Table 3.
Bare window width analysis according to age group
| Age group [n] | L2–L3 | L3–L4 | L4–L5 | 
|---|---|---|---|
| < 40 years [n = 173] | 1.32 ± 0.35 | 1.20 ± 0.33 | 0.46 ± 0.41 | 
| 40–60 years [n = 97] | 1.43 ± 0.39 | 1.33 ± 0.38 | 0.74 ± 0.47 | 
| > 60 years [n = 37] | 1.63 ± 0.45 | 1.49 ± 0.50 | 1.04 ± 0.59 | 
| P value | < 0.001 | < 0.001 | < 0.001 | 
All values are mean ± SD [cm]; n, number of cases in each age group
Difference of Bare window width at L2–3: < 40 versus 40–60 (p = 0.03); 40–60 versus > 60 (p = 0.007); < 40 versus > 60 (p = < 0.001)
Difference of Bare window width at L3–4: < 40 versus 40–60 (p = 0.007); 40–60 versus > 60 (p = 0.032); < 40 versus > 60 (p = < 0.001)
Difference of Bare window width at L4-5: < 40 versus 40–60 (p = < 0.001); 40–60 versus > 60 (p = 0.001); < 40 versus > 60 (p = < 0.001)