Eligibility Criteria -- CSM
| Inclusion Criteria | Exclusion Criteria |
| Cervical cord compression (2 or more levels) from degenerative spondylosis | C2-C7 kyphosis > 5 ˚ (measured on plain film in extension) |
| Clinical myelopathy | Segmental kyphotic deformity (see fig. 1 below) |
| 40 years – 85 years, both genders | Ossification of posterior longitudinal ligament (OPLL) |
| Developmental narrow canal (12 mm – canal diameter) |
| Inclusion | Exclusion |
  |  |
Two cases with sagittal CT reconstructed images are depicted. A line is drawn from the dorsal caudal point of C2 to the dorsal caudal point of C7. If 3 or more levels of disc-osteophyte extend dorsal to the line, then the case has a segmental-cervical kyphotic deformity and the case would be excluded from the study. The C2-C7 Cobb angle is 5 degrees lordosis in both cases.