Surface projection of the posterior interosseous nerve and artery as they exit the supinator and interosseous foramen respectively : A cadaver study

Purpose: The purpose of this study was to develop a method for locating surface projections of the posterior interosseous nerve (PIN) and posterior interosseous artery (PIA) as they exit the supinator muscle and interosseous foramen respectively. Methods: Distances from the vertical and transverse planes through the lateral epicondyle of the humerus to the exit point of the PIN through the supinator and the PIA through the interosseous foramen were measured on 10 upper extremities from 5 cadavers. Average distances were used to find coefficients in terms of the thumb interphalangeal joint widths. Results: The mean transverse plane distance from the lateral epicondyle to the exit points of the PIN and PIA were 79.38 mm (~4.0 IPJ widths) and 90.62 mm (~4.5 IPJ widths) respectively. The mean vertical plane distance from the radius to the exit points of the PIN and PIA were 9.45 mm (~0.5 IPJ widths) and 10.86 mm (~0.5 IPJ widths) respectively. Conclusions: The results of this study present a method to assist clinicians in avoidance of iatrogenic outcomes with the application of various treatments such as dry needling and acupuncture.