While the article ( available at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5629a2.htm?s_cid=mm5629a2_e ), focuses on brain injuries from sports participation, the authors (see table 1) estimate that, between 2001-2005, there were over 380,000 emergency room visits for youth basketball-related injuries. That's more than football, more than bicycling, more than baseball, soccer, or any other sport listed.
If you look at all ages, basketball is still the sport associated with the most emergency room visits (over 600,000 during that same time period).
For the dubious distinction of causing brain injuries (concussions and worse), youth basketball ranks 3rd, behind bicycles and football, two sports where the use of helmets is mandated.
Don't get me wrong, I consider basketball to be the best sport on the planet and would encourage all young athletes to learn, practice, and enjoy it.
But the next time you think about going out to play, keep in mind that it is a high-speed, contact sport that can send you to the hospital so you should take every opportunity to rehabilitate, train, and use protective equipment to reduce your chance of being the one seen in the local emergency room.