Table 1.
The anteroposterior diameter of dural sac and spinal cord on each position.
| Level | CSM patients |
Asymptomatic subjects |
|
|---|---|---|---|
| Flexion (mm) | Extension (mm) | Neutral on MRI (mm) | |
| The anteroposterior diameter of dural sac | |||
| C2/C3 | 10.5 ± 1.3 | 10.4 ± 1.5 | 12.4 ± 1.6 |
| C3/C4 | 8.9 ± 1.4 | 8.6 ± 1.6 | 10.6 ± 1.4 |
| C4/C5 | 8.7 ± 1.6 | 7.7 ± 1.8 | 10.3 ± 1.5 |
| C5/C6 | 8.4 ± 1.6 | 7.1 ± 1.5 | 9.9 ± 1.5 |
| C6/C7 | 9.0 ± 1.4 | 7.8 ± 1.5 | 10.3 ± 1.5 |
| C7/T1 | 10.3 ± 1.3 | 9.6 ± 1.3 | 11.6 ± 1.4 |
| The anteroposterior diameter of spinal cord | |||
| C2/C3 | 6.5 ± 0.9 | 6.3 ± 0.9 | 7.7 ± 0.8 |
| C3/C4 | 5.7 ± 1.2 | 5.3 ± 1.2 | 6.9 ± 0.9 |
| C4/C5 | 5.2 ± 1.1 | 4.5 ± 1.4 | 6.6 ± 1.0 |
| C5/C6 | 4.8 ± 0.9 | 4.1 ± 1.0 | 6.3 ± 0.9 |
| C6/C7 | 5.0 ± 0.8 | 4.7 ± 1.0 | 6.2 ± 0.9 |
| C7/T1 | 5.2 ± 0.8 | 4.9 ± 0.7 | 6.1 ± 0.7 |
Values given are mean ± standard deviation (SD) unless otherwise specified.
CSM indicates cervical spondylotic myelopathy.