It has been known for sometime that his knees are a real concern. In 7 seasons he has played more than 65 games once.
This is why we passed on facilitating to get Bynum. The question still remains why we didn't just trade for Dwight.
Given what we already know about Bynum's knees, this isn't really troubling, IMO. With his condition, he'd honestly be irresponsible to NOT try everything possible to keep his ligaments well-maintained. Anyway, he announced his intention to do this months ago. Of course it's precautionary.
There's really not a question there. It should be obvious what happened. And we should talk about something else.
Saying we should've pushed for Dwight because of Bynum's knee is like saying we should've traded T-Mac for Grant Hill.