Predicting radial nerve location using palpable landmarks

Area of Science:

• Anatomy
• Surgical anatomy
• Neuroscience

Background:

• The radial nerve (RN) is crucial for upper limb function.
• Precise localization of the RN and its branches is vital for surgical safety and efficacy.
• Existing anatomical references may lack sufficient detail for palpable landmark-based navigation.

Purpose of the Study:

• To predict the anatomical location of the radial nerve (RN) and its key divisions.
• To correlate RN and branch positions with easily palpable external landmarks on the humerus and radius.
• To provide quantitative data for surgical planning and anatomical education.

Main Methods:

• Dissection of 34 paired human upper limbs.
• Localization of the radial nerve at the humeral spiral groove (SG) and lateral intermuscular septum (LIS).
• Identification of the radial nerve's division into the posterior interosseous nerve (PIN) and radial sensory nerve (RSN), and the PIN's position at the anterior radial neck (AN).
• Measurement of humeral and radial lengths and correlation with nerve locations.

Main Results:

• The RN was located at the SG, averaging 48% of humeral length distal to the greater tuberosity.
• The RN pierced the LIS at an average of 38% of humeral length proximal to the lateral epicondyle (LE).
• The PIN/RSN division occurred approximately 1.0 cm distal to the LE.
• The PIN was identified at the AN, averaging 10% of radial length distal to the radial head's articular surface.

Conclusions:

• Palpable anatomical landmarks provide reliable reference points for locating the radial nerve and its branches.
• The quantitative data derived from this study can enhance surgical precision and reduce iatrogenic injury.
• This research offers valuable anatomical insights for orthopedic and neurosurgical procedures involving the posterior humerus and forearm.