Ossified Superior Transverse Scapular Ligament: Case Report and Literature Review

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.