So far we have looked at the idea of using microfractures surgery principles and techniques as a starting point for ideas to cause potential height increase. In the first post, we looked at where the origin of the idea came from. The 2nd post was to go explain what is the knee microfracture surgery is, which is a arthroscopy procedure.

This last post is to see whether we can from an integration of the ideas behind the micrafracture surgery can come up with something real.

Analysis And Interpretation:

The reason why I thought we might be able to use the ideas of microfracture surgery to develop an height increase minimal surgical method was because of how minimally invasive the approach was, and how easily cartilage can be formed, at least for articular cartilage repair or decreased degeneration and damage. Microfractures have been mentioned extensively within this community and this medical procedure, specifically on the knee and leg region seemed to have some similar and maybe even applicable ideas.

The main issue that the Wikipedia source seems to reveal is that the cartilage that is formed from the bone marrow stem cell clots is that it is fibrocartilage, not hyaline cartilage. From the Wikipedia article on cartilage, we find out that there is apparently 3 types of cartilage. (I had stated before that there was only 2, so I was wrong about that point.) From the article…

“Cartilage is composed of specialized cells called chondroblasts that produce a large amount of extracellular matrix composed of collagen fibers, abundant ground substance rich in proteoglycan, and elastin fibers. Cartilage is classified in three types, elastic cartilage, hyaline cartilage and fibrocartilage, which differ in the relative amounts of these three main components. Chondroblasts that get caught in the matrix are called chondrocytes. They lie in spaces called lacunae with up to eight chondrocytes per lacuna.”

So they say that the difference between the hyaline cartilage and the fibrocartilage is the relative amounts of the 3 main components…

1. collagen fibers
2. ground substance composed highly of proteoglycans
3. elastin fibers.

I remember when I was doing research that the chondrocytes do leave a type of waste, that the waste is two main components that make up the cartilage extracellular matrix, the collagen type II, and the proteoglycans.

Continued….

“Unlike other connective tissues, cartilage does not contain blood vessels. The chondrocytes are supplied by diffusion, helped by the pumping action generated by compression of the articular cartilage or flexion of the elastic cartilage. Thus, compared to other connective tissues, cartilage grows and repairs more slowly.”

We do remember that the perichondrium, which is a layer of cells that surrounds cartilage that is in DEVELOPING bones. This makes me wonder whether after the bones have stopped growing, is the perichondrium still there, at least in the articular cartilage layer? From it’s Wiki page…

“The perichondrium is a layer of dense irregular connective tissue which surrounds the cartilage of developing bone. It consists of two separate layers: an outer fibrous layer and inner chondrogenic layer. The fibrous layer contains fibroblasts, which produce collagenous fibers. The chondrogenic layer remains undifferentiated and can form chondroblasts or chondrocytes. Perichondrium can be found around the perimeter of elastic cartilage and hyaline cartilage. Fibrocartilage and articular cartilage both lack perichondrium

Perichondrium is a type of Irregular Collagenous Ordinary Connective Tissue, and also functions in the growth and repair of cartilage

Once vascularized, the perichondrium becomes the periosteum.”

So when we combine the two wiki articles together, we get a better image of how the development of cartilage to bone and cartilage and bone separately work. Cartilage seems to always have some tendency to turn into bone. The cartilage does not contain blood vessels, but get their food or energy by the process of diffusion. In the developing bone at least, when there is still an epiphyseal plate to talk about, the growth plate cartilage has a surrounding perichondrium. There is two layers, an outer fibrous layer (which I would guess has the function of structure and protection) and an inner chondrogenic layer (for proliferation and acts as a source for new chondrocyte formation). The chondrogenic layer doesn’t get differentiated but can change into either the chondorcytes or chondroblasts.

