Osteoarthritis (OA) is a wear and tear disease of articular cartilage. It arises as a result of the lack of ability of cartilage to keep up with excessive breakdown. It's a common disorder affecting more than 20 million Americans.
So far, the treatment of osteoarthritis is mostly symptomatic. Various medicines, called non-steroidal anti-inflammatory drugs (NSAIDS), exercises, physical therapy, and injections are used to provide palliative relief. Ultimately, patients will go on to have knee replacement surgery.
More recently, attempts at cartilage repair through the use of autologous (a patient's own) mesenchymal stem cells (MSCs) has shown promise.
Noted initially in animal models such as goats, sheep, and rabbits, the reparative benefit of autologous stem cells has also been reported anecdotally in humans.
There are multiple descriptions regarding technique. The most common is to centrifuge bone marrow or fat to concentrate the stem cells and then inject them into the joint.
While the simplicity of this approach is appealing, it is probably not effective.
MSCs migrate to areas of new injury. If the surrounding environment is conducive to their survival, they will undergo multiplication and differentiation and populate any framework that is provided in order to begin the reparative process.
That being said, all of the above factors need to be in place in order to achieve the desired outcome.
There must be an area of new injury that attracts the MSCs; there must be a favorable environment with growth factors that stimulate MSC differentiation and multiplication; and finally, there must be a suitable framework that provides sanctuary for the MSCs in a hostile environment.
A proper MSC procedure will require the expert use of various anesthetics. Anesthetic needs to be administered in the form of both local soft tissue as well as regional block. Knowledge of anatomy as well as the use of diagnostic ultrasound to localize nerves is important. Also, knowledge of the pharmacokinetics of the various anesthetics is important in order to avoid toxicity.
Finally, if arthroscopy is needed in order to better visualize the area or to deliver the acute injury at a specific site, the use of intra-articular anesthesia is critical.
General anesthesia is not required.
Obviously, there is some discomfort associated with the administration of anesthetics. After all, how can a needle stick be rendered absolutely painless? However, when properly done for OA, a MSC procedure will be somewhat uncomfortable but should not be overwhelmingly painful.
Ironically, most of the discomfort occurs after the procedure because the nature of a regenerative procedure requires the aid of a robust inflammatory response to deliver healing.
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