Under state law, police and firefighters who suffer catastrophic injuries while on duty are entitled to health-care benefits.But what counts as a “catastrophic” injury? The state’s top court is slated to rule on that issue this week in a case involving a Vernon Hills police officer who was deemed disabled after he injured his hip slipping on a patch of ice.The case, Village of Vernon Hills v. William J. Heelan, No. 118170, is one of 12 the Illinois Supreme Court is slated to release Thursday.The Public …