Osteonecrosis is defined on ankle and foot radiographs as increased radiographic density, relative to the adjacent osseous structures, essentially meaning that there has been interruption of the vascular supply to the bone causing bone death. Although this sounds bad, in this study it appears that the radiographic density will normalize in about half of the cases. In terms of your recovery it will be important to see if the osteonecrosis determined in your follow up x-ray revascularizes or if there is a resultant collapse of the talar dome. If the talar dome collapses there will be a higher likely hood that you will experience some form of post traumatic arthritis due to permanent changes in the bone and subsequent joint surfaces.