The Aging World of Spinal Deformity Surgery

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Assess epidemiological patterns in the rate and age distribution of surgically treated adult spinal deformity (ASD) over the last decade. BACKGROUND: Advances in patient selection, preoperative optimization, operative technique, and postoperative care have influenced trends in surgical management of ASD. However, nationwide epidemiological data of surgically treated ASD is lacking. METHODS: Adults who underwent corrective ASD surgery between 2010-2022 were identified from a large insurance claims database. Age, sex, year, region, and insurance plan distribution were extracted. Yearly trends in case counts and mean age were assessed using linear regression. Incidence rate ratios were calculated to evaluate differences in case rates. RESULTS: Among 141,604 surgically treated ASD patients, incidence increased from 4.5 to 15.5cases per 100,000, an increase of 1.2cases per 100,000 every year over the study period (P<0.001). Mean age increased from 63.3 to 66.7years, an increase of 2.5years every 10 years over the study period (P<0.001). Incidence rates also increased with age, with a peak of 88.5cases per 100,000 in 65-69 year olds. Female incidence rate was 90.9cases per 100,000 and male incidence rate was 78.4cases per 100,000. Regionally, Midwest had the highest incidence rate, and Northeast had the lowest incidence rate. Most (63.8%) patients were covered by commercial insurance, but Medicare had higher incidence rates than commercial insurance (71.7 Medicare vs. 57.1 Commercial cases per 100,000). Medicare incidence rates increased from 1.5 to 4.6cases per 100,000 while Commercial insurance incidence rates increased from 2.9 to 9.8cases per 100,000 (P<0.001). CONCLUSION: Between 2010-2022, surgically treated ASD rates rose by nearly 250%, with the average age of the operative patients increasing by 3.4years. As surgical volume for ASD continues to grow, continued efforts to improve outcomes and payment models will be necessary for sustainability. LEVEL OF EVIDENCE: IV.