Pacioretty slammed Boychuck into the boards during the opening five minutes of the game and Boychuck collapsed to the ice.
After several minutes of being treated by trainers from both teams, Boychuck was placed on a stretcher and taken to a local hospital for observation. Boston General Manager Peter Chiarelli said Boychuck had movement in all of his extremities after the incident.
Pacioretty, who received a minor penalty for his hit on Boychuck, put a backhander past Tuukka Rask with 2:18 left in the second for the final goal.
Carey Price stopped 32-of-33 shots for the Canadiens, who won their fourth in a row. Rask made 25 saves.