Are Chondrocytes or Stem Cells better for Cartilage Repair?
Fascinating study out this week that compares chondrocytes (cartilage cells) and mesenchymal stem cells (MSC’s) derived from bone marrow in their ability to repair cartilage based on key metrics. The winner? Stem Cells derived from bone marrow (MSC’s). In particular, the MSC’s produced more chemicals capable of repair and still had the potential to repair cartilage cells through differentiation. This study fits with an earlier clinical trial that was a head to head comparison between the knee ACI surgical technique (Autologous Chrondrocyte Implantation, better known as a cartilage patch) and placing bone marrow stem cells (MSC’s) surgically into a cartilage defect. Based on a few differences, the authors concluded that the MSC’s worked better. I often explain to my patients that the difference between a cartilage cell and and a bone marrow derived stem cell can be seen in terms of a construction site metaphor. Chondrocytes are like bricks (in this case the bricks that build the cartilage repair). The problem is that if you dump a load of bricks near a house, they won’t assemble themselves. Stem cells are also the bricks, but bricks that are capable of excreting certain signals that bring the brick mason and general contractor to the repair. This function of MSC’s is called a paracrine effect-they secrete certain chemicals to help orchestrate the repair job. This is something that cartilage cells (chondrocytes) are incapable of doing. Can adipose derived mesenchymal stem cells do this in a joint? Not according to this study (however the study involved blind implantation of cells similar to someone injecting stem cells without imaging guidance, something that we have said in earlier posts is not a good idea. The study also relied on stem cells derived from other animals and not the cells from the same animal). The upshot? Stem cells from bone marrow are better than cartilage cells in repairing cartilage defects. While ACI is a surgery that has helped people, there may be a much better way of surgically repairing cartilage. There may even be a way to improve pain and function without the need for surgery, simply by injecting stem cells into a specific spot using imaging guidance.Learn about Regenexx procedures for knee conditions.