Table 2.
Operative Data of the IS and the S2AI Groups.
| IS (n = 17) | S2AI (n = 46) | P | |
|---|---|---|---|
| No. of operated levels, mean ± SD | 7.5 ± 1.9 | 7.8 ± 2.9 | .68 |
| Uppermost instrumented vertebra, n (%) | .83 | ||
| T9 and above | 0 (0.0) | 3 (6.5) | |
| T10 | 7 (41.2) | 12 (26.1) | |
| T11 | 5 (29.4) | 14 (30.4) | |
| T12 | 1 (5.9) | 3 (6.5) | |
| L1 and below | 4 (23.5) | 14 (30.4) | |
| Staged operations, n (%) | .67 | ||
| 3 stages | 0 (0.0) | 4 (8.7) | |
| 2 stages | 7 (41.2) | 17 (37.0) | |
| 1 stage | 10 (58.8) | 25 (54.3) | |
| Total operative time (minutes), mean ± SD | 733.2 ± 261.1 | 652.0 ± 252.8 | .27 |
| Total EBL (mL), mean ± SD | 2557.6 ± 1572.2 | 2195.8 ± 1548.0 | .42 |
| L5-S1 interbody fusion, n (%) | 9 (52.9) | 31 (67.4) | .63 |
| ALIF, n (%) | 3 (33.3) | 21 (67.7) | .12 |
| PLIF or TLIF, n (%) | 6 (66.7) | 10 (32.3) | |
| Cement vertebroplasty at UIV and/or UIV+1, n (%) | 7 (41.2) | 19 (41.3) | >.99 |
| Smith-Peterson osteotomy, n (%) | 12 (70.6) | 41 (89.1) | .12 |
| Pedicle subtraction osteotomy, n (%) | 5 (29.4) | 6 (13.0) | .15 |
| Received BMP-2, n (%) | 7 (41.2) | 26 (56.5) | .36 |
| Mean dosage of BMP-2 (mg), mean ± SD | 8.5 ± 11.8 | 13.8 ± 14.1 | .17 |
| Total length of stay (days), mean ± SD | 10.9 ± 6.7 | 10.0 ± 7.9 | .65 |
| Total length of ICU stay (days), mean ± SD | 2.6 ± 3.2 | 3.0 ± 4.6 | .74 |
Abbreviations: IS, iliac screw; S2AI, S2-alar-iliac; UIV, uppermost instrumented vertebra; EBL, estimated blood loss; ALIF, anterior lumbar interbody fusion; PLIF, posterior lumbar interbody fusion; TLIF, transforaminal lumbar interbody fusion; UIV+1, the supra-adjacent level of UIV; BMP-2, bone morphogenetic protein–2; ICU, intensive care unit.