, ,

Osteoarthritis model – subchondral bone

osteoarthritis model, spine, facet, disc height loss

Osteoarthritis is a burden on the people of this world and a major cause of disability. It is considered a degenerative disorder, affecting the aging population as it erodes cartilage, disrupting subchondral bone, leading to osteophytosis, muscle weakening and inflammation to the structures within the joint. 1 An accurate osteoarthritis model would be very helpful for spine.

Historically, osteoarthritis has been looked at from the perspective of cartilage wear with newer insights and interest at the subchondral level. (sub = below + chondro = cartilage) In a paper published in Arthritis and Research Therapy, researchers gave special attention to the subchondral bone. 2

In the perspective of the spine, disc height loss has an influence on the facet joints which are synovial joints. 3 It is disc height loss (a measure of vertebra approximation or closeness) that has shown to have the greatest impact on the biomechanics of a spinal motion segment. In particular, it narrows the intervertebral foramen, causes disc bulging as well as annular stress, and the narrowing can have an effect on the vascular flow in and around the nerves that exit the spine directly influencing nerve roots. There are few other degenerative conditions that can have such a large impact effect on the musculoskeletal system. 4

In Figure 1. of Subchondral bone in osteoarthritis: insight into risk factors and microstructural changes 2 a beautiful histological image showcases the microanatomy of the: calcified cartilage, uncalcified cartialge, the subchondral bone along with the tide mark and cement line of a normal synovial joint. This is an important area of the facet joint.

osteoarthritis model

As mechanical stress is placed onto the uncalcified cartilage, stress will translate through this avascular structure and into the subchondral bone. Chondrocytes secrete glycosaminoglycans (GAGs) and collagen type II-rich extracellular matrix (ECM) that are essential for the maintenance and regeneration of the cartilage which acts to protect subchondral bone. 6 Articular cartilage is mainly water, contributing to 80% of its weight. 7 Interestingly, we have seen that there is a diurnal variation of the cartilage in cartilage 8 similar to what we see in the discs. 9

The bottom line is our tissues that marry our bones together are dynamic and are in constant change to mechanical forces. Disc height loss of the spine will cause the facet joints in the spine to compress and lead to arthritis if not carefully managed.

Dynamic Disc Designs develops models to help in the greater understanding of how a compressed disc can have a multitude of mechanical effects on a spinal motion segment. Understanding the load distribution as it occurs naturally with diurnal variation, lying down, or with injury lifting, or prolonged sitting can be of great assistance in managing the treatment of spinal osteoarthritis as a result of disc height loss and facet arthrosis. Patient education proves to improve outcomes of osteoarthritis when patients understand what not to do first and secondly, why it is important to continue to do safe exercise. 6

The Professional LxH Model demonstrates hyaline cartilage and perichondrial vascularization, while the Lumbar Spinal Stenosis Model demonstrates subchondral sclerosis helping in the education of facet osteoarthritis. A dynamic osteoarthritis model for spine is important to have if educating is a part of a physician’s clinical life.

“Helping doctors be better teachers”


  1. Grynpas MD, Alpert B, Katz I, Lieberman I, Pritzker KP: Subchondral bone in
    osteoarthritis. Calcif Tissue Int 1991, 49:20–26.
  2.  Li et al. Arthritis Research & Therapy 2013 2013, 15:223 http://arthritis-research.com/content/15/6/223
  3.  Arbit, E., Pannullo, S., 2001. Lumbar stenosis: a clinical review. Clin. Orthop. Relat. Res.(Mar), 137–143.
  4.  Disc height loss and restoration via injectable hydrogel influences
    adjacent segment mechanics in-vitro Christian Balkovec , Andrea J. Vernengo, Stuart M. McGill Clinical Biomechanics 36 (2016) 1–7
  5.  Li et al. Arthritis Research & Therapy 2013 2013, 15:223 http://arthritis-research.com/content/15/6/223
  6.  Blazek AD, Nam J, Gupta R, Pradhan M, Perera P, Weisleder NL, Hewett TE, Chaudhari AM, Lee BS, Leblebicioglu B1, Butterfield TA, Agarwal S. Exercise-driven metabolic pathways in healthy cartilage. Osteoarthritis Cartilage. 2016 Feb 27. pii: S1063-4584(16)01025-6. doi: 10.1016/j.joca.2016.02.004. [Epub ahead of print
  7.  The basic science of articular cartilage: structure, composition, and function. Sophia Fox AJ, Bedi A, Rodeo SA. Sports Health. 2009 Nov;1(6):461-8.
  8.  J Biomech. 2013 Feb 1;46(3):541-7. doi: 10.1016/j.jbiomech.2012.09.013. Epub 2012 Oct 24. Diurnal variations in articular cartilage thickness and strain in the human knee.Coleman JL, Widmyer MR, Leddy HA, Utturkar GM, Spritzer CE, Moorman CT 3rd, Guilak F, DeFrate LE.
  9.  Botsford, D. J. MD; Esses, S. I. MD, FRCS(C); Ogilvie-Harris, D. J. MB, FRCS(C)  In Vivo Diurnal Variation in Intervertebral Disc Volume and Morphology. Spine: April 15, 1994
  10.  Blazek AD, Nam J, Gupta R, Pradhan M, Perera P, Weisleder NL, Hewett TE, Chaudhari AM, Lee BS, Leblebicioglu B1, Butterfield TA, Agarwal S. Exercise-driven metabolic pathways in healthy cartilage. Osteoarthritis Cartilage. 2016 Feb 27. pii: S1063-4584(16)01025-6. doi: 10.1016/j.joca.2016.02.004. [Epub ahead of print
, ,

