The Orthopaedic Research Society held its annual meeting earlier this month in New Orleans, and the display of scientific advances and the dream of their applications to the clinical world certainly were exciting. On display were the results of experiments integrating engineering and biological research on the cells, tissues and organs of the musculoskeletal system. Among all these statistics and conclusions is a keen expectation that the chronic pain so many suffer due to degenerative arthritis and ligament and tendon injuries may one day be alleviated by the implantation of new cells and a tincture of growth factor.
Here is just a sampling of what is going on in research labs throughout the world:
1. Microbubbles, bubbles on a miniature level almost unimaginable, are being used to modify scaffolds, which are in turn foundations of a sort for the growth of new cartilage engineered from stem cells, for transplantation into the knees of injured athletes (and non-athletes). The bubbles eventually dissolve, leaving pores which allow the diffusion molecules essential to the growth of strong tissue.
2. Muscle-derived stem cells can be induced to express bone growth factors, allowing for the healing of large bone defects, such as fractures.
3. Magnetically labeled stem cells can be precisely delivered via external magnetic targeting, allowing accelerated bone formation by using fewer stem cells.
4. Embryonic stem cells can be used for tendinitis repair, avoiding the scarring seen with surgical repair of rotator cuff injuries, for example.
5. The cholesterol-lowering drug, lovastatin (Mevacor), can be injected into an area of bone fracture, accelerating the repair of fractured bone.
6. Nanotubes can be injected as a liquid, which then go on to solidify into a viscous gel, allowing for an increase in the adhesion of stem cells and the subsequent more robust growth of new bone or cartilage.
Of course, whenever one speaks of stem cells and growth of new tissue, one must also be concerned about the risk of tumors. But researchers have discovered biochemicals which can be added to the "broth" in which stem cells grow, inhibiting tumorogenic behavior.
Alas, the examples of breakthroughs cited above are the result of work done on animal models, but human studies are around the corner. And I truly believe there will come the day when we will not have to stand by and watch cartilage degenerate to the point where a person needs an artificial hip or artificial knee-assuming they are even healthy enough for such surgery. There will come a day when we will be able to inject into a joint new cells which will grow new cartilage or new tendons or new ligaments.
In the meantime, those of us with aches and pains still have a heating pad and Tylenol.