CT scan method accurately assesses humeral head retroversion

Area of Science:

• Orthopedic Surgery
• Radiology
• Anatomy

Background:

• Humeral head retroversion measurement lacks standardized, accurate methods.
• Existing literature presents controversial findings regarding normal ranges and measurement accuracy.

Purpose of the Study:

• To determine normal ranges for humeral head retroversion.
• To assess the accuracy of different measurement techniques for humeral head retroversion.

Main Methods:

• Utilized four measurement methods (radiographic, CT scan, computer-assisted, direct) on 65 cadaveric humeri.
• Assessed the distance between the humeral head central axis and the bicipital groove.

Main Results:

• Computed tomography (CT) scan methods accurately measure humeral head retroversion; radiographic methods do not.
• Normal retroversion values were established relative to the transepicondylar axis (17.9°) and trochlear tangent axis (21.5°).
• The distance to the bicipital groove was consistently 7.0 mm.

Conclusions:

• CT scans are the preferred method for accurately measuring humeral head retroversion.
• Patient-specific anatomical landmarks or contralateral measurements are recommended when CT is unavailable.