Anatomical Factors/Countermeasures In/Against Iatrogenic Injury Of The Deep Branch Of Radial Nerve In The Thompson Approach Via Middle And Proximal Segments Of Forearm

This study aimed to investigate the anatomical factors affecting iatrogenic injury of the deep branch of radial nerve during the Thompson approach and to propose corresponding countermeasures. Thompson approach was used to measure the horizontal/longitudinal distance from the position where the deep branch of radial nerve leaves the supinator to the ulnar margin of extensor carpi radialis brevis/humeroradial joint line. Measurements were obtained by using 48 adult cadaver specimens, which were used in teaching. We observed the lentor situation of the extensor digitorum and extensor carpi radialis brevis in proximal forearm segments and measured the distance from the deep branch of radial nerve to the humeroradial joint line at the lateral side of the radius in the neutral position of forearm rotation. The horizontal distance from the point where the deep branch of radial nerve leaves the inferior margin of supinator to the ulnar margin of extensor carpi radialis brevis was 1.3 +/- 0.3 cm. The distance to the humeroradial joint line was 61.3 +/- 17.6 mm. The distance to the lentor extent of extensor digitorum and extensor carpi radialis brevis at the distal part of humeroradial joint was 7.1 +/- 2.1 cm. The distance from the deep branch of radial nerve to the humeroradial joint line at the lateral side of the radius is 3.2 +/- 0.6 mm. Anatomical factors are observed in iatrogenic injury of the deep branch of radial nerve during the Thompson approach. Stretching the extensor digitorum before the dissection of the supinator is hazardous.