Overall (n = 87/85)

55 ± 16

42 ± 19

0.0001

Age > 59 (n = 32/32)

53 ± 15

36 ± 20

0.001

Age ≤ 59 (n = 55/53)

56 ± 16

45 ± 18

0.05

Previous Surgery (n = 31/31)

60 ± 17

48 ± 20

0.05

No Previous Surgery (n = 56/54)

52 ± 14

38 ± 18

0.001

Tobacco Use (n = 29/29)

57 ± 16

46 ± 16

0.05

No Tobacco Use (n = 58/56)

54 ± 16

40 ± 21

0.001

BMI > 30 (n = 41/40)

51 ± 14

39 ± 18

0.01

BMI ≤ 30 (n = 46/45)

58 ± 17

45 ± 20

0.01

L5-S1 Included in Construct (n = 45/44)

54 ± 16

44 ± 18

0.05

L5-S1 not Included in Construct (n = 42/41)

56 ± 16

40 ± 21

0.001

Posterior Approach (n = 65/63)

55 ± 15

41 ± 19

0.0001

Anterior Approach (n = 22/22)

55 ± 18

44 ± 21

0.001

Pseudarthrosis Repair (n = 8/8)

56 ± 13

51 ± 13

> 0.05