One of the most most important phrases in the wiki article on perichondrium is this “Once vascularized, the perichondrium becomes the periosteum.” I remember from other studies on the periosteum that the periosteum around the long bones also have two layers like their predecessor, the perichondrium. The outer layer of the periosteum is something I haven’t looked at extensively but I did write a post looking at the possible idea for using the inner layer of the periosteum as a way to increase height before.

From the Wikipedia article on cartilage continued….

Repair

Cartilage has limited repair capabilities: Because chondrocytes are bound in lacunae, they cannot migrate to damaged areas. Therefore cartilage damage is difficult to heal. Also, because hyaline cartilage does not have a blood supply, the deposition of new matrix is slow. Damaged hyaline cartilage is usually replaced by fibrocartilage scar tissue. Over the last years, surgeons and scientists have elaborated a series of cartilage repair procedures that help to postpone the need for joint replacement.

Bioengineering techniques are being developed to generate new cartilage, using a cellular “scaffolding” material and cultured cells to grow artificial cartilage.

This shows the same issues that is talked about in the microfracture surgery issue, which is that hyaline cartilage is replaced with fibrocartilage.

From source (McGrawHill)…

Hyaline Cartilage

The type of protein fiber embedded within the matrix of cartilage determines the cartilage type.  In hyaline cartilage protein fibers are large and predominantly collagen.  The optical density of these fibers is the same as the ground substance surrounding them and as a result, they are not visible within the extracellular matrix.  Hyaline cartilage subsequently appears as a very uniform, glossy type tissue with evenly dispersed chondrocytes in lacunae.  Typically, perichondreum is found around hyaline cartilage.

• Chondroblasts would be found as flattened, elongate cells between the perichondreum and cartilage.

Elastic Cartilage

Elastic cartilage has a preponderance of dark-staining elastic fibers embedded in ground substance.  These fibers are clearly visible and this trait is the single, best identifier to be used for differentiating elastic cartilage from hyaline.  Perichondreum is also typically found around elastic cartilage.  Elastic cartilage is found in the pharyngotympanic(eusatachian) tubes, epiglottis, and ear lobes where needs dictate supportive tissues possess elasticity.

Fibrocartilage

Fibrocartilage(fibrous) is a type of cartilage that contains fine collagen fibers arranged in layered arrays.  In contrast to the very uniform appearance of hyaline cartilage, fibrocartilage possesses a more open or spongey architecture with gaps between lacunae and collagen fiber bundles.  It is this open spongey structure that makes fibrocartilage a good shock-absorbing material in the pubic symphysis and intervertebral disks.  It can appear quite different in these two locales.  Most textbooks show images of fibrocartilage from the intervertebral disks where it is very open and loose.  In the pubic symphysis, it can be much tighter in construction, appearing like a dense connective tissue with lacunae.  

What we are seeing for the difference between the fibrocartilage and the hyaline cartilage is that the collagen fibers are arranged differently. The hyaline cartilage is a very uniform, glossy type tissue. The fibrocartilage is different because it has a more open and spongey architecture of the gaps between the lacunae and collagen fiber bundles. The hyaline cartilage in contrast has a uniform, evenly dispersed chondrocytes in lacunae.

Implications for Height Increase:

If we decided to try to drill microfractures into the long bone ends, what would happen is that the stem cells that seeps out would be disorganized and not be distributed in uniform which would be what determines hyaline cartilage from the other types. Fibrocartilage formation from the clotting process would be a given. It might be possible that through adding a type of scaffold that the cartilage type can be changed to be hyaline. What could work is that if a series of microfractures in a specific distribution design is created from drills on the side of the epiphysis to completely go around the bone in a closed path. This means that after a few days, the path of drilled microfractures would fill up with stem cells which will eventually turn into fibrocartilage. The fibrocartilage will not be that strong, but before they calcify into bone from vascularization, it would be possible to drill another set of microfractures around the same path to fill up the remaining bone bridges. The idea that we are using is to get a punctured hole to the subchondral, subcortical bone layer so that the stem cells inside would come out and turn into cartilage.