Objective To make further exploration of the clinical application of tricyclic mutual crosses localization combined with nerve segmentation in the localization of dorsal interosseous nerve on the body surface through anatomical study of the dorsal interosseous nerve and its muscle branch. Methods Seventy upper limb specimens of thirtyfive adult cadavers were dissected precisely to reveal the courses of dorsal interosseous nerve and its muscle branch and each bifurcation point. Determined the body surface position of the dorsal interosseous nerve through the "tricyclic mutual crosses localization method" and the "nerve segmentation method".Thirty adult patients with dorsal interosseous nerve injury were selected and located with tricyclic mutual crosses combined with nerve segmentation on the body surface

and the accuracy of the results was observed during the operation. Results Among the 30 patients

27 cases obtained accurate location and the other 3 cases failed

including 1 case of extensor digitorum branch and 2 cases of extensor indicis branch.The four bifurcation points of the dorsal interosseous nerve (O

O1

O2

O3) have important guiding significance for the subarea and segmentation of the body surface.The tricyclic mutual crosses localization could be more accurate.But there were large variation in extensor digitorum branch and extensor indicis branch

thus the accuracy of tricyclic mutual crosses localization is poor.Conclusion According to the tricyclic mutual crosses localization combined with nerve segmentation

the localization of dorsal interosseous nerve and its muscular branches could be more accurate

and the location of nerve injury could be identified.