The iliac buttress. A computed tomographic study of sacral anatomy

Area of Science:

• Orthopedics
• Radiology
• Biomedical Engineering

Background:

• Spinal instrumentation often requires secure sacral fixation.
• Assessing the anatomical feasibility of novel fixation techniques is crucial.

Purpose of the Study:

• To evaluate the safety and feasibility of intrasacral rod insertion into the lateral sacral masses.
• To determine the prevalence of iliac buttressing of the sacrum in patients undergoing CT scans.

Main Methods:

• Computed tomographic (CT) scans of 50 patients (25 male, 25 female) were analyzed.
• Measurements of lateral sacral mass width were taken to assess rod insertion potential.
• Coverage of the posterolateral sacrum by the ilia was evaluated for iliac buttressing.

Main Results:

• All patients demonstrated lateral sacral masses wide enough for safe 7 mm rod insertion down to S2.
• The mean lateral intrasacral mass measurement was 28 mm (minimum 17 mm).
• Iliac buttressing was observed in 96% of males and 88% of females (92% overall).

Conclusions:

• Intrasacral rod insertion into the lateral sacral masses is anatomically feasible and appears safe.
• Sufficient iliac buttressing is present in most patients, potentially enhancing biomechanical stability.
• These findings suggest improved sacral fixation methods for spinal instrumentation.