Table 2 Cases of postoperative disc herniation among the study groups
Total cohort | Mini-open partial laminectomy | Minimally invasive laminotomy | p value* | |
|---|---|---|---|---|
Postoperative disc herniation (overall) | 21 of 563 (3.7%) | 19 of 326 (5.8%) | 2 of 237 (0.8%) | 0.002 |
Timing of disc herniation (onset of radicular symptoms) (days) | ||||
42 ± 20 (19 to 84) | 39 ± 16 (19 to 71) | 80 ± 6 (76 to 84) | 0.023 | |
Postoperative disc herniation after a single-level operation | ||||
Overall | 13 of 485 (2.7%) | 11 of 287 (3.8%) | 2 of 198 (1.0%) | 0.049 |
L1–L2 | 0 | 0 | 0 | |
L2–L3 | 0 | 0 | 0 | |
L3–L4 | 1 | 1 | 0 | |
L4–L5 | 10 | 8 | 2 | |
L5–S1 | 2 | 2 | 0 | |
Postoperative disc herniation after a multi-level operation | ||||
Overall | 8 of 78 (10.2%) | 8 of 39 (20.5%) | 0 of 39 (0.0%) | 0.003 |
Two levels | 7 | 7 | 0 | |
Three levels | 1 | 1 | 0 | |
Four levels | 0 | 0 | 0 | |