128. Evolution of adult cervical deformity surgery clinical and radiographic outcomes based on a multicenter prospective study: Are behaviors and outcomes changing with experience?

With an aging population and increased prevalence of cervical deformity, corrective surgery is increasingly utilized as a treatment option. The goal of this study is to examine whether surgical advancements and expansion of knowledge over the years have improved or changed outcomes and the way we approach cervical deformity surgery. To investigate if outcomes or surgical approach have changed over time. Retrospective cohort study of a prospective adult cervical deformity (ACD) database. This study included 119 ACD patients. Complications after ACD surgery within 2 years, HRQL (NDI, mJOA, EQ5D) ACD patients (≥18 years) with complete baseline and 2-year HRQL and radiographic data were included. Descriptive analysis included demographics, radiographic, and surgical details. Patients were grouped into Group I (2013-2014) and Group II (2015-2017) by DOS. Univariate, and multivariate analysis determined differences in surgical, radiographic, and clinical outcomes between groups. A total of 119 cervical deformity patients met inclusion criteria (61.3years, 67%F, BMI: 29kg/m2, CCI: 0.96±1.3). Radiographically at baseline, patients presented with: PT: 18.8± 11.3; PI: 53.0±11.1; PI-LL: -.45±17.7; SVA:-4.34±66.8, TS-CL: 38.1 ±21.4; cSVA: 45.2±25.6. Surgically, 51.3% had osteotomies, 47.1% had a posterior approach, 34.5% combined approach, 18.5% anterior approach, with 7.6± 3.8 levels fused and EBL of 824 mL. Group I consisted of 72 patients, and Group II consisted of 47. Group II had a higher CCI (1.3 vs.72), more cerebrovascular disease (6% vs 0%, both p<0.05), and no difference in age, frailty, deformity, or cervical rigidity. Group II had a lower surgical invasiveness (9 vs 11, p<0.05), trended towards a lower EBL (677 vs 921, p=.124) and shorter LOS (5.1 vs 7.9, p=.065), with no difference in levels fused, approach, reoperations, DJK development, or HRQLs (p>0.05). Controlling for baseline deformity and age, patients in Group II underwent fewer three-column osteotomies.17[.04-.8], (p<0.05). Patients undergoing three-column osteotomies had a deformity primarily in the CT region (48%), followed by C (23%) and T (19%) with a similar distribution between Groups (p>0.05). Additionally, controlling for levels fused and three-column osteotomies, Group II experienced fewer minor complications.3[.09-.96], (p<0.05). At 2 years, Group II had fewer patients with a moderate/high Ames horizontal modifier (71.7% vs 88.2%), fewer patients who were overcorrected in PT (4.3% vs 18.1%) and fewer patients with a +, or ++ deformity in PT SRS-Schwab (9.1% vs 39.5%). In a site-specific subanalysis, controlling for age, CCI, baseline deformity, and levels fused, Group II experienced fewer adverse events than Group I.138[.027-.713], (p=.018). Despite operating on a higher risk cohort with more comorbidity, outcomes have remained consistent, indicating improvements in care. Surgically, there has been a reduction in the number of three-column osteotomies performed, suboptimal realignments, and fewer complications and adverse events. This suggests a better understanding of minimizing the risk of cervical deformity surgery with fewer invasive techniques. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]