| Type I (Figure 5) | No intramedullary sclerosis |
| Fracture line with sharp margins and no widening |
| Minimal cortical hypertrophy |
| Minimal evidence of periosteal reaction to chronic stress |
| Type II, delayed | Fracture line that involves both cortices with associated periosteal bone union (Figure 6) |
| Widened fracture line with adjacent radiolucency related to bone resorption |
| Evidence of intramedullary sclerosis |
| Type III, nonunion | Wide fracture line |
| Periosteal new bone and radiolucency |
| Complete obliteration of the medullary canal at the fracture site by sclerotic bone |