Definitions of union or non-union, where stated amongst included papers
| Authors | Definition (union/non-union) | Definition |
| Bhatnagar et al 199247 | Non-union | A fracture that shows no evidence of progressive healing at 6 months after injury. |
| Nicholas and McCoy 199548 | Union | The absence of pain and motion at the fracture site and good callus formation on X-rays. |
| Pukljak 199751 | Union | Successful weightbearing after removal of external fixation or plaster cast. |
| Kuklo et al 200819 | Non-union | Failure of bridging callus on anteroposterior and lateral radiographs at 12 months after injury. |
| Keeling et al 200818 | Union | Osseous consolidation evident on radiographs and minimal pain on palpation at fracture site. |