Boned (25 player) is an achievement in the 25man version of Icecrown Citadel
Same strat as 10man version.
To get this achievment the "Bone Spikes" that impale players must be targeted and destroyed in under 8 seconds.
The raid leader must ensure the DPS understand this. This simply requires DPS, especially ranged DPS to react quickly to every Bone Spike and burn it down quick, then return to damaging the boss.
It is possible, that with enough geared DPS, a group may automatically get the achievment.