Hopital Saint Antoine, Sorbonne Universite, Faculté de Medecine, Campus Saint-Antoine, France.
Hopital Saint Antoine Paris, Clinique des Maussins-Nollet Paris, Hôpital privé des peupliers Paris, Sorbonne Universite, Faculté de Medecine, Campus Saint-Antoine, France.
Orthop Traumatol Surg Res. 2020 Jun;106(4):771-774. doi: 10.1016/j.otsr.2020.02.006. Epub 2020 Apr 29.
The posterior branch of the medial antebrachial cutaneous nerve (MACN) is at risk to be damaged during cubital tunnel surgery. The purpose of this study was to identify the location of the posterior branch of the MACN (PBMACN) in relation to surgical landmarks pertinent in cubital tunnel surgery.
We performed an anatomical study on 20 limbs from 13 fresh cadavers. The nerve was dissected from 10cm proximal to 10cm distal of the medial epicondyle. We measured the distance between the nerve and the medial epicondyle, and also the distance separating the PBMACN from the ulnar nerve passage between the two heads of the flexor carpi ulnaris. Measurements were performed with the elbow at 45° and 90° of flexion, as well as in full pronation and supination.
After its emergence from the main trunk of the MACN, the posterior branch ran anteriorly to the medial epicondyle, taking an oblique direction toward the ulnar shaft. The PBMACN was in average 2.53cm under the medial epicondyle when the elbow was flexed at 45°, and 2.96cm when the elbow was flexed at 90°. Average distance between the PBMACN and the penetrating point of the ulnar nerve within the flexor carpi ulnaris was 1.54cm when the elbow was flexed at 45°, and 1.62cm when the elbow was flexed at 90°. Pronation and supination positions of the forearm did not significantly modify our measurements.
Understanding the position of MACN posterior branch during ulnar nerve release surgery at the elbow may help in preventing iatrogenic injury. According to our measurements, incision and superficial dissection anterior to the medial epicondyle or distal to the ulnar nerve penetrating point between the two heads of the flexor carpi ulnaris should be avoided or done with an elbow flexed at 90°.
正中神经前臂内侧皮支（MACN）的后支在肘管手术中容易受损。本研究旨在确定 MACN 后支（PBMACN）在与肘管手术相关的手术标志点的位置。
我们对 13 具新鲜尸体的 20 个肢体进行了解剖学研究。神经从内侧上髁近端 10cm 到远端 10cm 处进行解剖。我们测量了神经与内侧上髁之间的距离，以及 PBMACN 与尺神经在尺侧腕屈肌两头之间的穿行点之间的距离。测量在肘部屈曲 45°和 90°以及完全旋前和旋后时进行。
在后支从 MACN 的主干分出后，它向内侧上髁前方走行，呈斜向尺骨方向。当肘部屈曲 45°时，PBMACN 平均位于内侧上髁下方 2.53cm 处，当肘部屈曲 90°时，位于内侧上髁下方 2.96cm 处。当肘部屈曲 45°时，PBMACN 与尺神经在尺侧腕屈肌内穿行点之间的平均距离为 1.54cm，当肘部屈曲 90°时，距离为 1.62cm。前臂旋前和旋后位置并未显著改变我们的测量值。
了解肘部尺神经松解术中 MACN 后支的位置，可能有助于预防医源性损伤。根据我们的测量结果，应避免在肘前内侧上髁或尺神经在尺侧腕屈肌两头之间的穿行点远端进行切口和浅层解剖，或在肘部屈曲 90°时进行。
