Two main classification systems exists with others being modified approaches of the same principle.
Typing based on subjective observation of the suprascapular notch shape. Introduced byHrdicka 1942and modified byRengachary et al. 1979.
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.[4]
Typing based on parametric measurements of depth to upper width ratio of the suprascapular notch introduced byNatsis et al. 2007and modified byPolguj et al. 2011.
There are five basic types of scapular notch:
The second method of suprascapular notch typing yields more practical approach in clinical diagnosis of the suprascapular nerve entrapment.[5]
Clinical significance
As the suprascapular nerve passes through the suprascapular notch, it is a common site of entrapment for the nerve.[1][6][7]
Suprascapular notch stenosis is a narrowing of the notch internal space that can potentially compress the suprascapular nerve leading to suprascapular nerve entrapment. Al-Redouan et al. 2020 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). Two main suprascapular stenosis pattern:[5]
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.[8][9]
Habermeyer, Peter; Magosch, Petra; Lichtenberg, Sven (2006). Classifications and Scores of the Shoulder. Springer. ISBN978-3-540-24350-2. LCCN2005938553.
Rengachary, S. S.; Burr, D.; Lucas, S.; Hassanein, K. M.; Mohn, M. P.; Matzke, H. (1979). "Suprascapular entrapment neuropathy: a clinical, anatomical, and comparative study". Neurosurgery. 5 (4): 447–451. doi:10.1227/00006123-197910000-00007. PMID534049.
Natsis, K; Totlis, T; Tsikaras, P; Appell, H J; Skandalakis, P; Koebke, J (2007). "Proposal for classification of the suprascapular notch: a study on 423 dried scapulas". Clinical Anatomy. 20 (2): 135–139. doi:10.1002/ca.20318. PMID16838269. S2CID43546741.
Polguj, Michał; Jędrzejewski, Kazimierz; Podgórski, Michał; Topol, Mirosław (2011). "Morphometric study of the suprascapular notch: proposal of classification". Surgical and Radiologic Anatomy. 33 (9): 781–787. doi:10.1007/s00276-011-0821-y. PMID21590338. S2CID25861966.