Table 2.

Histologic Scoring Scale for Fusion

Fusion	Score
Union of TPs by mature bone; complete bridge	10
Union of TPs by immature bone and cartilage; complete bridge	9
Union of TPs by cartilage with little fibrocartilage	8
Partial union with more bone (> 75%) than cartilage and fibrocartilage	7
Partial union with more bone (56% – 75%) than other tissues (i.e., cartilage, fibrocartilage and fibrous tissue)	6
Partial bridge; ∼equal amounts of bone (45% – 55%) and other tissues (i.e., cartilage, fibrocartilage and fibrous tissue)	5
Minimal bridge with less bone (25% – 44%) than other tissue (i.e., cartilage, fibrocartilage and fibrous tissue)	4
Minimal bone (<25%) with predominantly other tissue (i.e., fibrocartilage, predominantly fibrous tissue)	3
Little new bone with predominantly fibrous tissue	2
Fibrous tissue only between TP; full (across the defect)	1