My son dislocated his left shoulder a few years ago. Since then, he's dislocated it three times. He did have surgery after the second time, but a few months later, it happened again. Why can't the doctor fix it properly?

Shoulders are joints that take on a heavy load from us. They have to be able to turn and pivot, and the must be able to bear a significant amount of weight. They get jarred from time to time as we unexpectedly catch something that is falling, for example, and we often stretch them more than they should be. As a result, once they've been hurt, it may be difficult to get them back to their original condition.

You don't say what type of surgery your son had, whether it was the traditional open surgery with a large incision or the smaller arthroscopic surgery with smaller incisions, but both may not always work 100 percent. According to a recent study, a lot depends on your son's age when he first dislocated his shoulder, if it is his dominant shoulder, and his sex. Many of the failed shoulder surgeries do seem to be among men.