The course of the median and radial nerve across the elbow: an anatomic study

Nerve transection has been described as complication of arthroscopic elbow arthrolysis. Therefore, the goal of this study was to define bony landmarks for intraoperative orientation regarding the location of the median and radial nerve.

In 22 formalin-fixated upper extremities, the radial and median nerves were dissected and marked with respect to their native course. A 3D X-ray scan was performed. The distances of the radial nerve to the radial head (R1), the capitulum (R2), and its lateral border (RC) were measured. The location of the radial nerve in relation to the transversal diameter of the humeral condyle (HC) was calculated. Similarly, the distances of the median nerve to the trochlea (M1), the medial border of the trochlea (M2), and its relation to HC were calculated.

The mean value for R1 was 8 mm (±2.9 mm), for R2 was 11.3 mm (±3.8 mm), and for RC was 10.6 mm (±5.1 mm). RC/HC averaged 24 % (±11 %). M1 averaged 11.7 mm (±5.2 mm), and M2 was 2.4 mm (±4.1 mm). M2/HC averaged 6 % (±9 %).

The radial nerve is located ventral to the central third of the capitulum. The median nerve lies ventral to the medial quarter of the humeral condyle. When performing arthroscopic arthrolysis, this information should be kept in mind during anterior capsulectomy.