TABLE III.

Criteria Used to Define Radiographic Fracture Union on Plain Radiographs^*

Radiographic Criteria Used to Define Fracture Union	Number of Articles (N = 120)
1. Bridging of fracture by callus/bone/trabeculae or osseous bone	63 (53%)
2. Bridging of fracture by callus, trabeculae, or bone	32 (27%)
3. Obliteration of fracture line/cortical continuity	22 (18%)
4. Bridging of fracture at 2 cortices	7 (6%)
5. Bridging of fracture at 1 cortex	4 (3%)
6. Absence of fracture displacement†	4 (3%)
7. Absence of hardware failure/loosening	3 (2.5%)
8. Absence of osteonecrosis	2 (1.7%)
9. Calcification of callus	2 (1.7%)
10. Bridging of fracture at 4 cortices	1 (1%)
11. Presence of callus	1 (1%)

^*The radiographic criteria were grouped into eleven similar categories and were arranged in order of most to least common use.

^†Assessed at one to three months following treatment.