Table 2 Comparison of TAD and Shortening between traditional group and pre-sliding group

TAD value(cm)

M(Q1,Q3)

2.5(1.8, 3.4)

1.3(0.9, 1.6)

<0.001

Shortening distance (1 day, mm)

M(Q1,Q3)

1.5(0.2, 3.5)

0.5(0.1, 2.2)

0.07

Shortening distance (1 month, mm)

M(Q1,Q3)

6.9(2.5, 10.3)

2.5(1.2, 3.6)

<0.001

Shortening distance (3 months, mm)

M(Q1,Q3)

7.8(3.4, 11.6)

3.0(1.5, 4.4)

<0.001

Shortening distance (6 months, mm)

M(Q1,Q3)

7.8(3.7, 15.2)

3.2(1.7, 4.4)

<0.001

Shortening distance (1 year, mm)

M(Q1,Q3)

7.8(3.7, 15.2)

3.2(1.7, 4.5)

<0.001

Shortening grading (1 year)

Mild(<5 mm)

30(55.6%)

46(82.2%)

<0.001

Moderate(5–10 mm)

10(18.5%)

5(8.9%)

Severe(>10 mm)

14(25.9%)

5(8.9%)