[Anatomic aspects of the posterior interosseous nerve in the proximal approach to the radius].
BACKGROUND
It is important to understand the spatial relation between the posterior interosseous nerve (PIN), the radial head, and the supinator muscle in pronation or supination. The objectives of this study are: to describe of the PIN and how it is related with the supinator muscle; to measure the distance between the PIN and the radius while the forearm is pronated or supinated; to determine the best interval for the approach of proximal radius.


METHODS
We conducted this study with 18 fresh cadavers. A lateral approach was made, and identification of the PIN and how it was related with the supinator muscle was described. We made the measurements and they were analyzed.


RESULTS
The PIN penetrated the supinator muscle 3.8 cm +/- 0.48 from the epicondyle and its location was always intramuscular. It was never in contact with the periosteum. The PIN split in 4-7 branches (for the extensor muscles) after a mean of 6 cm +/- 0.75 (4.8-8.0), following the exit from the muscle; with pronation the nerve moved 1.03 cm +/- 0.31.


CONCLUSIONS
The interval between the extensor digitorum communis (EDC) and the extensor carpi ulnaris (ECU) was easy to identify and proved to be a safe zone for approaching the PIN. In our study no contact between the nerve and the periosteum of the radius was found, but it should be kept in mind when dissecting the muscle from the radius proximally. We found a minimum distance of 4.8 cm from the nerve's exit from supinator muscle with respect to the radial head. This is the safe zone recommended when cutting the muscle. Pronation moved the nerve away 1 cm, so this maneuver is advisable for the approach of proximal radius.
Vergara Amador
Enrique
E
Departamento de Cirugía, Universidad Nacional de Colombia, Bogotá. enriquevergaraa@yahoo.com
D000293:Adolescent; D000328:Adult; D006801:Humans; D008875:Middle Aged; D011826:Radial Nerve / Q000033:anatomy & histology*; D055815:Young Adult