Possible factors associated with sagittal malalignment recurrence after pedicle subtraction osteotomy

Area of Science:

• Spine surgery
• Orthopedics
• Radiology

Background:

• Pedicle subtraction osteotomy (PSO) is a surgical technique used to correct spinal deformities.
• Sagittal alignment is crucial for spinal function and patient outcomes.
• Malalignment recurrence after PSO can lead to suboptimal results and revision surgery.

Purpose of the Study:

• To investigate factors associated with malalignment recurrence after PSO.
• To identify patient demographics and radiographic parameters that predict recurrence.
• To understand the biomechanical implications of malalignment recurrence.

Main Methods:

• Retrospective analysis of full spine radiographs in 66 patients who underwent PSO.
• Preoperative, 3-month postoperative, and follow-up measurements of sagittal alignment parameters.
• Screening of follow-up CT scans for pseudarthrosis and sacroiliac joint abnormalities.

Main Results:

• 42% of patients experienced malalignment recurrence (SVA C7 increase > 70 mm).
• Elderly patients (average age 62.8 years) were at higher risk for recurrence.
• Loss of lumbar lordosis and increased pelvic incidence were associated with recurrence, with pseudarthrosis being a key factor.

Conclusions:

• Malalignment recurrence after PSO is a significant concern, particularly in elderly patients.
• Pseudarthrosis and subsequent loss of lumbar lordosis are critical factors contributing to recurrence.
• Understanding these factors can help in optimizing surgical planning and patient selection to minimize recurrence risk.