Arthritic changes are very common. They are often related to a person’s pain with neck pain as one of the highest ranked common causes of disability. In this specific research article 1, the authors looked at the micro-details of neck synovial joints. With osteoarthritis known to be related to neck pain, they were looking to reveal higher anatomical detail and they were also curious about whether men or women have more of these problems.
With both neck and back pain being multifactorial (which may include both psychological and social aspects) degenerative changes within the synovial joints play a significant structural role with the development of spondylosis. This is a general term to describe a disorder of the musculoskeletal system with an emphasis on joint space narrowing, intervertebral disc height loss and frequent formation of bony spurs.
The architecture of the cervical facet joints is quite well known with most of the current knowledge around the smooth (or lack of smoothness) hyaline cartilage to allow the joint to receive and distribute loads in an efficient manner. However, there has not been much quantitative data revealing the anatomy under the hyaline cartilage designated as the subchondral bone. This bone under the cartilage (sub, meaning below and chondral, meaning cartilage) has been of recent interest as there exist nerves in this area that can cause pain. This is thought to be similar to the basivertebral nerve of the vertebral body. The innervation of the facet, however, has ascending fibres travelling through the posterior primary division which can be seen in this Medial Branch Dynamic Disc Model.
Previous research has shown that the thickness of the hyaline cartilage is .4mm in women and .5mm in men with the subchondral bone making up approximately 5% of the total cartilage thickness. It is also known that with increasing age the cartilage starts to flake off (called fibrillation) and researchers also coin the stripping of cartilage from the bone, denudation. This means being nude. A joint surface within a covering. Other terms used to describe the break down of the hyaline cartilage is erosion, fissuring and deformation. All in all, the terminology all mean that the hyaline is thinning.
How did they do it?
These researchers looked at 72 recently deceased people and examined their joints. They used microscopes to look closely at the facet joints to help understand the pathogenesis of the arthritic changes.
When they observed the osteocartilaginous junction, the morphological changes included: flaking, splitting, eburnation, fissuring, blood vessel invasion and osteophytes. They looked at the length of the cartilage, the hyaline cartilage thickness, the calcified cartilage thickness and the subchondral bone thickness.They found that males tended to have more severe degenerative changes described by flaking and severe fissures in the facet cartilage. Click To Tweet
Points of Key Interest
- this was a study that looked at 1132 unique cervical spine facets from 72 humans
- males were found to have more degenerative changes of the osteocartilaginous junction
- the thickness of the calcified cartilage and subchondral bone increased with age whereas the hyaline cartilage decreased
- the osteocartilaginous junction is particularly important in the pathogenesis of osteoarthritis in the cervical spine facet joints
At Dynamic Disc Designs, we work to bring research to the practitioner so when there is a teaching moment, Professionals are ready to explain pain triggers as they relate to a patients symptoms and movements. Empowering people about their own anatomy helps in the crafting of customized treatment plans for each unique pain patient. Explore our dynamic models and help a patient understand their arthritic changes and what that means to them.