Deterioration After adult spinal deformity (ASD) surgery, global coronal alignment (GCA) decline may be linked to poorer outcomes. The effect of fusion length and upper instrumented vertebra (UIV) selection patients with this problem is unknown. The goal of the study was to compare the results of long sacropelvic fusion with upper-thoracic (UT) UIV with lower-thoracic (LT) UIV in patients with a GCA of less than 1 cm. A retrospective analysis of ASD patients was conducted using prospective multicenter database data. The index operations used instrumented fusion from the sacropelvis to the thoracic spine. Global coronal degeneration was defined as a change in GCA of 1 cm or more from preoperative to 2-year follow-up.

About 560 (64%) of the 875 theoretically eligible patients had complete 2-year follow-up data, with 144 (25.7%) showing worse GCA at 2-year postoperative follow-up (35.4% of UT patients vs. 64.6% of LT patients). Although both UT and LT patients had similar percentages of problems (208 total, including 53 reoperations, 77 serious complications, and 78 mild complications), the percentage of reoperated patients was higher in the UT group (35.3% versus 18.3%, p = 0.023). Rod fracture (13.7% vs 2.2%, p = 0.006) and pseudarthrosis (7.8% vs 1.1%, p = 0.006) exhibited greater reoperation rates in UT patients, but not proximal junctional kyphosis (9.8% vs 8.6%, p = 0.810).


UT UIV was related to worse 2-year HRQL than LT UIV in ASD individuals with worse 2-year GCA following long sacropelvic fusion. This fusion could indicate that residual global coronal malalignment is clinically less tolerated in ASD patients with lengthier fusion to the proximal thoracic spine. These findings could help with surgical planning and patient counseling.