- Diebo, Bassel;
- Alsoof, Daniel;
- Lafage, Renaud;
- Daher, Mohammad;
- Balmaceno-Criss, Mariah;
- Passias, Peter;
- Ames, Christopher;
- Shaffrey, Christopher;
- Burton, Douglas;
- Deviren, Vedat;
- Line, Breton;
- Soroceanu, Alex;
- Hamilton, David;
- Klineberg, Eric;
- Mundis, Gregory;
- Kim, Han;
- Gum, Jeffrey;
- Smith, Justin;
- Uribe, Juan;
- Kebaish, Khaled;
- Gupta, Munish;
- Nunley, Pierce;
- Eastlack, Robert;
- Hostin, Richard;
- Protopsaltis, Themistocles;
- Lenke, Lawrence;
- Hart, Robert;
- Schwab, Frank;
- Bess, Shay;
- Lafage, Virginie;
- Daniels, Alan
Background: The objective of this study was to evaluate if imbalance influences complication rates, radiological outcomes, and patient-reported outcomes (PROMs) following adult spinal deformity (ASD) surgery. Methods: ASD patients with baseline and 2-year radiographic and PROMs were included. Patients were grouped according to whether they answered yes or no to a recent history of pre-operative loss of balance. The groups were propensity-matched by age, pelvic incidence-lumbar lordosis (PI-LL), and surgical invasiveness score. Results: In total, 212 patients were examined (106 in each group). Patients with gait imbalance had worse baseline PROM measures, including Oswestry disability index (45.2 vs. 36.6), SF-36 mental component score (44 vs. 51.8), and SF-36 physical component score (p < 0.001 for all). After 2 years, patients with gait imbalance had less pelvic tilt correction (-1.2 vs. -3.6°, p = 0.039) for a comparable PI-LL correction (-11.9 vs. -15.1°, p = 0.144). Gait imbalance patients had higher rates of radiographic proximal junctional kyphosis (PJK) (26.4% vs. 14.2%) and implant-related complications (47.2% vs. 34.0%). After controlling for age, baseline sagittal parameters, PI-LL correction, and comorbidities, patients with imbalance had 2.2-times-increased odds of PJK after 2 years. Conclusions: Patients with a self-reported loss of balance/unsteady gait have significantly worse PROMs and higher risk of PJK.