Canals and grooves for the supraclavicular nerves revisited: Anatomical and radiological study outlining their topography for clinical practice.

Objectives: Supraclavicular nerves cross the clavicle to provide sensory innervation to the skin over the clavicle, ventromedial shoulder region and upper part of the thorax. Although rare, they may variably perforate the clavicle throughout their course. Since the current literature lacks a comprehensive analysis of the resultant canals and grooves for the supraclavicular nerves, this study aimed to provide detailed morphometric and topographical data for clinical practice.

Materials and methods: In total, 524 dry clavicles and 200 CT images were assessed for the presence of canals or grooves for the supraclavicular nerves. Morphometric parameters were digitally measured, and correlated between dry bones and supraclavicular nerves' course in ten formaldehyde-preserved neck regions. Radiological observations were assessed for their suitability in preoperative planning.

Results: Twenty-two out of 524 dry clavicles (4.2%) featured a canal for the supraclavicular nerve, and a groove was present in 6 cases (1.1%). The average distances from the sternal and acromial ends to the closest margin of the canal or groove corresponded to the course of the intermediate supraclavicular nerve. A canal was detected in eight out of 200 CTs (4%) while a groove was not identified at all.

Conclusion: Although both variations are rare, canals for the supraclavicular nerves appear more frequently. Both canals and grooves for the supraclavicular nerves are indentations of the intermediate supraclavicular nerve. These data can be implicated in the management of clavicular fractures and surgical decompression of the neural entrapment within the canal or the groove.