Anatomical Parameters for Occipital Condyle Screws: An Analysis of 500 Condyles Using CT Scans.

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Radiology

Background:

• Occipitocervical fixation is crucial for stabilizing the craniocervical junction.
• Accurate screw placement is vital for surgical success and patient safety.
• Understanding occipital condyle anatomy is essential for guiding surgical instrumentation.

Purpose of the Study:

• To determine occipital condyle dimensions (length, width, height).
• To establish the medialization angle for safe occipital condyle screw placement.
• To analyze variations in these measurements based on sex and age.

Main Methods:

• Retrospective observational study analyzing CT scans of 250 patients.
• Measurements of condyle length, width, height, and medialization angle were taken.
• Data were compared between sexes and age groups, excluding patients with fractures, tumors, or infections.

Main Results:

• Average condyle length: 18.6 mm, width: 10.5 mm, height: 11.3 mm.
• Average medialization angle: 23°.
• Men exhibited significantly longer, wider, and taller condyles; women had a significantly steeper medialization angle. No age-related differences were found.

Conclusions:

• Occipital condyle dimensions and medialization angles vary significantly by sex.
• Preoperative planning using patient-specific anatomy is critical for safe occipital condyle screw placement.
• These anatomical insights aid in optimizing outcomes for occipitocervical fixation procedures.