Computed tomography of the normal radioulnar joints

Area of Science:

• Orthopedics
• Radiology
• Anatomy

Background:

• Understanding the complex biomechanics of the radioulnar joints is crucial for diagnosing upper extremity injuries.
• Previous studies have often overlooked the nuanced movements within the proximal and distal radioulnar articulations.

Purpose of the Study:

• To precisely define the anatomy and normal motion of the proximal and distal radioulnar joints.
• To establish osseous landmarks for measuring rotational and translational movements in these articulations.

Main Methods:

• Computed tomography, sectional radiography, and photography were utilized on eight cadaveric specimens.
• Specific osseous landmarks were identified to quantify rotation at the glenohumeral, proximal radioulnar, and distal radioulnar joints.

Main Results:

• Independent rotation of the ulna was found to be absent.
• Normal translatory motion at the distal radioulnar articulation was observed, which could be mistaken for subluxation.

Conclusions:

• The study provides a detailed anatomical and kinematic map of the radioulnar joints.
• Accurate interpretation of distal radioulnar joint motion is essential to avoid misdiagnosis of subluxation.