When the Dallas Stars announced that Mattias Janmark was going to miss the next 5-6 months with a knee injury suffered in practice, my first thought was he'd torn his ACL. That's the most common hockey knee injury that takes that time frame for recovery, and it's notorious for occurring in low-or-no contact scenarios.
But, for better or worse, that wasn't the case with Janmark. He has an injury/underlying condition called osteochondritis dissecans, a name that made me go "huh?" the first time it was reported by Jim Nill. So as is in my nature, I went digging on the internet for more information.