A Selection of Human Spine Models Make Patient Education Easier

Human spine models, modeling, anatomical models, patient education

A Selection of Human Spine Models Make Patient Education Easier


Most individuals don’t really enjoy going to their doctor, no matter what the reason, be it a routine checkup or for a problem that they’re worried might be serious. Some people get nervous at the mention of a doctor visit and others see their blood pressure spike when they enter any medical office. Experts call this “White Coat Syndrome”.

Why does this occur? One reason is very obvious. The patient is afraid that they’ve developed a serious disease. Unfortunately, sometimes that’s the case. But in many instances, the anxiety comes from the fear of the unknown. In other words, patients don’t know what will transpire when they’re in that office. For that reason, patient education that involves talking about what’s wrong and how it will be fixed is essential.

For chiropractors, who often deal with patients who are in severe pain, this education is super important and should be done on the first visit after an overall assessment is performed. The fact that this instruction is done at all is obviously essential, but how it’s done is even more important. In short, chiropractors who use human spine models to educate their patients produce patients who are more satisfied with their care and who are pleased that they can walk out of the office knowing the facts about their pain and what can be done to fix it.

Human spine models from Dynamic Disc Designs (ddd) are continuously touted as the best available in this category. That’s because they’ve been designed and crafted by an experienced chiropractor who starting making these models because he was frustrated by the tools available for patient education.

Spine modeling, human, spine, models

Posters, while perfect for decorating office walls, just didn’t do the trick. After all, it’s tough to portray a disc bulge via a flat picture of the spine. Dr. Fryer, the owner of ddd, also found that the static models available for patient education didn’t fit what he needed to help his patients. Though 3-dimensional, they didn’t move like the spine moves, making it difficult to portray any number of spine-related problems. That’s why his human spine models move, making it possible for a patient to truly grasp the workings of the spine and why theirs isn’t functioning properly.

Dynamic Disc Designs offers a large selection of human spine models. In the “lumbar” category, the most popular is the Professional LxH model, which includes a flexible and totally dynamic herniating nucleus pulposus as well as a host of other features, including an audible release feature.

“This is the best model I’ve see,” opines Dr. Robert Gregory Lusk. “As a strong visual learner myself I’ve always appreciated that aspect of the educational process with patients. The moving parts accurately demonstrate how the lumbar spine functions. The disc is particularly impressive as it demonstrates the biomechanics involved with compression, flexion/extension, and rotary forces.”

In the “cervical spine” category, Dr. Fryer offers the Professional CxH model, which is a matching specimen to the Professional Lumbar LxH model (same human spine) portraying  identical cervical size with natural morphology including a two-part intervertebral disc with six degrees of natural motion with a red post-lateral nuclear migration upon manual compression, posterior longitudinal ligament (PLL), anterior longitudinal ligament (ALL) and periosteal fascia (POL) (adjacent to uncovertebral joint).

Many chiropractors choose more than one human spine model for their practice. As a matter of fact, Dynamic Disc Designs offers a Patient Educator Bundle, which combines 7 of the companies most popular models at a drastically-reduced price over what would be paid if they were purchased separately.

Check out the vast selection of human spine models available from ddd. Remember, with the proper education, your patients’ fear will lessen and they’ll develop confidence in you and your profession.


Life Size Vertebra Model – enlarged

Larger Vertebra Model

Enlarged Vertebra Model – using #patientengagement tools

Over the years many people have asked Dynamic Disc Designs Corp. whether we could build a model 2 or 3 times the size for easier viewing. As we understand the need for some to see a larger than realistic model, our company is focused on delivering realistic sized models. Our models are geometrically identical to life size and because we adhere to our strict anatomical core values, there is a simple solution for those customers looking for a larger than life model. It is called a magnifying glass.

The intent is not to be cheeky but practical. There are many links where you can find magnifying glasses. We recommend the 90mm 10x.

Larger Vertebra Model

Having the patient hold the magnifying glass while you point to the posterior annulus and the dynamic nucleus, for example, can be a very effective way to incorporate and educate patients about internal pain generators when looking through our clear bone models. Those with deficiencies in seeing or those that want to have a closer look at the anatomical details of the spine can do it by looking through a magnified lens.

Magnified Clear Bone

So before you consider buying a larger than realistic model from somewhere else, consider a realistic size model by Dynamic Disc Designs Corp. and on the side, find yourself a nice magnifying glass to engage your patients in patient education.