The methodology utilized in this study is known as a retrospective cohort study. The aim was to analyze how surgical techniques and outcomes for treating adult cervical deformities have evolved. Surgery to repair cervical deformity has gained acceptance as a therapeutic option in recent years due to the aging of the population and the rise in the incidence of the condition. 

Although the understanding of this method has grown and surgical techniques have improved dramatically over the years, researchers still need to learn how these factors will affect the treatment of cervical deformities. Patients with cervical deformity who were 18 years of age or older and who had the complete health-related quality of life and radiographic data at baseline and up to 2 years after treatment were included. Radiographic and surgical specifics were also part of the descriptive analysis. 

Based on when they had surgery, patients were divided into 2 categories: early (2013-2014) and late (2015-2017). Changes in surgical, radiological, and clinical outcomes were compared using univariate and multivariate regression analysis. Overall, 119 patients with cervical deformity met the study’s criteria for inclusion. In the 1st group, there were 72 patients; in the 2nd, there were 47. There was no difference in age, frailty, deformity, or cervical rigidity, but the late group had a higher Charlson Comorbidity Index (1.3 vs. 0.72) and greater cerebrovascular disease (6% vs. 0%, P<0.05). There were fewer 3-column osteotomies performed on the late group, even after accounting for baseline deformity and age (OR=0.18, 95% CI: 0.06-0.76, P=0.014). Patients in the late group were less likely to have a moderate or high Ames horizontal modifier (71.7% vs. 88.2%) and to have overcorrected pelvic tilt (4.3% vs. 18.1%, P<0.05) at the most recent follow-up.

There were fewer adverse outcomes (OR=0.15, 95% CI: 0.28-0.8, P=0.03) and neurological problems (OR=0.1, 95% CI: 0.012-0.87, P=0.03) in the late group compared to the early group after adjusting for baseline deformity, age, levels fused, and 3-column osteotomies. There was no significant difference in outcomes between the early and later time periods, despite the fact that the population now has more comorbidities and related risks. 

Fewer 3-column osteotomies, fewer suboptimal realignments, and fewer adverse events and neurological problems were seen in the later cohort. This could be indicative of increasing skill with non-invasive methods.