Variations in pelvic and other sagittal spinal parameters as a function of race in adolescent idiopathic scoliosis

A retrospective review of clinical and radiographic data from a multicenter adolescent idiopathic scoliosis (AIS) database. OBJECTIVE.: The purpose of this study was to perform a comprehensive radiographic evaluation of the differences in pelvic parameters between 2 groups (white and black) in a scoliotic population.

Increasingly, the importance of spinopelvic alignment and balance is appreciated as a major factor in the energy-efficient posture of the individual in the normal and diseased states. Pelvic incidence (PI) determines the lordosis of the patient and equations defining the interplay of pelvic parameters, lordosis, and kyphosis have been developed to guide surgical decision-making for spinal deformity. PI and thoracic lordosis have been previously shown to be increased in the AIS population.

Data were obtained from a prospective multicenter AIS database from a total of 1658 patients. We evaluated the 2 largest racial subsets in our database. We identified 421 whites and 115 black patients who met inclusion criteria. The parameters evaluated on preoperative full-length coronal and lateral radiographs were PI, sacral slope (SS), pelvic tilt, lumbar lordosis (LL), thoracic kyphosis, sagittal Cobb angle, and the shift of the sagittal C7 plumb line.

Age, gender, major and minor cobb angles were similar in the 2 groups. PI, pelvic tilt, and LL were found to be significantly greater in the black group when compared with the white group (black: 56.0, 13.9, and -63.6 vs. white: 52.5, 10.8, and -59.1).

In our study, significant differences were found in 3 of the 6 sagittal plane parameters between the 2 groups. With a larger PI, a larger LL is required in order maintain a neutral sagittal balance. Our results suggest that race may influence an individual's natural spinopelvic alignment, and serves as a reminder when planning surgical reconstruction for spinal deformity.