Background and Aim: The purpose of this study was to evaluate the anatomical constancy of the direct small branches of the proper digital nerve. Methods: A total of 208 digital nerves of the index, long, ring, and little fingers from 13 cadavers were studied. For each digital nerve, the number of direct small branches was counted at the proximal and middle phalanx levels. In addition, the diameter of these branches was measured at the level of the branch bifurcation. We also measured the diameter of the proper digital nerve at the level of the distal interphalangeal (DIP) joint. Results: The direct small branches of the proper digital nerve were anatomically constant among the index, long, and ring fingers. The average number of direct small branches was 2.7 at the proximal phalanx level and 2.3 at the middle phalanx level. At the level of the DIP joint, the average thickness of the proper digital nerve was 0.85 mm in the index finger, 0.84 mm in the long finger, 0.72 mm in the ring finger, and 0.49 mm in the little finger. Conclusion: In this study, we verified the anatomical constancy of the direct small branches of the proper digital nerve. The size of these branches at the proximal phalanx level was similar to that of the corresponding proper digital nerve at the level of the DIP joint. Therefore, these nerve branches at the proximal phalanx could be applied to the creation of various sensate flaps for the reconstruction of the fingertip injuries.
