Evolution of Adult Cervical Deformity Surgery Clinical and Radiographic Outcomes Based on a Multicenter Prospective Study: Are Behaviors and Outcomes Changing with Experience?

Overview

abstract

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Assess changes in outcomes and surgical approaches for adult cervical deformity (ACD) surgery over time. SUMMARY OF BACKGROUND DATA: As the population ages and prevalence of cervical deformity increases, corrective surgery has been increasingly seen as a viable treatment. Dramatic surgical advancements and expansion of knowledge on this procedure have transpired over years, but the impact on cervical deformity surgery is unknown. METHODS: ACD patients (≥18 yrs) with complete baseline and up to two-year HRQL and radiographic data were included. Descriptive analysis included demographics, radiographic, and surgical details. Patients were grouped into Early(2013-2014) and Late(2015-2017) by DOS. Univariate and multivariable regression analyses were used to assess differences in surgical, radiographic, and clinical outcomes over time. RESULTS: 119 cervical deformity patients met inclusion criteria. Early group consisted of 72 patients, and Late group consisted of 47. Late group had a higher CCI (1.3 vs. 0.72), more cerebrovascular disease (6% vs. 0%, both P<0.05), and no difference in age, frailty, deformity, or cervical rigidity. Controlling for baseline deformity, and age, Late group underwent fewer three-column osteotomies (OR=0.18, 95% CI:0.06-0.76, P=0.014). At last follow-up, Late group had less patients with: a moderate/high Ames horizontal modifier (71.7% vs. 88.2%), and overcorrection in PT (4.3% vs. 18.1%, both P<0.05). Controlling for baseline deformity, age, levels fused, and three-column osteotomies, Late group experienced fewer adverse events (OR =0.15, 95% CI: 0.28-0.8, P=0.03), and neurological complications (OR =0.1, 95% CI:0.012-0.87, P=0.03). CONCLUSION: Despite a population with greater co-morbidity and associated risk, outcomes remained consistent between early and later time-periods, indicating general improvements in care. The later cohort demonstrated fewer three-column osteotomies, less suboptimal realignments and concomitant reductions in adverse events and neurologic complications. This may suggest greater facility with less invasive techniques.