Complex sentence: Allison suffered a hand injury in a game against the Montreal Canadiens, and had to have surgery on his hand, which sidelined him for the remainder of the season, he scored 17 goals and had 60 points for the Maple Leafs.
Split into simpler sentences: Allison suffered a hand injury in a game against the Montreal Canadiens, and had to have surgery on his hand, which sidelined him for the remainder of the season. In the 66 games he played in before the injury, he scored 17 goals and had 60 points for the Maple Leafs.