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Cervical Spine Models

Dynamic Cervical Model

Cervical spine models, handcrafted to deliver the most accurate of spine models to spine professionals.

Dynamic Disc Designs has been leading the way in 3d models for over 8 years now. Recently, at the request of the customers, Dr. Jerome Fryer (Chief Innovations Officer) decided it was time to construct a dynamic full multilevel cervical model.

With details extracted from real human cadaveric specimens, this latest multilevel cervical model includes the axis and atlas with the cruciform ligament. Upper cervical injuries are common in motor vehicle, work related, and sport accidents. Personal injury lawyers as well as surgeons and chiropractors have been utilizing Dynamic Disc models to educate the injuries.

With a dynamically designed intervertebral disc and ligamentum flavum, at the levels of C1-7, this new model includes the cruciform ligament and demonstrates hypermobility at C1-2. C6-7 shows a central disc herniation under load.

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Dynamic Disc Designs continues to listen to the feedback given from its customers in the push to deliver the best teaching tools to improve outcomes or settle cases in and out of court with personal injury cases. We have been a leader in teaching aids to help professionals connect with people in the discussion of spine pain generators in finding the most suitable treatment for each case. Ligament instability is a common outcome in motor vehicle accidents as our imaging strategies using upright MRI now allow us to see these conditions under dynamic spinal motion.

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Synovial Fold Release and Joint Cracking

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.

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Understanding Core Exercises

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.


Pathomechanisms Discogenic Pain

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.

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Mechanical Disc Strain Causes Inflammation

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.


Diagnosis of back pain

Detailed custom anatomical model

Identifying the anatomy of pain generators in the diagnosis of back pain should always be at the forefront of any workup.

Even though research has not helped us much in assisting physicians with reliable and valid orthopedic tests, that does not mean they do not exist. Dynamic Disc Designs(ddd) believes better initial physical exam workups can help with the identification of pain specific tissues. Dr. Jerome Fryer BSc DC, the founder of ddd, suggests dividing the the spine into anterior and posterior pain producers can simplify and aid the physician in the initial exam. Understanding the anatomical structures that are challenged with dynamic flexion and/or extension and how the patient responds when the pain presents can be a real clue in identifying the sensitive tissue.

He explains: If someone with back pain is guarded during the movement of active lumbar flexion and is only able to achieve 15 degrees, then quickly stops and utilizes the upper extremities by placing their hands on their thighs, Dr. Jerome Fryer would suggest that the unloading of the intervertebral disc is occurring with this avoidance behaviour. A painful intradiscal lesion should be in the differential. On the other hand, if a patient is able to move through the lumbar flexion but there is a “sore spot” in the middle of the range, one has to think about a painful facet as these facets glide on each other and translate anteriorly while approximating.”

These models were developed for patient education primarily but have also been developed to help in the differential diagnosis of painful anatomical spine structures. Spine doctors are finding them an invaluable resource for education.

  1. Anatomy
  2. diagnosis
  3. treatment

Disc height loss an important finding

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.