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The suprascapular nerve and its articular branch to the acromioclavicular joint: an anatomic study

https://doi.org/10.1016/j.jse.2010.09.004Get rights and content

Hypothesis

The suprascapular nerve and its articular branch innervate the acromioclavicular (AC) joint. Documenting the detailed anatomy of this innervation in the AC joint, including the pertinent surgical and anatomic relationships of the suprascapular nerve and its branches to the AC joint, will aid in the prevention of injury and the reduction of risk of denervation during shoulder surgery.

Materials and methods

Twelve shoulders from 6 embalmed human cadavers were bilaterally dissected to study the course of the suprascapular nerve and its motor and sensory branches.

Results

The sensory branch runs superiorly to the supraspinatus muscle towards the AC joint. The average distance from the supraglenoid tubercle to the nerve at the coracoid base was 15 mm. The average distance from the coracoclavicular ligaments to the nerve at the coracoid base was 6 mm. The average distance from the spinoglenoid notch to the sensory branch at the suprascapular notch was 22 mm. The average length of the sensory branch was 30 mm. In half of the specimen shoulders, the suprascapular artery accompanied the nerve at the suprascapular notch under the transverse scapular ligament.

Discussion

The innervation of the AC joint by the suprascapular nerve has been described, along with pertinent distances to anatomic landmarks. The sensory branch of the suprascapular nerve, which passed through the scapular notch inferior to the transverse scapular ligament, was found in 100% of the study specimens.

Conclusion

The sensory branch of the suprascapular nerve runs superiorly to the supraspinatus muscle towards the AC joint. The detailed information can be used to help decrease the risk of nerve injury during shoulder surgery and to aid in effectively diagnosing and treating AC joint-related disorders.

Section snippets

Materials and methods

Investigational Review Board approval was not required for this study.

Twelve shoulders from six embalmed human cadavers (5 women, 1 man) were bilaterally dissected. The deceased donors had an average age of 83 years (range, 68-91 years). Cadavers were embalmed using a standard preparation of embalming fluid composed of formaldehyde, methanol, and ethanol, which was injected into the carotid artery and also pumped into the organs and abdomen.

In each specimen the surgical exploration was

Results

The suprascapular nerve passed through the scapular notch inferior to the transverse scapular ligament in all 12 specimens. In 6 shoulders (50%), the suprascapular artery accompanied the nerve at the suprascapular notch under the transverse scapular ligament (Fig. 2). From the suprascapular notch, the suprascapular nerve coursed obliquely and laterally in the supraspinous fossa along the inferior surface of the supraspinatus muscle directly to the base of the scapular spine. From the base of

Discussion

The suprascapular nerve is responsible for most of the sensory innervations to the shoulder joint as well as to the supraspinatus and infraspinatus muscles of the rotator cuff.14 This nerve arises from the upper trunk and crosses the posterior triangle of the neck to the scapular notch, passing dorsally to the inferior belly of the omohyoid muscle and anterior to the trapezius. A number of authors have presented research on the path of the suprascapular nerve:

  • Shishedo et al12 gave the course of

Conclusion

The sensory branch of suprascapular nerve runs superiorly to the supraspinatus muscle toward the AC joint. The detailed information can be used to help decrease the risk of nerve injury during shoulder surgery and to aid in effectively diagnosing and treating AC joint-related disorders.

Disclaimer

The authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.

References (17)

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    The contradictory findings between trials published before and after 2017 could be attributed to a combination of increased technical success with US guidance and to the fact that the anterior approach may provide a more complete block of the shoulder joint. Cadaveric studies have demonstrated that a significant percentage of sensory and articular branches to the glenohumeral joint and SCJ actually split off from the main suprascapular nerve proximal to the transverse scapular ligament, thereby escaping blockade with the posterior approach [44–47]. Thus, from an anatomic standpoint, the anterior approach may provide a more complete block of the suprascapular nerve.

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