Matthew Matava, head physician for the NFL's St. Louis Rams and team physician for the NHL's St. Louis Blues, says there is a general rule when it comes to the number of injections: No more than three to four in a year.
"I suppose there are always exceptions to any rule," says Matava. "These are guidelines. They're sort of based on expert opinion as opposed to any hard and fast scientific data consisting of randomized, controlled trials.
"Certainly if you start getting into six to eight shots into a joint, that's where it becomes problematic.'' The biggest concern, says Matava: cartilage damage, or rupturing a tendon.
