Letter to the Editor: Commentary to "Anatomical Variations of the Suprascapular Notch and its Importance in Suprascapular Entrapment Neuropathy"
Abstract
With interest we read the article by Bagoji et al. reporting a study of the suprascapular notch (SSN) variations in relation to the suprascapular nerve entrapment (SNE). The authors reported a morphometric study of the SSN consisted of parametric measurements and shape typing besides correlating certain SSN variants to potential risk of SNE.
We strongly do not agree with the conclusions and have the following comments and concerns. Firstly, the presented scapula in Figure 6 in the study by Bagoji et al. shows one suprascapular foramen and the opening next to it is a scapular defect that is not related to the SSN.
Scapular defects are variant openings within the lamina of the scapula and are visible on some dry or wet scapulae as well as on some shoulder X-rays. These scapular defects (if present) appear in varying size and number and they are encountered more commonly within the infraspinous fossa, but they can be also observed within the supraspinous fossa.
Secondly, the W-shaped SSN variant, even though neither mentioned as a SSN type nor addressed as W-shaped type in previous studies, is well known related to the site of the variant bifid suprascapular ligament or of the variant anterior coracoscapular ligament attachment being partially ossified. This SSN type can relate to the SNE, but not due to its morphological shape.
The potential risk is a consequence of those aforementioned variant ligaments located internally within the SSN narrowing its vicinity. Thirdly, SSN geometric shape is not a direct influence in SNE per se.
SNE is more associated with the SSN stenosis manifested by reduced morphometric SSN margins (6) which can also appear due to the reported soft tissue variations (7, 8) and this is a limitation in dry bones studies. The authors' concluding statement that the V-shaped SSN is the most common causative factor in SNE was not driven from supporting findings.
The reported measurements and presented statistics by Bagoji et al. do not suggest any association of the V-shaped SSN to SSN stenosis in comparison to the other reported SSN types. Overall, the presented study by Bagoji et al. combined two methods of SSN classification.
One being based on the SSN observed shapes (9, 10) and one being based on the SSN morphometric measurements. However, this approach would be more meaningful if it linked to direct effect on the passing suprascapular nerve rather than the presented non-evidenced based speculations.