Canal for the Intermediate Branch of the Supraclavicular Nerve

A transclavicular course for branches of the supraclavicular nerve can be seen in about 5% of the population. These canals are slightly more common on the left side and are thought to be formed by enclosure of the nerve within the clavicle during development.

One canal that is sometimes seen through the superior border of clavicle along its middle third transmits the intermediate (middle) branch of the supraclavicular nerve (this is incorrectly referred to as the medial fascicle in Borderlands). The canal can be duplicated in some people, in which case two lucencies are seen on radiographs.

While usually asymptomatic, patients can present with compression of the intermediate (middle) branch of the supraclavicular nerve within the canal. In addition, a stretch injury to the neck can result in trauma to the nerve as it traverses through the clavicle. In these cases, bony decompression of the nerve can alleviate symptoms.

References

• Freyschmidt J, Brossmann J, Wiens J, Sternberg A. Clavicle and Sternoclavicular Joint. In Freyschmidt's Köhler and Zimmer: Borderlands of normal and early pathologic findings in skeletal radiography. Fifth revised edition. Thieme (2003). P 307.
• Jelev L, Surchev L. Study of variant anatomical structures (bony canals, fibrous bands, and muscles) in relation to potential supraclavicular nerve entrapment. Clin Anat. 2007 Apr;20(3):278-85.
• Keats TE and Anderson MW. Atlas of Normal Roentgen Variants That May Simulate Disease. 8th edition, page 453. Mosby (2004).
• Tubbs RS, Salter EG, Oakes WJ. Anomaly of the supraclavicular nerve: case report and review of the literature. Clin Anat. 2006 Oct;19(7):599-601.