Table 1.
Patient demographic data
| MiTLIF group | OTLIF group | |
|---|---|---|
| No. of patients | 25 | 27 |
| Mean age (years) | 54.8 ± 10.9 | 56.2 ± 13.6 |
| Gender (M/F) (% male) | 13/12 (52.0) | 15/12 (55.6) |
| Previous diagnoses [no. (%) of patients] | ||
| Lumbar disc herniation | 9 (36.0) | 11 (40.7) |
| Lumbar spinal stenosis | 16 (64.0) | 16 (59.3) |
| Duration after previous surgery (months) | 83.5 ± 17.4 | 90.2 ± 21.6 |
| Revision diagnoses [no. (%) of patients] | ||
| Recurrent disc herniation | 7 (28.0) | 8 (29.6) |
| Lumbar canal stenosis | 10 (40.0) | 9 (33.3) |
| Segmental instability | 5 (20.0) | 7 (25.9) |
| Spondylolisthesis (<grade 2) | 3 (12.0) | 3 (11.1) |
| Level of fusion [no. (%) of patients] | ||
| L3–L4 | 2 (8.0) | 2 (7.4) |
| L4–L5 | 11 (44.0) | 11 (40.7) |
| L5–S1 | 9 (36.0) | 10 (37.0) |
| Two-level fusion | 3 (12.0) | 4 (14.9) |
* P < 0.05, ** P < 0.01