Stem cells are undifferentiated cells with the potential to differentiate into specialized cell types. There are two main types of such cells: Embryonic and adult or somatic stem cells. There are ethical considerations for the use of embryonic stem cells. Adult stem cells, on the other hand, occur naturally in our bodies in “niches,” and are called upon for repair/regeneration in response to wound, degeneration etc. While stem cells are being actively researched around the world, there are still quite a few unanswered questions. Among them is whether these natural repair machines in our bodies can somehow be harnessed for therapeutic purposes. Scientists are making a concerted effort to achieve this goal. A few clinical trials are taking place in the US and several others worldwide. An area of focus in stem cell therapy is to repair damage done by osteoarthritis with the aim to either postpone or avoid major surgeries thereby improving the quality of a patient’s life.
In such procedures, the doctor or clinical staff extracts bone marrow from the pelvic bone, which is the richest source of marrow in humans. It contains a mixture of hematogenous (precursor cells for various cell types of the blood) stem cells, mesenchymal (which can give rise to cartilage and bone cells) stem cells, platelet-rich plasma, growth factors and several anti-inflammatory molecules. The extract is subjected to centrifugation to separate the cell types. This results in a concentrate, termed the “bone marrow concentrate or BMC,” which is enriched in mesenchymal stem cells, along with growth and anti-inflammatory factors. BMC is then introduced into the affected knee area under ultrasound guidance. Since the cells are from our own bodies, the possibility of a rejection is minimal.
The entire procedure takes about 4 hours and is performed in compliance with FDA regulations. After discharge, the patient is advised to use crutches for 48 hours. If the patient’s job is not labor-intensive, he/she is allowed to return to work after 5 days. However, to return to physically demanding jobs, a person has to allow 4-6 weeks for complete recovery. There are usually restrictions on smoking and alcohol consumption and physical rehabilitation might be necessary. Most patients tolerate the procedure rather well.
Preliminary results from such stem-cell therapies have been encouraging. There are several factors influencing the outcome of these procedures. Following stem cell therapy, young patients, with a body mass index of less than 30, with early to intermediate arthritis, report less pain and increased function in their knees. In such patients, it appears that the procedure is not only therapeutic, but prevents further damage to the knees. Patients with advanced arthritis, obesity or who are on medication that could interfere with the therapy, are not ideal candidates for this kind of treatment. Therefore, these procedures are not for everyone, at least not at the present time. However, stem cell therapy as an option for common knee problems should not be ruled out and be actively considered.
Current perspectives in stem cell research for knee cartilage repair, Stem Cells Cloning, 2014. 7:1-14.
Dr. Mitchell Sheinkop, Orthopedic stem cell resource (personal communication); www.sheinkopmd.com