Study design: Prospective radiographical analysis using the cranial center of gravity (CCG) of sagittal vertical axis (SVA) in elderly asymptomatic individuals.
Objective: To determine sex differences and age-related correlations of CCG and relationships between CCG and other spinopelvic parameters/health-related quality of life (HRQOL) measures.
Summary of background data: Few studies have investigated CCG in a relatively large sample of elderly asymptomatic individuals.
Methods: Six hundred seventy-one healthy participants older than 50 years (mean age, 72.9 yr; range, 50-92 yr) were enrolled. Whole-spine standing radiographs were obtained. The following radiographical measurements were obtained: (1) CCG-C7 SVA, (2) C7-SVA, (3) CCG-SVA, (4) C2-C7 lordosis angle, (5) thoracic kyphosis, (6) lumbar lordosis, (7) pelvic incidence, and (8) sacral slope. HRQOL measures included the EuroQol-5D and Oswestry Disability Index. Pearson product-moment correlation coefficients were calculated between pairs of radiographical measures and HRQOL.
Results: Sex differences were observed in CCG-C7 SVA, CCG-SVA, C2-C7 Cobb angle, thoracic kyphosis, and pelvic incidence. Three SVA parameters (CCG-C7 SVA, C7-SVA, CCG-SVA) rapidly increased between seventh and ninth decades and were approximately 40, 80, and 120 mm, respectively, in the ninth decade. Age-related correlations were observed for all parameters without pelvic incidence, and the CCG measurement correlated the most with age. Furthermore, CCG-SVA correlated with other spinopelvic measurements and HRQOL.
Conclusion: Age-related changes and sex difference in craniopelvic alignment were analyzed. Craniopelvic alignment became rapidly positive with age, particularly in the eighth decade. The CCG measurement correlated the most with age and may be a useful index marker of global spinal balance in decision making for surgical treatment of adult deformity involving cervical and thoracolumbar lesions.
Level of evidence: 4.