Preoperativeand postoperativecomparison of various spinal canal dimensions among different levels.
| L2-3 (n=19) | L3-4 (n=36) | L4-5 (n=36) | L5-S1 (n=25) | ||
|---|---|---|---|---|---|
| Interfacet distance (mm) | Pre-op | 8.0 | 7.5 | 9.0 | 12.9 |
| Post-op | 16.0 | 16.9 | 18.4 | 18.9 | |
| Difference | 8.0 | 9.3 | 9.4 | 6.0 | |
| Ratio increase (%) | 115.8 | 137.0 | 133.6 | 61.6 | |
| AP canal diameter (mm) | Pre-op | 9.8 | 9.1 | 8.9 | 9.8 |
| Post-op | 14.8 | 15.0 | 15.4 | 15.5 | |
| Difference | 5.0 | 5.8 | 6.5 | 5.7 | |
| Ratio increase (%) | 55.3 | 67.7 | 78.0 | 63.6 | |
| Right lateral recess depth (mm) | Pre-op | 1.6 | 1.6 | 1.5 | 1.7 |
| Post-op | 3.9 | 4.0 | 3.9 | 3.9 | |
| Difference | 2.3 | 2.3 | 2.3 | 2.1 | |
| Ratio increase (%) | 172.2 | 165.0 | 172.8 | 133.0 | |
| Left lateral recess depth (mm) | Pre-op | 1.7 | 1.6 | 1.6 | 1.9 |
| Post-op | 4.2 | 3.8 | 3.9 | 3.5 | |
| Difference | 2.4 | 2.2 | 2.2 | 1.5 | |
| Ratio increase (%) | 160.9 | 157.8 | 172.5 | 94.4 | |
| Right lateral recess angle (°) | Pre-op | 18.7 | 16.4 | 16.8 | 19.7 |
| Post-op | 39.9 | 41.9 | 39.0 | 34.4 | |
| Difference | 21.1 | 25.5 | 22.1 | 14.7 | |
| Ratio increase (%) | 123.3 | 183.2 | 163.8 | 80.5 | |
| Left lateral recess angle (°) | Pre-op | 18.9 | 17.4 | 15.3 | 20.8 |
| Post-op | 37.5 | 39.7 | 36.6 | 36.5 | |
| Difference | 18.5 | 22.2 | 21.3 | 15.6 | |
| Ratio increase (%) | 112.6 | 152.8 | 159.7 | 87.8 | |
| Cross-sectional canal area (mm2) | Pre-op | 77.4 | 72.13 | 78.1 | 101.1 |
| Post-op | 193.2 | 196.3 | 189.5 | 200.7 | |
| Difference | 115.8 | 124.2 | 111.4 | 99.6 | |
| Ratio increase (%) | 165.6 | 190.6 | 168.5 | 115.5 |
Values represented are mean values.