What's wrong with Bryce Harper's Knee?

I apologize for the delay between blog posts.  Things were very hectic at the end of the spring semester and the beginning of the summer.  If you are a baseball fan, then you know Bryce Harper, the young star outfielder for the Washington Nationals, injured his knee over a month ago when he collided with the outfield wall.  Haper missed a few games, played in a few, and then recently went on the disabled list.  So, what injury did Harper sustain?

Harper was diagnosed with bursitiis, which was confirmed today by Dr. Andrews.  Bursitis is inflammation of a bursa.  A bursa is a fluid filled sac that is found near many of our joints, such as the knee, ankle, elbow, and shoulder.  In the picture above, you can see that there are four bursa around the knee.  It is likely that Harper injured his prepatellar bursa when he ran into the wall.  The prepatellar bursa is located directly above the patella.  It is very superficial and easily injured during collisions.  When a bursa sac is irritated, it can cause a lot of swelling and inflammation around a joint.  This can make movements of the knee painful and difficult.  It generally does not cause swelling within the joint, because the bursa is located outside the joint.  The best course of treatment for bursitis is rest and anti-inflammatory medication.  However, this option is not often chosen during the middle of a competitive season.  Because Harper's knee was not responding, they had to place him on the disabled list.  I will discuss the treatment he received for this injury from Dr. Andrews in the next blog post.