Complex sentence: His career came to an end one game too early when he suffered a right knee injury in Round 21 2007, it occurred when he changed direction to tackle an opponment resulting with his knee bending and twisting the wrong way.
Split into simpler sentences: His career came to an end one game too early when he suffered a right knee injury in Round 21 2007. It occurred when he changed direction to tackle an opponment resulting with his knee bending and twisting the wrong way.