Scar Tissue From Mild to Wild
by Dr. Michael Moon, Pathologist
Editor’s Note: This is a companion article/podcast to The Why’s and How’s of Scar Tissue that you can read here.
Collagen and Elastin
In the normal organism, normal tissues, you have a combination of Collagen and Elastin that allow movement and also stability. Collagen more for stability, Elastin more for malleability or movement. When you have injury, you end up with fibrosis, the result of fibroblasts, laying down Collagen to repair. But you do not have replacement of the elastic fibers that you had previously. This differs in different people to a greater or lesser degree.
Collagen Builds Fibroblasts
And what we’re talking about then is basically scar formation. When you have the Collagen laid down by the fibroblast, you’re forming, “a scar.” You can see the results of that on skin. It also takes place anywhere in the body after injury. Different individuals have different capabilities in terms of this repair. When we see it on skin, we may refer to it as a scar.
Scar Tissue at 10x Magnification
A scar is the marking that remains after tissue damaged from a cut, burn, or other wound has healed. The most familiar scars appear on the surface of the skin, though they also can develop on tissues located inside the body.
Scar formation is a natural process. Scars result from replacement tissue being somewhat structurally and functionally different than the original tissue that was injured.
Produced by fibroblasts, scar tissue is predominantly composed of fibrous connective tissue made of collagen. It is typically thicker, denser, and paler than surrounding tissues. The poor elasticity of scar tissue can limit movement in areas of the body that were extensively damaged. The lack of oil glands in the inferior tissue is sometimes associated with itchiness or irritation. (compliments of NIKON Microscopy)
Hypertrophic Scar (Keloid)
If an individual has an exaggerated ability to do this, to lay down Collagen, to lay down a reparative fibrosis or scar, you can get what we refer to as hypertrophic scars or Keloids. And these can be seen on the scan. And you can tell if an individual is more likely to form a hypertrophic scar or Keloid. When it’s beneath the surface, say from surgery, you cannot necessarily recognize this as easily. However, they all have some of the same effects, as I alluded to earlier.
They do not contain Elastin fibers. So you have some decrease in the resilience, the malleability or the ability to move the area, particularly when we’re talking about a joint. That can be of some concern.
As pathologists we can tell the difference between those two microscopically. Other than being able to do that, that’s really not of importance, because they have the same effect. If you have a very intuitive physician that notices a scar on the surface of the patient, they could be tipped off, “Oh, this person forms Keloids. They are more likely to have an exaggerated fibrotic response, so this is something to look out for.
Keloids and Keloid Removal
Once you’ve seen it on a person, you know it’s a Keloid. And it’s a difficult problem more cosmetically a lot of times for individuals because you try to remove … the Keloid then is an aesthetic, more so than a normal scar. And so if you try to remove the Keloid, then they form another Keloid, because it’s their tendency to form this exaggerated fibrotic response.
Identifying Hypertrophic Scars and Keloids
You could see it microscopically by taking biopsies and looking at the individual cells. You examine the amount of Collagen that is present and the orientation of that Collagen microscopically. This works well particularly if you have a frame of reference, for example, the skin surface, with respect to the skin surface how that Collagen is being laid down.
But you can also see it clinically by symptomatology. How stiff is the region? How stiff is the joint, or how movable it is? How movable versus stiff immovable the joint is.
You can get an idea as to how much that fibrosis or scarring is progressing, to what degree it’s progressing. And to me, it’s a clinical judgment and something that clinicians can do because of their experience with patients.
The X10 Meta-Blog
We call it a “Meta-Blog.” We step back and give you a broad perspective on all aspects of knee health as with this article on Scar Tissue from Mild to Wild.
In this one-of-a-kind blog we gather together great thinkers, doers, and writers. All our work is related to Knee Surgery, Recovery, Preparation, Care, Success and Failure. Meet physical therapists, coaches, surgeons, patients, and as many smart people as we can gather to create useful articles for you. This is for you if you have a surgery upcoming, or in the rear-view mirror. Or maybe you just want to take care of your knees to avoid surgery. Executive Editor: PJ Ewing
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