Open fractures have been classified by Gustilo as follows, with higher numbers indicating more severe injuries:
| Gustilo Classification | ||
| I | Low energy, wound less than 1 cm | |
| II | Wound greater than 1 cm with moderate soft tissue damage | |
| III | High energy wound greater than 1 cm with extensive soft tissue damage | |
| IIIA | Adequate soft tissue cover | |
| IIIB | Inadequate soft tissue cover | |
| IIIC | Associated with arterial injury | |