Skip to main content

Table 3 L4 and L5 spinous process parameters at baseline 1 week and 1 year after surgery

From: Bone resorption during the first year after implantation of a single-segment dynamic interspinous stabilization device and its risk factors

  Bone resorption (n = 29) Nobone resorption (n = 15) p
L4 spinous process
Height
Baseline 83.0 ± 9.7 81.8 ± 8.7 .698
1 week 77.5 ± 9.3 76.6 ± 11.0 .776
1 year 71.2 ± 11.2 69.4 ± 11.9 .635
Significant resorptiona 5 (17.2) 0 (0.0) .149
Length
Baseline 54.6 ± 7.4 57.2 ± 7.4 .279
1 week 50.5 ± 8.3 51.7 ± 8.0 .654
1 year 40.4 ± 10.1 46.7 ± 8.1 .042*
Significant resorptiona 17 (58.6) 0 (0.0) .001*
Thickness
Baseline 13.2 ± 2.7 13.1 ± 2.2 .871
1 week 12.4 ± 2.6 12.1 ± 2.7 .725
1 year 11.1 ± 2.5 11.5 ± 2.7 .604
Significant resorptiona 7 (24.1) 0 (0.0) .077
L5 spinous process
Height
Baseline 73.9 ± 11.2 70.3 ± 11.8 .319
1 week 67.6 ± 11.3 64.3 ± 10.9 .358
1 year 56.0 ± 11.5 57.4 ± 10.4 .699
Significant resorptiona 11 (37.9) 0 (0.0) .008*
Length
Baseline 42.5 ± 10.6 46.1 ± 7.6 .244
1 week 37.3 ± 10.2 41.4 ± 6.6 .167
1 year 25.6 ± 6.9 37.2 ± 7.3 <.001*
Significant resorptiona 21 (72.4) 0 (0.0) <.001*
Thickness
Baseline 12.6 ± 2.9 11.4 ± 2.7 .182
1 week 11.9 ± 2.8 10.3 ± 2.8 .094
1 year 10.0 ± 2.1 9.7 ± 2.9 .704
Significant resorptiona 12 (41.4) 0 (0.0) .003*
  1. Data are presented as mean ± standard deviation or counts (percentage).
  2. *p < .05, indicates a significant difference between groups.
  3. aBone resorption rate = (value at 1 week postoperative – value at 1 year postoperative)/value at 1 year postoperative × 100. Significant resorption defined as a bone resorption rate > 20%.