Objective: Medial elbow incision is obligatory for cubital tunnel syndrome surgical treatment. However, the terminal branches of both the medial antebrachial cutaneous nerve (MACN) and the medial brachial cutaneous nerve (MBCN) are likely to be harmed using the current incision technique. The aim of this study was to seek a new incision to avoid damaging the branches of MACN and MBCN during the operation for cubital tunnel syndrome. Methods: Ten fresh frozen cadaver upper extremities and 20 clinical cases (elbows) were analyzed. A conventional incision and a new incision were used in the cadaveric specimens and the clinical cases, respectively. The medial epicondyle was set as the reference landmark to quantify the location of the terminal branches, with the elbow at full extension. The numbers of the terminal branches and their locations were noted for MACN and MBCN, and the locations of the posterior branch of the MACN were recorded in the elbow medial incision. Results: The average numbers of MACN’s posterior terminal branches were 2.6 ± 1.6 and 4.4 ± 2.4 in the cadaveric specimens and clinical cases, respectively. The average number of MBCN’s terminal branches was 2 ± 0.87 in the cadaveric specimens. The MACN’s posterior terminal branches were located at 19 and 45 mm, respectively, measuring from the medial epicondyle. And the posterior branch of MACN was always located in between the medial epicondyle and the basilic vein, and the average distance was 10 ± 6 mm to the medial epicondyle. We could preserve all the MBCN’s terminal branches in the new incision. The MACN’s posterior terminal branches could be perfectly exposed by the use of the antegrade dissection technique, finding the MACN’s posterior branch in advance. Conclusions: The new elbow medial incision technique could reduce the risk of injuring the terminal branches from the MBCN. The medial epicondyle and the basilic vein are reliable anatomical landmarks to identify the posterior branch of the MACN. An antegrade method of dissection can effectively identify and avoid the injury to the terminal branches of the MACN in the elbow medial incision.
