One powerful reason why some spinal healing takes longer than anticipated.
Healing in most body tissues requires clotting and inflammation
Healing from any injury requires inflammation. And almost everywhere in the body, the first part of the inflammatory process requires some sort of clotting.
Clotting is where blood cells and other tissue form into a kind of mesh that allows the repair process to get started.
Our body makes a special protein compound called Fibrin to get that healing/inflammation party started. Fibrin is an important ingredient in the mesh that will form the clot.
There are areas in the body where clotting is not allowed
Here’s the funny thing…There are a few areas of the body where clotting isn’t allowed, and one of those places is inside the joint structure of a synovial joint.
Synovial joints are some of the most common joints in our body, like the knees, shoulders, hips, wrists, ankles, and even our toes and fingers.
What makes them synovial?
They have a special liquid inside and the whole joint is wrapped in a special ligament called a capsular ligament. Synovial joints have the ability to move a lot thanks to this design.
Synovial joints and fibrinolysis?
So back to the fun fact at hand, and why it may matter to you.
This area inside synovial joints undergoes something called fibrinolysis, which stops the formation of the normal healing matrix. Fluid can accumulate in the joint, but clotting won’t happen, as long as there’s no break in the integrity of the joint.
This doesn’t mean these joint spaces cannot heal at all. It just means that their path to healing is different than the usual wound healing we might have seen at the surface of the skin.
It’s a path to healing that’s slower than other body areas with a normal clotting response and blood supply.
The lesson of the ACL and PCL?
Why does this matter? Particularly for the spine? We have probably all heard of a tearing of an ACL or PCL (two big ligaments) of the knee.
These kinds of tears will end in surgeries if the joint cannot be stabilized through exercise, and there are two reasons why: because these are ligaments, and the fact that they are ligaments inside of a synovial joint.
You can think of ligaments as strong, tensile, and fluid-filled ropes that connect bones to bones…But that fluid is mostly water, not blood.
In fact, ligaments do not have a direct blood supply, the normal path to wound healing, which means they heal really slowly.
But some ligaments also have something else going on.
Because the ACL and PCL are inside the knee, they have to deal with the reality of fibrinoloysis stopping clotting from happening in the tissue environment around them.
They are inside a synovial joint. Any ligaments inside of a synovial joint or encircling a synovial joint are going to deal with two different paths to wound healing because they are ligaments firstly, and secondly, the tissue matrix nearby or around them will not experience clotting.
The synovial joints of the spine?
The facet (z-joints) of the spine are synovial joints.
Now, let’s move into an area that’s less commonly known than the knee for most people: the spine.
Some spinal injuries that lead to vertebral misalignment, joint breakdown, and nervous system irritation can also cause ligament injuries.
Some of these ligaments will interact with the interior surface of a synovial joint, specifically the capsule ligaments of the spine, and a few specialty ligaments at the top of the neck.
These ligaments that are part of a lining of a synovial joint are called inter-articular ligaments.
These ligaments are part of the z-joints of the spine, and z is short for zygapophyseal. These are the joints that connect the back end (sometimes called the “posterior elements”) of the spinal bones to together, and where most of the motion in the spine actually happens.
Now remember ligaments take a long time to heal and their healing may be incomplete in the best of circumstances. Fibrinolysis inside that capsular joint area may stop or slow the initial inflammation phase.*
Because as we learned above, the normal healing matrix doesn’t form in synovial joints.
These few facts are important for understanding why some people may take a long time to heal and become stable in their chiropractic spinal care, while others do not.
And why some people may rely on routine, gentle adjustments of the spine in order to maintain their function over their lifetime
Not every spine has the same soft tissue injury around their misalignment.
Some have experienced more stress to the capsular ligaments of the z-joints than others. We are accustomed to talking about disc degeneration, and how this can affect “arthritis” in the neck or another area of the spine, but few know about or consider the differences in the soft-tissue recovery of the ligaments of the spine, especially around those synovial z-joints.
This is something to keep in mind, when you’re comparing chiropractic care stories.
Some patients simply feel like they can function more easily with regular release of these irritated/damaged spinal areas and choose long term maintenance to help support their alignment.
And this may be one important reason why.
* Anatomists and other science-minded probably want to read the following clarification. First, I understand the capsular ligaments appear in two layers, and only the inner layer makes up the synovial surface of the joint. The action of fibrinolysis would be relevant for this inner layer. Second, since ligaments are said to not have a direct blood supply, it could be argued that the question of clotting may or may not be important to all to the ligaments of all joints in general. However, several texts on the healing of synovial joints, particularly the knee, hip, and shoulder identify the unique healing challenges of intra-articular joints (ligaments in and around synovial surfaces) due to the process of fibrinolysis, so it stands to reason that the synovial joints of the spine may experience a different healing path and associated challenges than the joints contained by the margins of the vertebral bodies or the vertebral disc surfaces which are not surrounded or bordered by tissues that limit fibrinogen activity.