A Cadaveric Study of Radial Nerve Course and its Clinical Implications on Radial Nerve Block at Elbow

Introduction: Upper limb nerve blocks are done commonly by brachial plexus (C5-T1) blocks via supraclavicular, infraclavicular approaches. Sometimes a single peripheral nerve needs additional block with local anaesthetic to achieve adequate block. Peripheral nerve blocks are useful for minor surgical procedures in a single nerve distribution. Aim: To study the course and clinical significance of the radial nerve in 50 cadaveric upper limbs. Materials and Methods: A cross-sectional study was conducted on 50 intact dissected upper limbs. The upper limbs were obtained from the Department of Anatomy, Sri Ramachandra Medical College from August 2020 to December 2020. Radial nerve was exposed by routine dissection in all the upper limbs and its entire course was studied and observed for any variation. The distance from the biceps tendon to the radial nerve at the elbow, distance of the radial nerve in the Lateral Intermuscular Septum (LIS) from the epicondyles at the elbow were measured. The results obtained were statistically analysed using SPSS version 16.0. Results: In present study, the mean distance of the radial nerve in the LIS to the medial epicondyle was 12.4±0.31 cm and to the lateral epicondyle was 12.1±0.28 cm. The mean distance from the biceps tendon to the radial nerve at the elbow was 1.75±0.22 cm. Conclusion: From the present study, it can be inferred that effective peripheral radial nerve block can be achieved by blocking the nerve 1.75 cm lateral to the biceps tendon at the elbow 3 cm above the elbow crease. This can be made comfortable to the patient and more precise by ultrasound localisation of the radial nerve.