Study of variant anatomical structures (bony canals, fibrous bands, and muscles) in relation to potential supraclavicular nerve entrapment

Abstract

Since the definition of supraclavicular nerve entrapment syndrome by Gelberman et al. (Gelberman et al. [1975] J. Bone Joint Surg. Am. 57:119) a number of clinical cases of this specific entrapment neuropathy have been reported. In all these cases, the nerve injury has been attributed to the location of the supraclavicular nerve branch in a narrow canal in the clavicle. However, in the anatomical literature, variations in the course of the supraclavicular nerves have not only been ascribed to bony canals but also to abnormal fibrous and muscular structures. Considering the fact that the existence of a narrow site with rigid walls along the course of a nerve is essential for the development of an entrapment neuropathy, our study examines all the variant anatomical structures with a possible role in supraclavicular nerve entrapment. We describe three groups of anatomical structures with close relation to the course of the supraclavicular nerves-transclavicular canals, fibrous bands, and unusual muscular structures. Based on the characteristics of the variations found, for the first time, we suggest that in addition to the bony canals through the clavicle certain fibrous and muscular structures could also be an anatomical basis for supraclavicular nerve entrapment syndrome.

Collective secondary cremation in a pit grave: A unique funerary context in Portuguese Chalcolithic burial practices

“…In clinical literature, this perforation is considered a rare anatomical variant of the clavicle. This canal seems to result from an unusual course of the supraclavicular nerve and is mainly studied due to its potential relation to supraclavicular nerve entrapment (Jelev and Surchev, 2007). This morphological trait is also rarely described in past human populations.…”

A novel variant of the cleidocervicalis muscle with clinical implications for nerve compression/entrapment

“…b Drawing illustrating the key relationships of the CC with nearby structures. CL clavicle, EJV external jugular vein, ICA internal carotid artery, OH omohyoid, SCM sternocleidomastoid, SH sternohyoid trapezius muscle [1,2]. In light of the current evidence, consideration of the presence of the cleidocervicalis muscle in patients with unexplained shoulder pain should also be considered.…”

Supraclavicularis proprius muscle associated with supraclavicular nerve entrapment

“…Impingement of the SN could be evoked from muscular and fibrous bands crossing the nerve, clavicular canals where the nerve passes through, clavicular fractures, and callus formation following clavicular fracture [7,9].…”

“…Previous cadaveric and imaging studies have revealed the presence of canals in the clavicle through which the nerve traverses [7,16,19]. SN entrapment syndrome can also be caused by an aberrant fibrous band attaching the SN to the superior surface of the clavicle [16].…”

“…Contraction of this aberrant muscle could result in compression of the SN, referred in the literature as SN entrapment syndrome. The compression phenomena may evoke shoulder pain and anterior chest numbness [2,7]. This study aims to present a rare case of SP muscle which is co-related with SN entrapment in the supraclavicular fossa.…”