Table 3.

Fusion per increased interspace level (N=435)

Interspace level	Count (%)	Fusion rate	95% confidence interval
C2–C3	3 (0.5)	100.0	29.2–100.0
C3–C4	60 (10.0)	93.3	83.8–98.2
C4–C5	77 (12.4)	89.6	80.6–95.4
C5–C6	170 (30.1)	87.1	81.1–91.7
C6–C7	115 (18.9)	75.7	66.8–83.2
C7–T1	10 (1.2)	100.0	69.2–100.0

C2–C7, cervical interspace levels.