Background The median and radial nerves are at risk of iatrogenic injury when performing arthroscopic arthrolysis with anterior capsulectomy. Although prior anatomic studies have identified the position of these nerves, little is known about how elbow positioning and joint insufflation might influence nerve locations. Questions/purposes In a cadaver model, we sought to determine whether (1) the locations of the median and radial nerves change with variation of elbow positioning; and whether (2) flexion and joint insufflation increase the distance of the median and radial nerves to osseous landmarks after correcting for differences in size of the cadaveric specimens. Methods The median and radial nerves were marked with a radiopaque thread in 11 fresh-frozen elbow specimens. Three-dimensional radiographic scans were performed in extension, in 90°flexion, and after joint insufflations in neutral rotation, pronation, and supination. Trochlear and capitellar widths were analyzed. The distances of the median nerve to the medial and anterior edge of the trochlea and to the coronoid were measured. The distances of the radial nerve to the lateral and anterior edge of the capitulum and to the anterior edge of the radial head were measured. We analyzed the mediolateral nerve locations as a percentage function of the trochlear and capitellar widths to control for differences regarding the size of the specimens. Results The mean distance of the radial nerve to the lateral edge of the capitulum as a percentage function of the capitellar width increased from 68% ± 17% in extension to 91% ± 23% in flexion (mean difference = 23%; 95% confidence interval [CI], 5%-41%; p = 0.01). With the numbers available, no such difference was observed Each author certifies that he or she, or a member of his or her immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research 1 editors and board members are on file with the publication and can be viewed on request. Clinical Orthopaedics and Related Research 1 neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use. Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained. This work was performed at the Department of Anatomy, University of Cologne, Cologne, Germany. regarding the location of the median nerve in relation to the medial border of the trochlea (mean difference = 5%; 95% CI, À13% to 22%; p = 0.309). Flexion and joint insufflation increased the distance of the nerv...