Adverse events by surgical approach.
| Adverse Events Term | Serious | Relatedness | Severity | Surgical Approach |
| Radiculopathy L5–S1 distribution | Yes | Definitely related | Severe | Posterior |
| Surgery; lami fusion L4/5 and L5/S1 | Yes | Probably related | Severe | Anterior |
| Back pain with sciatica | No | Probably related | Severe | Anterior |
| Swelling | No | Possibly related | Moderate | Anterior |
| Increased numbness | No | Possibly related | Moderate | Anterior |
| Worsening foraminal stenosis | No | Possibly related | Moderate | Anterior |
| Postoperative neuritis | No | Possibly related | Moderate | Anterior |
| Tingling | No | Possibly related | Mild | Anterior |
| Numbness | No | Probably related | Mild | Anterior |
| Pain | No | Possibly related | Moderate | Lateral |
| Increased spondylosis | No | Possibly related | Mild | Lateral |
| Increased spondylolisthes | No | Possibly related | Mild | Lateral |
| Increased back pain | No | Possibly related | Moderate | Lateral |
| Pain | No | Possibly related | Moderate | Lateral |
Note: Adverse events may present from the same patient.
a There were a total of 14 adverse events: 8 (57.1%) in the anterior group, 5 (35.7%) in the lateral group, and 1 (7.1%) in the posterior group.