I went to the Wicked backstage tour two weeks ago and Tony Galde (a swing in Wicked for years and one of the creators of the tour) said his first Broadway job (at 18 or 19) was in Starlight Express and he broke every finger on his right had a one time or another and during one show he broke his left arm. He fell and when he got up, his forearm was just hanging down at this very weird angle. He just skated offstage and was taken to the hospital.
I dont think WICKED has had any major injuries aside from SJB and Idina but those were freak accidents (Idina's could happen to any actor who makes an exit via a elevator on the floor) But the dancing they do in Ozdust is pretty extensive in terms of flinging their bodies in awkward positions so who knows how many are injured. It always seems like the swings are on so maybe it is tough
"Life in theater is give and take...but you need to be ready to give more then you take..."