The primary diagnosis of study patients for indications for H laminectomy (N = 85).
| Primary Diagnosis | n |
| Degenerative laminectomy without fusion | 36 |
| Degenerative laminectomy with fusion | 27 |
| Trauma | 8 |
| Revision laminectomy with fusion | 6 |
| Metastatic tumor | 4 |
| Epidural abscess | 2 |
| Revision laminectomy without fusion | 1 |
| Cord untethering | 1 |