Changes in Spinopelvic Parameters Between Standing and Sitting Postures: A Systematic Review and Meta-analysis

Area of Science:

• Spinal Biomechanics
• Orthopedic Surgery
• Radiographic Analysis

Background:

• Current spinal deformity surgery often overcorrects alignment based on standing posture.
• Significant disparities exist between standing and sitting spinal alignment.
• Understanding positional spinal changes is crucial for surgical outcomes.

Purpose of the Study:

• To quantify the ratio-of-differences in spinal alignment between standing and sitting postures.
• To investigate the influence of sex and age on these positional alignment variations.

Main Methods:

• A systematic review and meta-analysis of published literature was conducted.
• Searched 4 databases, adhering to PRISMA 2009 guidelines.
• Included 38 papers with 5423 patients.

Main Results:

• Sitting posture resulted in a more positive sagittal vertical axis (+29.5 mm) and greater pelvic tilt (+16.7 degrees).
• Sacral slope and lumbar lordosis were reduced in sitting (15.0 and 21.1 degrees, respectively).
• Age and sex subgroups showed variations, particularly in pelvic tilt and lumbar lordosis.

Conclusions:

• Sitting posture alters spinal alignment, affecting sagittal vertical axis, pelvic tilt, sacral slope, and lumbar lordosis.
• Age and sex significantly influence these spinal alignment changes.
• Consideration of these positional variations is essential for effective spinal realignment surgery planning.