Normal Global Sagittal Alignment Radiographic Parameters in Patients Without Spinal Deformity.

Area of Science:

• Orthopedics and Spine Surgery
• Radiology and Imaging
• Biomechanical Engineering

Background:

• Global sagittal alignment is critical for spinal health and function.
• Establishing normative data is essential for identifying spinal deformity.
• Age and sex are known demographic factors that can influence spinal alignment.

Purpose of the Study:

• To determine reference ranges for global sagittal alignment parameters.
• To stratify these parameters by age and sex in a healthy cohort.
• To provide a baseline for comparison in spinal deformity assessment.

Main Methods:

• Retrospective cohort study of 518 patients without spinal deformity.
• Biplanar full-body spine X-rays were analyzed.
• Global sagittal alignment parameters were measured and stratified by age and sex.

Main Results:

• Age was associated with increased cranial sagittal vertical axis to the sacrum (CrSVA-S) and hip (CrSVA-H) but decreased to the knee (CrSVA-K).
• Male sex was associated with greater CrSVA-S, CrSVA-H, and ankle (CrSVA-A) compared to females.
• No significant sex difference was found for CrSVA-K.

Conclusions:

• This study provides normative reference values for global sagittal alignment.
• Findings support operative planning and enhance understanding of spinal deformity.
• Age and sex are significant determinants of normal sagittal alignment.