I have two that could take the cake:
1- I was 13, and i was pitching. 8 pitches into the first inning I threw a fastball , and about halfway through the throw, the muscles in my arm Ripped off a piece of my elbow. Its called an Avulsion Fracture and it was a freak injury. The surgeon said it was because "the muscles in the arm were to strong for the bone" and i was "too explosive for my age". Had re-constructive surgery 2 days later, fixed as good as new. Also, I went into a coma from the knockout drugs, but woke after 5 extra hours.
2- About 2 months ago, i was in the cage taking some swings (i am also 1st baseman) at my travel team practice and on my last swing, my foot jammed into the turf, and my leg rolled foward and i got a full Dislocation of my left kneecap. The kneecap was stuck on the outside of my leg, and i was rolling on the floor, yelling and cussing. An ambulance had to be called, and 5 shots of Morphine and 2 shots of Valium later, they could still hardly move me. The Doctor at the hospital than told me he was gona straighten my leg, i said okay (i didnt know what he meant). So one doc grabs my ankle and yanks it, and the other about punches my kneecap back into place. Again, i started cussing. The final damage was a severe strain of the MCL and bruised cartilage. No surgury required, but they said that it hurt as much as it did because the MCL didnt tear, and it was just pulled to its fullest extent. They also said that they are suprised i didnt pass out and go into shock. Ive been in physical therapy for 35 days, and was just cleared by the Knee Specialist to play in the season, which starts next week. Now i have to get full clearance from the trainer and i am all set. BTW, i threw my first bullpen today since the injury. The docs and trainers are amazed at my recovery. (So am I, I usually am a very slow healer).