Suprascapular notch

Structure

This notch is converted into a foramen by the suprascapular ligament, and serves for the passage of the suprascapular nerve. The suprascapular vessels vary in number as well as in their course as they run at the suprascapular notch site. The suprascapular artery pass above the suprascapular ligament in most cases. The suprascapular vein may pass through the suprascapular notch or it may instead pass superior to the suprascapular ligament.

Types

Two main classification systems exist; others are modified approaches of the same principle.

Typing based on subjective observation of the suprascapular notch shape.

Introduced by and modified by There are six basic types of scapular notch:

• Type I: Notch is absent. The superior border forms a wide depression from the medial angle to the coracoid process.
• Type II: Notch is a blunted V-shape occupying the middle third of the superior border.
• Type III: Notch is U-shaped with nearly parallel margins.
• Type IV: Notch is V-shaped and very small. A shallow groove is frequently formed for the suprascapular nerve adjacent to the notch.
• Type V: Notch is minimal and U-shaped with a partially ossified ligament.
• Type VI: Notch is a foramen as the ligament is completely ossified.

Typing based on parametric measurements of depth to upper width ratio of the suprascapular notch

Introduced by and modified by There are five basic types of scapular notch:

• Type I: Depth larger than upper width.
• Type II: Depth equal to upper width.
• Type III: Depth is smaller than upper width.
• Type IV: Notch is a foramen.
• Type V: Discrete notch.

The second method of suprascapular notch typing yields more practical approach in clinical diagnosis of the suprascapular nerve entrapment.

Clinical significance

As the suprascapular nerve passes through the suprascapular notch, it is a common site of entrapment for the nerve.

Suprascapular notch stenosis is a narrowing of the notch internal space that can potentially compress the suprascapular nerve leading to suprascapular nerve entrapment. predicted the morphological pattern of the suprascapular notch stenosis revealing higher incidence in the discrete notch (Type V according to the parametric measurements typing system). There are two main suprascapular stenosis patterns:

• Vertical stenosis. Treated surgically by cutting the suprascapular ligament (ligamentectomy).
• Horizontal stenosis. Treated surgically by trimming the notch borders (osteoplasty).

The suprascapular nerve predictably passes through the suprascapular notch, so it is a good place for a local nerve block of the entire nerve.

Additional images

File:Suprascapular notch of left scapula - animation01.gif|Left scapula. Suprascapular notch shown in red. File:Suprascapular notch - animation02.gif|Animation. Suprascapular notch shown in red. File:Gray203.png|Left scapula. Dorsal surface. (Sup. notch visible at top center.) File:Anterior surface of scapula.jpg|Costal surface of left scapula. Suprascapular notch labeled at top center.

References

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References

1. (2015-01-01). "Chapter 38 - Anatomy of the Ventral Rami, Upper Trunk, and Its Divisions and Branches". Academic Press.
2. (2015). "The variable morphology of suprascapular nerve and vessels at suprascapular notch: a proposal for classification and its potential clinical implications". Knee Surg Sports Traumatol Arthrosc.
3. (2021). ""Suprascapular canal": Anatomical and topographical description and its clinical implication in entrapment syndrome.". Annals of Anatomy.
4. (2012-01-01). "Chapter 8 - Shoulder Girdle: Clavicle and Scapula". Academic Press.
5. (2020). "The morphological stenosis pattern of the suprascapular notch is revealed yielding higher incidence in the discrete type and elucidating the inevitability of osteoplasty in horizontally oriented stenosis". Knee Surg Sports Traumatol Arthrosc.
6. (2013-01-01). "31 - Proximal Neuropathies of the Shoulder and Arm". W.B. Saunders.
7. Bouche, P.. (2013-01-01). "Chapter 19 - Compression and entrapment neuropathies". Elsevier.
8. Wilkinson, Laura J.. "Defunct DOI".
9. Molloy, Robert E.. (2005-01-01). "Chapter 75 - Truncal Blocks: Intercostal, Paravertebral, Interpleural, Suprascapular, Ilioinguinal, and Iliohypogastric Nerve Blocks". Churchill Livingstone.