Anatomical aspects regarding the endoscopic release of the nervus interosseus anterior

Background: Decompression of the anterior interosseous nerve can be performed in an open operative exploration or endoscopically. Using an endoscopic decompression superficial anatomical landmarks serve as reference point. The aim of the study was to determine the location of the distribution of the median nerve in relation to the elbow joint in order to facilitate preparation during endoscopic decompression.

Methods: The median nerve and the anterior interosseous nerve were dissected in 31 human specimens with regard to the elbow joint. The superficial anatomical landmark was the intercondyle line between the medial and lateral epicondyles. The distance between the origination of the anterior interosseous nerve of the median nerve was measured in relation to the intercondyle line.

Results: The anatomical preparation was done using 62 adult cadaveric upper extremities. 11 specimens were formalin fixed and 20 specimens were fresh frozen cadaveric upper extremities. The average of the intercondyle distance was 7.2 cm ± 0.5 (min. 5.8; max. 7.8). The anterior interosseous nerve originated from the median nerve in average 39 mm ± 18 (min. 8; max. 80) distal to the intercondyle line. In 12 cases the distance was within the first 2 cm. There was only a correlation between the length of the upper arm and the nerve junction.

Conclusions: The anterior interosseous nerve originated from the median nerve in average 4 cm distal to the intercondyle line. Although there was a distribution under 2 cm in around 20 % of the cases. This is very important with regard to the endoscopically technique and should be considered.