What you see here is my knee before and after surgery a week ago.  The top two pictures show the miniscus and some material caught in the knee joint itself.  The operation trimmed the torn material and removed it.  It also removed most of the meaterial floating around in the joint.  At the bottom left is the picture of the joint once the material was removed.  It's relatively round and has nice clean edges, but you can see that there are still things floating around in there.