Call it a $100 million blow to the head. The Knicks’ season got rocked again last night as Amar’e Stoudemire will have his second knee debridement surgery in four months, putting him out six weeks, ending his regular season and putting him out until the first round of the playoffs at the very earliest. This surgery will be on the right knee — not the left — and should occur by tomorrow. It may be no coincidence it comes after a week in which Stoudemire twice surpassed the 30-minute cap set by the Knicks medical staff to protect his knees. It was a stunning turn of events, potentially threatening their lofty playoff hopes, threatening their chances of holding off the Nets for the Atlantic Division title and coming when their other max star player, Carmelo Anthony, is also battling a mysterious knee injury.