Background: The purpose of our study was
to quantify the dimensions of a surgically safe zone along the proximal
part of the radius, from the posterolateral aspect.
Methods: The posterolateral approach between
the anconeus and the extensor carpi ulnaris was performed in thirty-two
cadaveric specimens, and the posterior interosseous nerve was exposed.
Forearms were measured from the radial styloid process to the radiocapitellar
joint. The distance from the capitellum to the point where the posterior
interosseous nerve crossed the radial shaft and the angle between
the nerve and the shaft were measured with forearms in pronation
Results: Pronation of the forearm allowed safe
exposure of at least the proximal thirty-eight millimeters of the lateral
aspect of the radius, with an average proximal safe zone of 52.0 ± 7.8 millimeters. Supination decreased this proximal
safe zone to as little as twenty-two millimeters and an average
of 33.4 ± 5.7 millimeters. The angle formed
by the posterior interosseous nerve and the radial shaft in supination
averaged 47.4 6.8 degrees; this decreased to 27.8 ± 6.7 degrees with pronation.
Conclusions: Approaching the lateral aspect
of the proximal part of the radius is safest in pronation.