Complete ossification of the superior transverse scapular ligament (STSL) converts the suprascapular notch into a rigid tunnel, predisposing the suprascapular nerve to compression, especially when the calibre is < 4 mm. Three dry adult scapulae (two right, one left) from the King Saud University collection were examined. Notch type, ossified-STSL shape, and tunnel/bridge dimensions were measured with a 0.01-mm digital caliper. All specimens displayed full STSL ossification forming a true foramen—two fan-shaped, one band-shaped. Mean tunnel opening was 6.16 × 2.52 mm (circumference 18.96 mm). The bony bridges averaged 11.10 × 4.70 mm, leaving an effective width < 4 mm in every case. Finite-element modelling of similarly constricted tunnels shows contact stress on the nerve rises throughout abduction, with marked peaks near full elevation. Although total STSL ossification is reported in only 4 - 10 % of scapulae, the extreme narrowing observed here lies well within the recognised “danger zone” for neuropathy. Overhead athletes and manual workers may experience dynamic compression that routine examination misses; thus, high-resolution CT or MRI is advised when electromyography suggests suprascapular nerve injury. Where conservative care fails, arthroscopic release achieves pain and strength improvement in 90 - 96 % of patients. Even isolated complete STSL ossification can create critically narrow suprascapular foramina that amplify biomechanical stress on the nerve; early imaging and timely arthroscopic release are key to preventing irreversible deficit.
KEY WORDS: Suprascapular Nerve; Nerve Compression Syndrome; Scapula; Ligament; Ossification.
BATARFI, M. A. Ossified superior transverse scapular ligament: case report and literature review. Int. J. Morphol., 43(6):1879-1882, 2025.
