different sounds. For example, a 5th MCP joint makes a different sound when distracted when compared to the 1st MCP. This is believed to be due to the shape of the fold/hyaline interface.

Clinical translation? Once we begin to identify the process of the noise generator, this will help lead us to better understand the pressures in and around the cartilage to improve mechanobiological therapies.

Core Muscles of Spine

Understanding core exercises and why they can work for many mechanical low back pain suffers may not be such a mystery.

At Dynamic Disc Designs we believe that the answers may not be as complicated as thought. In a publication titled, ” A Meta-Analysis of Core Stability Exercise versus General Exercise for Chronic Low Back Pain  ” the authors looked at RCT studies and compared regular exercise to core stabilization exercises in short term and long term outcomes of low back pain. They found a significant difference with the core stabilization for the short term but not so much for the long term outcomes.

What defines a core exercise? What is the core? And what is actually occurring in the spine during the core exercises? These are questions that are just starting to be asked. Some believe that core exercises have no scientific backing. You can read more here.

At Dynamic Disc Designs we believe that the true core of the spine is the nucleus pulposus. Core stabilization exercises often are done recumbent, and often works to brace the lumbar spine to facilitate nuclear intradiscal centralization, decreasing sensory afferent stimulation to free nerve endings in the disc. This often stabilizes the facet joints which is also thought to be a pain generator as well.

Dynamic Disc Designs manufactures models to help in the discussion of pain generators and strategies to improve the understanding of positive (and negative) clinical outcomes.

Sinuvertebral nerve

Pathomechanisms discogenic pain have been discussed in many pockets of research.

Accepted by The Spine Journal this month, researchers titled the manuscript Pathomechanisms of discogenic low back pain in humans and animal models and came up with some pretty interesting findings and conclusions. Their paper discusses how prevalent low back pain is in the public. They then move onto topics that include the distribution of sensory nerves in the intervertebral discs, inflammation, and the aspects of hypermobility.

One of the important topics they discuss is the nerve ingrowth into the intervertebral disc. Many people now believe that it is the sinuvertebral nerves that contribute the most in the development of low back pain. The outer third of the annulus fibrosus is thought to house the nerves of the disc but when the discs get damaged, these nerves grow into the inner two thirds of the annulus–making them more pain sensitive.

These researchers concluded that the best way to prevent low back pain is to prevent sensitization of these sinuvertebral nerves as well as prevent IVD hypermobility.

ddd produces models that demonstrate the sinuvertebral nerves as well as neoinnervation within radial tears. Because of the their dynamic disc, spine professionals can show the innervation of the disc while at the same time demonstrate hypermobility.

annular fibres angles

In a recent paper published in Arthritis and Research Therapy, researchers showed how mechanical disc strain causes inflammation.

Mechanical factors have always been a suspected cause of spinal problems. These factors include moving the spine in a direction with either too much force and in combination with the wrong direction. Intervertebral discs are designed to withstand significant load but they do have limits. Whether someone lifts too much with the wrong posture, or if someone over-challenges their discs repetitively, Dynamic Disc Design models can help deliver this important clinicial education message.

In the research paper titled, High mechanical strain of primary intervertebral disc cells promotes secretion of inflammatory factors associated with disc degeneration and pain, these researchers showed that the cells within the disc respond in an inflammatory way by secreting factors that promote degeneration and low back pain. They also concluded that disc cellular strain produce elements that likely facilitates neoinnervation and respectively, discogenic pain.

Spine Models to Help Improve Outcomes

Spine Models to Help Improve Outcomes

Dynamic Disc Designs spine education models help explain mechanical factors to patients in a platform to improve clinical outcomes through teaching avoidance behaviors that contribute to ongoing intradiscal inflammation. Our Professional LxH Model features a dynamically bulging disc as well as neoinnervation to radial tears. Our Circumferential Delamination Model explains intradiscal pain. Explore how ddd can make a difference.

Acidic stained nucleus modeling

Disc height loss is a radiological finding that must be considered in the diagnosis of back pain.

Disc height loss is an important finding. Dynamic Disc Designs Corp. manufactures dynamic disc models to help demonstrate pain generators of disc height loss.

In a recent publication in Global Spine Journal the authors proposed a novel ratio to determine which discs are painful in MRI imaging.

In the manuscript titled, Novel Imaging of Intervertebral Disk and Pain, these researchers looked at two factors that they believed to be the most important in determining whether a disc is symptomatic or not. They proposed that it is the ratio of T1 rho and disc height that plays a promise in identifying painful discs and could possibly prevent the invasive discography procedure. ddd congratulates these authors.


Lumbar disc model

Animal disc models are a challenge. Understanding how we, humans, compare to our animalistic counterparts is a touchy subject. This month, some researchers looked at animal discs and compared them to human tissue.

Zhang et al. titled a manuscript : Histological Features of Endplates of the Mammalian Spine : From Mice to Men, and looked carefully at the micro-architecture of the disc endplate. They found significant differences between the species they compared. Of the animals they compared ( mouse, rat, rabbit, and goat) they found the mouse and rat had very little bony components to the endplate while the rabbit and goat had growth plates adjacent to the bony endplates. When compared to human, the human endplate had much thicker cartilage and  the growth plate exchanged for trabecular bone.

Animal disc models are a challenge to use in research. They are useful because they are easier to access, simpler to obtain review board of ethics approval and often cost effective. But reseachers must understand that extrapolating their findings to the human should be cautionary. Zhang et al. showed in this research that although animal discs are similar to humans in many ways, significant differences exist. In general, animal endplates have more hyaline cartilage while humans have more calcified cartilage.

Dynamic Disc Designs is a spine modeling company that highlights important research. We are constantly on the lookout. Endplate modeling is available.

Patient education models

Discs are often at the core of spinal problems. Halloween is approaching and there isn’t a better time to highlight the importance of creep and disc bulging.

Many clinical symptoms related to spine present themselves in a time dependent fashion with patients often complaining of pain after a period of time standing or sitting. And very often when asked, they can tell physicians how much time needs to elapse before the symptoms of pain present. In a recent article by Pei et al, they defined bulging to occur at a maximum radial rate of 2.78%±1.09. They concluded that disc creep is a very important biomechanical repsonse and can effect spinal function.

Dynamic Disc Designs continues to provide spine professionals with dynamic models to help explain and understand pain generators. Perhaps “where” it hurts, may not be that complicated.