Postoperative clinical data comparison of the patients by laminoplasty group.
| Postoperative Clinical Data | MP Group | LP Group | P Value |
| JOA score | |||
| Before surgery | 9.1 ± 7.9 | 8.7 ± 7.2 | 0.84 |
| 6 mo after surgery | 12.6 ± 2.2 | 12.7 ± 2.4 | 0.87 |
| 12 mo after surgery | 13.8 ± 3.1 | 13.6 ± 2.8 | 0.64 |
| IR (%) | 59.5 ± 9.2 | 59.0 ± 8.9 | 0.23 |
| VAS | |||
| Before surgery | 5.3 ± 2.6 | 5.2 ± 2.7 | 0.75 |
| 6 mo after surgery | 2.5 ± 1.6 | 3.8 ± 1.6 | <0.01 |
| 12 mo after surgery | 2.1 ± 1.5 | 2.7 ± 1.6 | 0.15 |
| C2–C7 Cobb angle, degree | |||
| Before surgery | 10.2 ± 2.8 | 10.8 ± 2.6 | 0.65 |
| 6 mo after surgery | 11.4 ± 2.8 | 10.6 ± 2.7 | 0.05 |
| 12 mo after surgery | 10.7 ± 2.3 | 9.2 ± 2.4 | <0.01 |
| Loss of lordosis (final follow-up) | 0.7 ± 1.1 | 1.4 ± 1.2 | <0.01 |
| Postoperative complications, n (%) | |||
| Persistent axial neck pain | 2 (9.1) | 7 (15.2) | 0.75 |
| C5 nerve root palsy | 0 (0.0) | 1 (2.2) | 0.68 |
| CSF leakage | 1 (4.5) | 4 (8.7) | 0.91 |
Note: Data presented as mean ± SD except where otherwise noted. Boldface indicates statistically significant findings.
CSF, cerebrospinal fluid; IR, improvement rate; JOA, Japanese Orthopaedic Association; LP Group, traditional open-door laminoplasty-treated patients; MP Group, haplo-paraspinal-muscle-preserving laminoplasty-treated patients; VAS, visual analog scale.