Karen, my son who is now 16, was told when he turned 14 (also 5’6") that he would not grow any more, he was very upset as growth and bone age had always been fine, then all of a sudden we were told his bones were fused. I asked about growth hormones etc and was told they would be of no use, guess what he grew another 3" inches! However not to worry you, but one thing that has happened, is that he has developed a curvature of the spine (hunch) which has been diagnosed as  Scheuermann’s disease (which can be caused through endocrine disorders) and now has lost a little height from this.