Table 2: Values are Disc Heights Given as the Difference in Standard Deviations from an Age and Gender Adjusted Normal Population. Mean ±SD at Baseline and 9-Years Follow-Up in Fused and Non-Fused Patients and the Mean Difference (95% CI) Between Groups are Given

Level Lumbar Fusion (n = 23)1 No Lumbar Fusion (n=25)1 Adjusted2 Mean Difference Between Groups
Baseline 9-Years Baseline 9-Years
L2-L3 (non-fused level) -0.65±1.23 -1.13±1.39 -0.29±0.88 -0.65±1.29 0.14 (-0.51 to 0.79)
L3-L4 (non-fused level) -0.54±1.33 -1.32±1.25* 0.18±1.02 -0.45±1.17** 0.36 (-0.27 to 0.98)
L4-L5 (fused level) -0.88±1.33 -1.61±1.70** -0.81±1.30 -1.35±1.42** 0.03 (-0.57 to 0.63)
L5-S1 (fused level) -1.19±1.62 -1.55±1.47 -1.08±1.02 -1.38±1.08 0.20 (-0.38 to 0.78)

1 At level L5-S1: lumbar fusion n = 19 and no lumbar fusion n= 21.
2 Adjusted for previous discectomy and baseline values.
* p<0.05
** p<0.01.