by John From mama mia in the comments: "so in my weird need to figure this out, were these pins just placed above and below the bone, thru flesh/muscle tissue, just to keep the bones still while in the cast?" Yup, that's the basic picture! Owen fractured his humerus right at the joint in what the kids today call a supracondylar fracture. From what I understand, it was a vertical crack right between the points where the humerus meets the radius and ulna. The pins were inserted through his flesh into the bone on either side of the fracture, presumably to keep the bone immobilized and to help the two pieces fuse together again. Fortunately, that's all in the past now. Owen's cast is off and his right arm is rehabilitating quickly!