Surgical characteristics of 1040 adults who underwent surgery for spinal deformity.
| Characteristic | Early Start (N = 771) | Late Start (N = 269) | P Value (Early vs Late Start) | ||
| n (%) | Mean ± SD | n (%) | Mean ± SD | ||
| Mirza invasiveness index | 21 ± 8.2 | 19.8 ± 8.8 | 0.04 | ||
| Number of levels fused | 10.4 ± 4.0 | 9.6 ± 4.4 | 0.01 | ||
| Operative time (h) | 6.9 ± 3.7 | 6.5 ± 3.0 | 0.12 | ||
| 3-Column osteotomy | 88 (11) | 37 (14) | 0.85 | ||
| Posterior column osteotomy | 284 (37) | 125 (46) | 0.31 | ||
| TLIF | 192 (25) | 96 (36) | 0.04 | ||
| ALIF | 26 (3.4) | 8 (3.0) | 0.48 | ||
| Multirod (>2) configuration | 451 (58) | 167 (62) | 0.19 | ||
| Estimated blood loss (mL) | 1721 ± 1596 | 1466 ± 1297 | 0.16 | ||
| Length of hospital stay (d) | 6.5 ± 3.8 | 6.8 ± 3.9 | 0.20 | ||
ALIF, anterior lumbar interbody fusion; TLIF, transforaminal lumbar interbody fusion.