A new method of predicting radial nerve location: a cadaveric study

Area of Science:

• Anatomy
• Orthopedic Surgery
• Surgical Navigation

Background:

• The Radial Nerve (RN) is crucial for upper limb function.
• Accurate localization of the RN is vital for preventing iatrogenic injury during surgical procedures, particularly humerus fracture fixation.
• Existing methods for RN identification may lack precision in the middle and lower humerus regions.

Purpose of the Study:

• To develop and present a novel method for predicting the safe zone of the Radial Nerve (RN) in the middle and lower upper limb.
• To establish anatomical reference points for precise RN localization.
• To provide data that can assist surgeons in identifying the RN using surface markers.

Main Methods:

• Dissection of 60 Radial Nerves from 30 adult cadavers (20 males, 10 females).
• Selection of Acromial Angle, Olecranon, and Lateral Epicondyle of Humerus as reference points.
• Measurement of distances and identification of intersection points to define RN distribution areas using Python3.11 and PyCharm2023.3.4.

Main Results:

• The study identified an absolute safe zone with no RN distribution and a relative safe zone with <5% RN distribution probability.
• The absolute safe zone is defined by specific percentages along the Acromial Angle-Olecranon and Acromial Angle-Lateral Epicondyle lines.
• The relative safe zone is delineated by slightly different percentage points along the same anatomical lines.

Conclusions:

• A new, reliable method for predicting the Radial Nerve's safe zone on the middle and lower humerus has been established.
• This method utilizes easily identifiable surface anatomical landmarks.
• The findings are directly applicable to improving surgical outcomes in humerus fracture fixation by minimizing the risk of Radial Nerve injury.