Cervical Lordosis Increases with Age in Adult Spinal Deformity: A Cross-Sectional Study of Nonoperative Patients

Abstract

Introduction It is theorized that with age and degeneration, the cervical spine becomes progressively more kyphotic; however, there are no studies which support these conclusions. We performed a radiographic analysis of patients with adult spinal deformity (ASD) and hypothesized that cervical lordosis would decrease with aging. Patients and Methods The nonoperative arm of a prospective multicenter database of patients with ASD was analyzed. Inclusion criteria were patients > 18 years old meeting any one of the following criteria: Coronal Cobb > 20 degrees, C7-S1 sagittal vertical axis (SVA) > 5 cm, pelvic tilt (PT) > 25 degrees, or thoracic kyphosis (TK) > 60 degrees, and the patients who did not undergo surgery. Nonidiopathic causes of scoliosis, history of spine surgery, and age < 18 years were excluded. Coronal and sagittal radiographic parameters were collected with particular interest to cervical sagittal parameters. Curves were classified into Schwab type. Age groups were separated into group 1: < 40 years, group 2: 41 to 60 years, and group 3: > 60 years. Statistical analysis was performed with Wilcoxon rank sum test for continuous variables with a p value < 0.05 as significant. Results Of the 491 patients in the database, 373 met inclusion criteria for the study and 269 had complete radiographic data for analysis. With increasing age, there were an overall slight increase in body mass index and a statistically significant increase in the Charlson Comorbidity Index. There were no differences in Schwab curve type prevalence between groups. The mean cervical lordosis (CL) increased with age (1.6 ± 10.6, 7.1 ± 13.3, and 11.8 ± 13.2 in groups 1, 2, and 3, respectively, p = 0.04,< 0.01, and < 0.01. Interestingly, there was a corresponding increase in T1 slope between groups 1, 2, and 3 without an increase in thoracic kyphosis. Meanwhile, the C2–7 SVA remained the same (3.0 ± 1.2, 2.7 ± 1.6, and 2.7 ± 1.8, groups 1, 2, and 3, respectively, p = 0.17, 0.88, 0.32). With increasing age, there was a decrease in lumbar lordosis (LL), increase in PT, and increase in SVA. Conclusion CL actually increases with age in nonoperative ASD patients while the thoracic kyphosis remained the same. The LL decreased whereas the PT and SVA increased. The types of curve distributions were similar between all the age groups.