Sacropelvic Parameters and L5 Spondylolysis: Computed Tomography Analysis

Area of Science:

• Orthopedic Surgery
• Radiology
• Spine Research

Background:

• Previous studies suggest a link between pelvic incidence (PI) and sacral table angle (STA) with spondylolysis.
• However, no study has comprehensively analyzed multiple sacropelvic parameters simultaneously for their association with L5 spondylolysis.

Purpose of the Study:

• To determine the association between various sagittal sacropelvic parameters and L5 spondylolysis.
• To identify which sacropelvic parameters are significant predictors of L5 spondylolysis.

Main Methods:

• Retrospective analysis of 202 computed tomography (CT) scans from patients over 16 years old.
• Exclusion criteria included abnormal anatomy, prior spine/hip/pelvis surgery, and spinal pathology.
• Measured parameters: sacral anatomic orientation (SAO), PI, pelvic thickness (PTH), femoro-sacral posterior angle (FSPA), STA, and sacral kyphosis (SK).

Main Results:

• Significant differences in SAO, PI, STA, and SK were observed between patients with and without L5 spondylolysis.
• Logistic regression identified PI (OR 1.074) and STA (OR 0.822) as significant predictors of spondylolysis.
• PI showed significant correlations with PTH, FSPA, and SK in both spondylolysis and normal groups.

Conclusions:

• Increased pelvic incidence (PI) is associated with L5 spondylolysis.
• Decreased sacral table angle (STA) may represent chronic remodeling secondary to spondylolysis and is linked to increased risk.
• High PI or low STA in adolescents/young adults with back pain should raise suspicion for occult L5 spondylolysis.