Actually, MSC therapies specifically for cartilaginous repair are probably outside of the clinical trial stage now. I studied about 'em two years ago, and only one company was entering the market with it. AFAIK, the sucess rate is still below 15%, but it couldn't hurt, because there are generally no side effects if the area they want to regenerate is small. . More info: http://en.wikipedia.org/wiki/Stem_cell_transplantation_for_articular_cartilage_repair
That is unfortunate, because agreeing with the drummer probably means you disagree with the bass player, and he's burly as fuck.