The Impact of Critical Shoulder Angle on The Incidence of Atraumatic Rotator Cuff Tear

Objectives: To examine how often unilateral atraumatic Rotator cuff tears (RCTs) occur and how the critical shoulder angle (CSA) relates to it. Background: RCTs are a prevalent orthopaedic injury, significantly impacting individuals' quality of life, particularly on older adults. Methods: This observational study involved 54 patients aged 40-65 years (23 males, 31 females) with confirmed unilateral atraumatic RCTs without prior shoulder surgeries. All participants underwent medical history taking, clinical examination, and radiological investigations. Results: The participants in our study had a mean age (±SD) of 52.9 ± 7.91 years, with the standard being female—31 (57.41%). The tenderness was localised in 21 patients (38.89%). The location of tendon tear was Supraspinatus+ Infraspinatus in 36 (66.67%) patients. The abduction had a mean (±SD) value of 138.2 ± ْ 22.23 . The external rotation had a mean (±SD) value of 33.2 ± ْ 16.84 . Internal rotation in 90° abduction had a mean (±SD) value of 51 ± 20.32. CSA was with a mean (±SD) value of 41 ± ْ 13.82 . Rotator cuff pathology was significantly correlated with CSA (P = 0.000), as it was found that a higher CSA was associated with this condition. Conclusion: The CSA is a valuable radiological marker for identifying rotator cuff injuries. The incidence of rotator cuff pathology is significantly correlated with the CSA, and RCT participation was higher among patients with higher CSA values.