20. Achievement of optimal clinical outcomes in adult spinal deformity surgery requires prioritizing realignment goals and varies based on pelvic incidence

Abstract

BACKGROUND CONTEXT Many patients are unable to undergo a major adult spinal deformity (ASD) corrective surgery due to deformity severity, age, comorbidities, and overall frailty status. In order to optimize quality of life in patients with ASD there may be alignment ratios to be prioritized across different presentations of spinal shape. PURPOSE To prioritize radiographic alignment ratios for alignment. STUDY DESIGN/SETTING Retrospective review of a single surgeon adult spinal deformity database. PATIENT SAMPLE A total of 165 patients undergoing ASD corrective surgery OUTCOME MEASURES Minimal clinically important difference (MCID) for SRS-22r and Oswestry Disability Index (ODI); proximal junctional kyphosis (PJK). METHODS Included: patients >18yrs undergoing surgery for ASD (scoliosis ≥20°, SVA ≥5cm, PT ≥25°, or TK ≥60°) with full baseline (BL) and 2-year (2Y) radiographic parameters and HRQL scores. Patients were stratified by baseline pelvic incidence: low PI ( RESULTS A total of 165 ASD patients included (56.7±16.3yrs, 80.3% female, 25.8±5.3kg/m2). By approach, anterior: 0.6%, posterior: 91.2%, and combined approach: 8.2%. Average levels fused: 11.3±4.1, operative time: 332 min, estimated blood loss: 1,968 ccs. By baseline PI: 24.3% low PI, 75.7% high PI. (47 patients) of patients met the criteria for BCO, which was evenly distributed among the Roussouly types (p=0.115). For low PI patients, a combination of correcting the PI-LL from 0-25%, SVA 75-100%, and PT 0-25% significantly predicting acquiring the BCO (R2 =0.622, p=0.002). For BCO in high PI patients, a 25-50% correction in PI-LL, SVA minimal, and PT 75-100% (R2 =0.297, p=0.021). Low PI patents who met the three ratios of correction (PI-LL, SVA and PT) had less major complications (11.1% vs 23.1%) compared to other low PI patients. High PI patients who were corrected to the Schwab quartile of ratios underwent less reoperations (6.1% vs 23.3%) and had less PJK occurrence by 2-years postop (20.4% vs 40%), all p CONCLUSIONS Certain ratios of correction of the SRS-Schwab modifiers contribute to improving clinical outcomes and vary by preoperative spinal shape. Prioritization of global realignment relative lumbo-pelvic mismatch depends on the theoretical contour of the individual patient. Importantly, certain subgroups experience the most clinical benefit from the initial percentages of realignment, which may obviate more aggressive corrections on an individual basis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.