Optimal Positioning for Single-Position Lateral Lumbar Interbody Fusion

Area of Science:

• Spine surgery
• Orthopedics
• Biomechanical analysis

Background:

• Minimally invasive spinal surgery often utilizes the right lateral decubitus position (RLDP).
• Maintaining physiologic lumbar and pelvic alignment in RLDP is crucial for surgical outcomes.
• The effect of varying hip positions on spinopelvic parameters in RLDP requires quantification.

Purpose of the Study:

• To quantify the impact of different hip flexion angles on lumbar lordosis (LL) and spinopelvic parameters in the RLDP.
• To determine the optimal hip configuration in RLDP that most closely replicates standing alignment.
• To inform surgical positioning for lateral lumbar interbody fusion.

Main Methods:

• Thirty healthy volunteers underwent lateral lumbar radiography in a standing position and five RLDP configurations.
• Radiographs were taken with varying hip flexion: neutral, 30°, and 60° bilateral flexion, and 30° and 60° unilateral flexion (right hip).
• Lumbar lordosis, pelvic tilt, sacral slope, and pelvic incidence were measured and compared to standing alignment.

Main Results:

• All RLDP positions demonstrated a significant decrease in LL compared to standing.
• The 30° right hip flexion with the left hip neutral (30FN) position showed the smallest deviation in LL (-4.9°).
• The 30FN position also resulted in mild anterior pelvic rotation, with decreased pelvic tilt and increased sacral slope.

Conclusions:

• Hip position critically influences lumbar and pelvic alignment during RLDP.
• The 30FN hip configuration provides the closest approximation to standing alignment and spinopelvic harmony in RLDP.
• This finding is significant for optimizing patient positioning during lateral lumbar interbody fusion procedures.