The sub pronator approach to the coronoid process

Area of Science:

• Orthopedic Surgery
• Anatomy

Background:

• The coronoid process is crucial for elbow stability.
• Anteromedial fractures of the coronoid process require surgical intervention.
• Understanding the anatomical relationship between surgical approaches and nerves is vital for patient safety.

Purpose of the Study:

• To describe a novel anteromedial surgical approach to the coronoid process.
• To characterize the position of median nerve motor branches relative to this approach.
• To evaluate the impact of elbow and forearm positioning on nerve proximity during surgery.

Main Methods:

• Sixteen anteromedial approaches were performed on fresh anatomical specimens.
• The distance between the median nerve's motor branches and the trochlea was measured in various elbow positions (flexed, extended) and forearm rotations (pronation, supination).
• Measurements were taken with the elbow extended and forearm supinated, extended and forearm pronated, and flexed at 90° and forearm supinated.

Main Results:

• The mean distance between the second motor branch of the median nerve and the medial trochlea was significantly smaller when the forearm was pronated (5 mm ± 3 mm) compared to supinated positions (13 mm ± 3 mm extended, 11 mm ± 4 mm flexed).
• No significant difference was found between the two supinated positions.
• The subpronator approach provides reliable exposure of the anteromedial facet of the coronoid process.

Conclusions:

• The subpronator approach is a reproducible and safe method for accessing the anteromedial coronoid process.
• Forearm supination during the subpronator approach effectively displaces the median nerve's motor branches, reducing the risk of iatrogenic injury.
• This approach allows visualization up to the anterior bundle of the medial collateral ligament insertion.