Table 2. Length of stay (hours) by type of procedure and number of levels treated.

Levels	Stand-alone				Pseudoarthrosis				Circumferential (360°)
	N	Median	Range		N	Median	Range		N	Median	Range
All levels	143	26.0	6–336		37	27.0	8–240		84	28.0	12–123
1 level	55	24.0	9–144		18	25.5	12–60		28	24.0	23–123
2 levels	57	27.0	6–156		15	29.0	8–240		23	24.0	18.5–96.0
3 levels	26	28.5	22–336		3	12.0	12–48		30	29.0	12–96
4 levels	3	26.0	23–49		1	24.0	24–24		3	61.5	42–81