Figure 6
From: Rationale for prostaglandin I2in bone marrow oedema – from theory to application
![Figure 6](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Far2526/MediaObjects/13075_2007_Article_2375_Fig6_HTML.jpg)
The graph shows the different osteonecrosis stages according to Association Research Circulation Osseous (ARCO) classification during follow-up. (a) ARCO stages three months after iloprost application. The distribution was as follows: 56 ARCO 0, 31 ARCO I, 15 ARCO II, 13 ARCO III and two ARCO IV. (b) ARCO stages six months after iloprost application. The distribution was as follows: 65 ARCO 0, 23 ARCO I, 14 ARCO II, 13 ARCO III and two ARCO IV.