Differences in Demographic and Radiographic Characteristics between Patients with Visible and Invisible T1 Slopes on...

Area of Science:

• Orthopedics
• Radiology
• Spine Surgery

Background:

• The T1 slope is a critical parameter for cervical spine surgical planning.
• T1 slope visibility on radiographic images can vary, impacting surgical assessment.
• Prevalence and characteristics of invisible T1 slope cases are not well-understood.

Purpose of the Study:

• To investigate the prevalence of invisible T1 slopes.
• To compare demographic and radiographic characteristics between patients with visible and invisible T1 slopes.

Main Methods:

• A pilot study involving 60 outpatients undergoing cervical radiography.
• Patients were categorized into visible (V) and invisible (I) T1 slope groups.
• Measured parameters included C2-7 sagittal vertical axis (SVA) and C2-7 angle in neutral, flexion, and extension.

Main Results:

• 46.7% of patients had an invisible T1 slope (Group I).
• Group I exhibited a significantly larger C2-7 SVA in males compared to Group V (p < 0.05).
• A trend of larger C2-7 SVA was observed in Group I for females, though not statistically significant (p = 0.362).

Conclusions:

• The T1 slope was frequently invisible, particularly in males with a high C2-7 SVA.
• C2-7 angles in neutral and flexion positions did not significantly differ between groups.
• A greater C2-7 angle in extension was noted in the visible T1 slope group.