Summary
The mean distance from the SN to the acromion is approximately 6 cm, significantly greater in males than females. However, distances from the tip of the coracoid to various arthroscopic landmarks and the SN's position in the suprascapular notch are not significantly affected by gender or height.
Abstract
Background
Arthroscopic suprascapular nerve (SN) release is challenging due to the nerve's anatomical location. This study investigates the anatomical relationships between the SN, bony landmarks, and adjacent structures
Methods
This cadaveric study analyzed 22 shoulders from 11 Thiel-embalmed cadavers (6 male, 5 female). Measurements were categorized into four groups: (1) Bony landmarks—distances from the SN to the posterolateral and anterolateral acromion (D1, D2), the tip of the coracoid process (D3), and the superior glenoid (D4), measured with digital calipers. (2) Arthroscopic landmarks—distances from the origin of the coracoacromial (CA) ligament at the acromion to its posterior insertion at coracoid (S1) , and from the posterior insertion of CA ligament to the conoid ligament which adjacent to the suprascapular notch(S2). (3) Position of the SN in the suprascapular notch—width of the notch (L1) and distance from the SN to the lateral side of the notch (L2). (4) Angles—angle from the posterior acromion to the suprascapular notch (A1), representing the angle for the Neviaser portal, and the angle from the tip of the coracoid process to the SN and the suprascapular notch (A2), representing portals from the lateral side of the shoulder
Results
The mean distances D1, D2, D3, D4, S1 and S2 were 58.34±6.59 mm, 59.50±5.22 mm, 46.49±3.12 mm, 39.26±4.93 mm, 28.18±4.51 mm and 29.93±6.19 mm, respectively. The correlation coefficients of these measurements (D1, D2, D3, D4, S1, and S2) with height were 0.51, 0.11, 0.30, 0.45, 0.08, and 0.28, respectively. Distances D1 and D2 showed significant gender differences: males had longer distances (D1: 63.38±1.13 mm vs. 52.29±0.89 mm, P<0.05; D2: 63.09±1.11 mm vs. 55.20±1.04 mm, P<0.05). The mean widths L1, L2 were 9.93±1.34 mm and 4.67±1.27 mm respectively. Finally, The mean angles A1, A2 were 83.73±16.71 degrees and 84.72±6.83 degrees, respectively.
Conclusion
The mean distance from the SN to the acromion is approximately 6 cm, significantly greater in males than females. However, distances from the tip of the coracoid to various arthroscopic landmarks and the SN's position in the suprascapular notch are not significantly affected by gender or height.
Study design : Cadaveric anatomical study
Keyword : suprascapular nerve entrapment, anatomical study, arthroscopic decompression