Hockey is a game of the unexpected. Nothing, and nobody, exemplifies that more than Dallas Stars forward Mattias Janmark. Janmark sat out the entirety of the 2016-17 season (although, hey, he didn’t miss anything) due to a genetic knee disorder called osteochondritis dissecans.
Osteochondritis dissecans is caused by a small section of the underlying bone in the human knee losing blood flow and bone cells, then beginning to gradually die out. Once it does die, the bone (the subchondral bone, to be exact) cannot support the articular cartilage and the cartilage begins to detach from the bone itself.