Comparison of VAS low back pain scores between Group 1 and Group 2 participants (N = 610).
| Variable | Pain on VAS 0–10, Mean ± SD | ||||||
| Before procedure | 3 d after procedure | 1 mo after procedure | 3 mo after procedure | 6 mo after procedure | 9 mo after procedure | 1 y after procedure | |
| Group 1 | 7.59 ± 0.95 | 5.57 ± 1.11 | 4.17 ± 1.24 | 3.42 ± 1.32 | 2.86 ± 1.22 | 2.52 ± 1.08 | 2.34 ± 1.01 |
| Group 2 | 7.67 ± 0.93 | 5.71 ± 1.03 | 4.36 ± 1.16 | 3.61 ± 1.32 | 3.14 ± 1.27 | 2.76 ± 1.20 | 2.57 ± 1.16 |
| P | 0.289 | 0.115 | 0.050 | 0.073 | 0.005 | 0.012 | 0.010 |
Abbreviations: TPED, transforaminal percutaneous endoscopic discectomy; VAS, visual analog scale.
Note: Group 1 comprises patients who underwent TPED during the first 3 years of the study. Group 2 comprises patients who underwent TPED during the last 3 years of the study.