How are our bones connected? The body's bones are connected to each other at many spots.
If the bone itself touched the other bone directly, when you moved you would slowly grind them together.
Not only would the pain be excruciating, your bone would eventually disintegrate.
Thankfully, there is specialized that reduces the friction and wear between bones.
This tissue is called cartilage.
When it is damaged, however, by time, mechanical injury or genetic defect, the bone starts to rub against things it shouldn't.
This causes arthritis, a very painful inflammation and swelling at joints.
How does the cartilage get damaged? When you play sports or engage in rigorous physical activity, you start to damage your cartilage.
Your knees experience particularly severe strain.
Imagine the force that your knee experiences when you kick a ball, or worse, trip and land on your leg.
This continuous pressure is what your body is built to absorb and deal with.
But at the same time, we used to live a lot shorter.
If you were going to die at age 40, it wouldn't matter how healthy your knee is.
In fact, just one traumatic experience can by itself tear the cartilage.
Types of damage There are two primary types of damage.
Partial damage, which does not go down to the bone, and full damage which does.
How your body responds to the damage is very different depending whether or not the bone is exposed.
If you experience full damage, blood seeps into the wound, carrying with it cell populations such as mesenchymal stem cells.
These cells can grow and regenerate the wound.
While the damage itself is greater, that your body does try to heal itself is very important.
Unfortunately, the tissue that it does form does not perform as well as the old, and will often degenerate with time.
Partial tearing or damage of the cartilage, however, has a limited healing response.
This damage very often contributes to premature arthritis.
Medical Intervention Arthroscopy is one of the more common medical procedures in the USA for knee pain and consists of various mechanical interventions.
A doctor inserts instruments into your knees and may conduct various operations.
One common procedure is to simply removed pieces that are damaged and causing pain.
This is called debridment.
Another method is to wash the knee with water.
Combined with debridement, this procedure may reduce pain significantly and help prevent arthritis.
Other options include microfracture and transplantation Transplantation consists of taking live tissue and implanting it into the damaged area.
The tissue used may be derived from the patient himself - and so called autologus - or taken from another patient - allogeneic.
The exact properties of the transplant tissue is an area of intense medical exploration.
A serious problem in transplantation is tissue failure.
While you might be able to insert into my knee perfectly healthy cartilage, it takes cellular ingrowth and other biochemical events to be properly maintained.
Even the most successful transplants suffer from some degree of degeneration and early failure.
Microfracture and similar procedures attempt to use the body to heal itself.
We know that certain types of cartilage wounds do in fact heal to some degree.
What if we artificially drilled holes into the tissue and let the blood flow to the damaged areas? While seemingly counterproductive, such drilling does indeed improve patients.
Transplantation In the worst case scenario, you may need a knee or hip replacement.
While a very common procedure with excellent results, the surgery is traumatic and takes months to recover from properly.
While most implants perform well, eventual failure is an issue along with degradation and wear.
Most implants tend not to elicit severe immunological response as they are made from metals, ceramics and polymers.
Future Treatments A future venue for research is inserting matrixes into the damaged area.
A matrix, in addition to being a hit film, is a specially designed microstructure that allows for cellular ingrowth.
Inserting a matrix may help cells grow and repair the damaged tissue.
Also, the matrix could be seeded with materials or even cells that will promote proper regrowth.